Biochar Effects on Soil Properties and Yield of Maize in Northern Region, Ghana

Biochar Effects on Soil Properties and Yield of Maize in Northern Region, Ghana | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Biochar Effects on Soil Properties and Yield of Maize in Northern Region, Ghana Abdul-Latif Abdul-Aziz, Issah Alidu Abukari, Moustapha Mahamane Galadima, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6127479/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 14 You are reading this latest preprint version Abstract Soil degradation and declining crop productivity are persistent challenges in global agriculture, particularly in sub-Saharan Africa. While biochar application has gained recognition as a sustainable soil amendment, this study systematically evaluates the effects of different biochar feedstocks and application rates on soil fertility and maize productivity in Ghana. Three agricultural waste materials (rice husk, groundnut husk and sawdust) produced as biochar were evaluated under 5 application rates for improved grain yield, yield components and soil characteristics during the 2022 and 2023 cropping seasons under field experimental conditions. The treatment consisted of 2 factors: three biochar and five levels of biochar application rates (0, 2, 4, 6, and 8 t ha-1). Soil chemical properties, including pH, organic matter, and nutrient availability, were analysed alongside maize yield parameters. The study demonstrates that groundnut husk biochar is the most effective at enhancing soil fertility and boosting maize yields, with the highest application rate (8 t ha⁻¹) leading to remarkable grain yield increases—up to 218.2% in 2022 and 106.3% in 2023. Soil organic matter content increased significantly, ranging from 89.6–343.4%, while nitrogen availability peaked at 220% in 2022 and 70% in 2023. Maize yield showed a strong positive correlation with soil fertility parameters, except for the harvest index. These findings provide critical insights into optimising biochar use for sustainable maize production in similar conditions worldwide, demonstrating its potential to enhance soil health and long-term agricultural productivity. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Highlights The application of biochar significantly improved soil pH, organic matter content, and nutrient availability, leading to enhanced overall soil health. Applying biochar at a rate of 8 tons per hectare resulted in the highest maize grain yield, with increases of up to 218.2% in 2022 and 106.3% in 2023. Biochar from groundnut husks outperformed rice husk and sawdust biochar in enhancing soil fertility and maize yield. This study confirmed that biochar is an effective and sustainable soil amendment, especially at higher application rates. A strong positive relationship was established between maize yield and the improved chemical properties of the soil, except the harvest index, underscoring biochar's potential to boost agricultural productivity. 1. Introduction Biochar is a carbon-rich material created through biomass pyrolysis in oxygen-limited conditions. It has gained considerable attention as a sustainable solution for improving soil health, enhancing agricultural productivity, and mitigating climate change. Its ability to enhance soil structure, nutrient retention, and water-holding capacity is particularly vital for resource-constrained farming systems [1,2]. These properties are essential for maize (Zea mays L.), a staple crop widely cultivated in tropical and subtropical regions where soil fertility often poses a challenge [3,4]. Recent advancements in biochar production technologies have significantly increased the material's adaptability and effectiveness for agricultural applications. Modern pyrolysis techniques, such as continuous-feed reactors and gasification systems, enable precise control over temperature and heating rates, allowing for the tailoring of biochar's physicochemical properties to meet specific agricultural needs [5,6]. Additionally, artisanal and low-cost pyrolysis methods, specifically designed for smallholder farmers in resource-limited settings, provide a practical way to convert locally available biomass into biochar, increasing accessibility [7]. The effectiveness of biochar is largely influenced by the characteristics of its feedstock, pyrolysis conditions, and application rates. Feedstocks such as woody biomass produce biochar with high porosity and stable carbon content, which is ideal for improving soil aeration and creating favourable conditions for microbial life [8]. In contrast, biochar from agricultural residues, such as maize stalks and banana peels, tends to be richer in nutrients, thereby enhancing soil fertility directly [8,9]. Emerging research has highlighted the significance of feedstock-specific innovations, indicating that biochar's nutrient release patterns and carbon stability can vary considerably across different biomass types [10,11]. Moreover, studies indicate that the application rate of biochar plays a crucial role in determining its impact on crop productivity. Moderate application rates (e.g., 5–10 tons/ha) consistently improve soil fertility and crop yields, while excessive rates can disrupt soil nutrient balance or pH, leading to diminished returns [12,13]. In maize production systems, biochar has shown variable yield responses depending on soil fertility levels. In acidic and nutrient-poor soils, the application of biochar often leads to significant yield increases, whereas the benefits are less noticeable in fertile soils [14,15]. In Ghana and other semi-arid regions, biochar made from crop residues has demonstrated promise in improving nitrogen use efficiency and enhancing soil organic matter, thereby contributing to sustainable maize production under challenging conditions [16]. Despite these findings, gaps remain in understanding how biochar properties, application rates, and specific soil-crop systems interact, particularly in smallholder farming contexts. This study aims to investigate the effects of different biochar types and application rates on soil properties and maize productivity. By evaluating biochars produced from various feedstocks and applied at different rates, the research seeks to provide practical recommendations for optimising biochar use in maize farming systems, ultimately enhancing soil health, crop productivity, and environmental sustainability. 2. Materials and methods 2.1. Experimental area The experiment was carried out at the research field of Savannah Agriculture Research Institute (SARI) in the Tolon District of Northern Ghana. The site is situated in the Guinea Savannah Agroecological Zone, between 9° 25′ N and 00° 58′ W. The rainfall pattern is unimodal, occurring from May to October, with peaks in August and September. The average annual rainfall is 93.9 mm, and the season lasts six months, mostly from April to September. The area is further identified by a long dry season (4–6 months), typically from November to April. Throughout the growth season, there are intermittent dry spells that can last up to 2–4 weeks. Temperatures are highest from March to April, and lowest in December due to north-east trade winds pushing the Inter Tropical Convergence Zone further south. The average monthly minimum and maximum temperatures are 26.6°C and 35.6°C, respectively, while the average yearly temperature is 29.7°C [17]. The rainfall and temperature patterns monitored at Nyankpala from January to December during the 2022 and 2023 cropping seasons are shown in Figs. 1 and 2 . Figure 1 near here Figure 2 near here 2.2. Soil sampling, preparation and analysis Soil samples were collected before and after the experiment from different replicate plots. Before the experiment, five soil cores were taken from each replicate plot at 0–15 cm depth. These core samples were combined to form a composite sample. After the experiment, additional soil samples were obtained from each plot. The collected soil samples were air-dried and passed through a 2-mm mesh sieve. This sieving process ensured that the soil particles were of consistent size for further analysis. Particle size analysis was conducted using the hydrometer method, as described by [18]. Fifty grams of the sampled soil were weighed and used in the analysis to determine the distribution of different particle sizes in the soil. Soil pH was measured by preparing a suspension of 10 grams of soil in 25 ml of water. The pH of this suspension was then determined using a pH meter. The soil organic carbon content was determined using the method described by [19]. A 0.5-gram portion of the soil sample was weighed and used in this analysis. The total nitrogen content of the soil was determined using the Kjeldahl method. One gram of the sampled soil was weighed and used for this analysis. Available phosphorus in the soil was determined using the Bray 1 method, as described by [20]. Again, one gram of the soil sample was weighed and used for this analysis. Cation Exchange Capacity (CEC) was determined by leaching ten grams of the sampled soil with neutral 1M ammonium acetate, following the guidelines provided by [21]. These standardized laboratory procedures were followed to ensure accurate and consistent analysis of the soil samples. 2.3. Soil characteristics The result of the analysis is evident of common characteristics of savanna soil as the experimental site is sand silt in texture and slightly acidic in reaction (pH 5.5–6.5) with a very low organic carbon content (< 20 g/kg) (Table 1 ), Total nitrogen and exchangeable cations were less than 1g/kg and 5 cmol(+)/kg) respectively with available P being less than 10 mg/kg [22](Table 1 ). Table 1 Physico-chemical characteristics of the soil at horizon 0–15 cm. Parameter Test value Sand (%) 61.88 Silt (%) 32.00 Clay (%) 6.12 Texture Sandy silt pH (1:2.5 H 2 O) 5.53 O.C (g /kg) 2.93 N (g /kg) 0.29 P (mg/kg) Exchangeable cations (cmol(+)/kg): 8.02 K 0.19 Na 0.26 Ca 1.60 Mg 1.00 Table 1 near here 2.4. Biochar preparation Farm and municipal waste (rice husk, groundnut husk, and sawdust) generated in the farmer fields and sawmills were collected and charred to obtain biochar. The biochar was produced in a fabricated drum pyrolysis unit with a nominal peak temperature of 500°C. The rice husk, ground nut husk, and sawdust were all crushed and then passed through a 2 mm filter. The resulting biochar types were stored for chemical analysis. 2.5. Biochar characteristics The pH of ground air-dried rice husk, groundnut husk, and sawdust biochar materials was measured in water and 0.01M CaCl 2 at a biochar to liquid ratio of 1:10. The carbon and nitrogen contents were determined using a Leco Trumac Carbon Nitrogen Sulphur version 1.3 Analyzer. Water soluble and then ammonium extractable bases (Ca, Mg, K, and Na) in biochar types were extracted progressively with de-ionized water and 1M ammonium acetate, and the concentrations were measured using a Perkin Elmer Analyst 800 Atomic Absorption Spectrometer. Table 1 shows the chemical composition of the biochar (Table 2 ). Table 2 The chemical composition of biochar derived from rice husk, groundnut husk, and sawdust Feedstock type pH H 2 O (1:2.5) % N Fixed C C/N ratio Avail. P (mg/kg) Ca (mg/kg) Mg (mg/kg) K (mg/kg) Na (mg/kg) Rice husk 8.02 0.67 13.62 142 129 144 208.98 304.20 303.47 Groundnut 8.54 1.37 58.13 42.43 1300 152 2500 7500 6200 Sawdust 7.31 1.09 11.58 156 89 492 165.24 440.7 416.12 Table 2 near here 2.6. Experimental design Three agricultural waste materials (rice husk, groundnut husk and sawdust) produced as biochar were evaluated under 5 application rates for improved grain yield, yield components and soil characteristics during the 2022 and 2023 cropping seasons under field experimental conditions. The treatment consisted of 2 factors, namely, 3 biochar (rice husk, groundnut and sawdust) and 5 levels of biochar application rates (0, 2, 4, 6, and 8 t ha − 1 ). The whole plot area used was 4 m x 20 m with 2 m alley each between whole plots and replicates. Each subplot measured 4 m x 4 m with 1 m alley between them. The biochar was applied to the soil by broadcasting and manually incorporated into the soil with a hoe to a depth of approximately 15 cm. The Wandaata maize variety was used as the test crop. Three seeds were planted per stand, which was later thinned to two after two weeks from planting using a planting distance of 80 cm x 40 cm. A blank basal application of NPK 14:18:18 was done across plots, including the control. Weeding of the field was done on the second, fifth, and eighth weeks after planting. 2.7. Statistical analysis The data collected were subjected to ANOVA using GenStat statistical software, and the test treatments were differentiated using the Least Significant Differences at a 5% probability level. 3. Results and discussion 3.1. Growth parameters 3.1.1. Plant height The impact of various types of biochar on plant height was evaluated over two growing seasons (refer to Table 3 ). In 2023, no significant differences in plant height were observed among the different biochar types, indicating uniform effects on vertical growth for that year. However, results from 2022 showed that plants treated with groundnut husk biochar achieved the greatest height, measuring 149 cm. This suggests that groundnut husk biochar may possess unique properties, such as high nutrient content or effective soil conditioning, that promote enhanced vegetative growth. Previous studies support these findings, indicating that biochar can improve plant growth through mechanisms such as increased nutrient availability, improved water retention, and enhanced soil structure [24, 25]. Figure 3 illustrates the effect of different biochar application rates on plant height over the two years. In 2023, all application rates resulted in significant increases in plant height compared to the control group, with higher rates (6–8 t ha -1 ) producing the most substantial improvements. In contrast, only application rates of 4 t/ha and above led to significant differences in plant height in 2022. These variations may be attributed to differences in weather conditions or the cumulative effects of biochar over time. Biochar's ability to retain nutrients and enhance microbial activity may strengthen with prolonged use [38, 26]. Notably, plants treated with 2 t/ha of biochar experienced a significant increase in height in 2023 compared to 2022. This inter-annual difference may reflect the gradual enhancement of soil fertility by biochar, as seen in other studies where biochar's benefits grew over time due to improved soil organic matter and microbial interactions [16, 27]. These findings highlight the potential of biochar as a sustainable soil amendment for enhancing crop growth. However, the effects of biochar appear to be influenced by the application rate, type of biochar, and environmental conditions. In particular, groundnut husk biochar seems to be a promising option, likely due to its higher rates of nutrient release and favourable interactions with the soil. These results are consistent with reports indicating that biochars derived from agricultural residues often outperform those derived from forestry residues in terms of nutrient availability [9, 17]. 3.1.2. Stalk weight The analysis indicated that stalk weight did not vary significantly across different types of biochar in either year (Table 3 ). This consistency suggests that the contribution of biochar to stalk biomass production relies more on its general soil amelioration properties than on its specific type. Previous studies support this observation, highlighting that the impact of biochar on plant biomass is often linked to its ability to enhance soil properties, such as nutrient availability and water retention, rather than unique chemical characteristics associated with particular biochar types [28]. Figure 4 illustrates the influence of biochar application rates on stalk weight. A clear trend emerged where higher biochar application rates resulted in significant increases in stalk weight across both years. In 2022, stalk weights reached a peak of 3.5 t ha⁻¹ for the 8 t ha⁻¹ application rate, while the control group recorded the lowest stalk weight at 1.1 t ha⁻¹. Similar patterns were observed in 2023, with the highest and lowest stalk weights corresponding to the 8 t ha⁻¹ and control treatments, respectively (3.5 t ha⁻¹ and 2.0 t ha⁻¹). These findings align with earlier studies, such as those by [24], which reported that biochar improves nutrient retention and soil structure, ultimately leading to increased plant biomass production. Notably, stalk weights across all treatments in 2023 exceeded those of 2022, except for the 8 t ha⁻¹ application rate, which remained consistent across both years. This suggests that the cumulative effects of biochar, including enhanced microbial activity, increased organic matter, and improved soil fertility, may have contributed to the higher biomass observed in 2023 [15,29]. The plateau observed at the 8 t ha⁻¹ application rate further indicates that this level may represent an optimal threshold under the study's conditions. Beyond this point, additional biochar may yield diminishing returns, a phenomenon noted in other studies [30]. Overall, the study emphasizes the potential of biochar as a sustainable soil amendment for increasing stalk weight, particularly at higher application rates. Table 3 The effect of biochar type on the plant height, stalk weight, and number of cobs of maize grown during the 2022 and 2023 cropping seasons Biochar type Plant height (cm) Stalk weight (t/ha) Cob count (No/plot) Cropping season 2022 2023 2022 2023 2022 2023 Rice husk 142b † 150a 2.2a 3.1a 75.6a 59.4a Groundnut husk 149a 144a 2.4a 3.3a 74.4a 63.5b Saw dust 141b 148a 2.2a 3.2a 77.9a 63.7b Lsd (5%) 4.70 7.80 0.30 0.31 5.46 3.71 CV 4.2 6.8 17.0 12.4 9.3 7.7 † Values with the same lowercase letters in a column in the year are not significantly different at p < .05. Table 3 near here Figure 3 near here Figure 4 near here 3.2. Yield components of maize 3.2.1. Cob number The number of cobs per plant showed significant variability between 2022 and 2023, particularly in response to biochar application (Table 3 ). In 2023, rice husk biochar produced the highest number of cobs per plant, unlike in 2022, when no significant differences were observed among treatments. This finding suggests that rice husk biochar may offer specific advantages for maize reproductive traits, possibly due to its nutrient profile or effects on soil properties. This observation aligns with the findings of [30], who demonstrated biochar's potential to improve soil fertility and enhance plant productivity. Across both years, significant differences in cob number were observed based on the rate of biochar application (Fig. 5 ). The highest numbers of cobs consistently occurred at the 8 t ha⁻¹ application rate, while the control plots exhibited the lowest numbers. This underscores the effectiveness of biochar in enhancing soil health and crop productivity through improved nutrient retention and soil structure, as noted [24]. Notably, the increase in cob number over time reflects the cumulative effects of biochar, with enhanced soil properties contributing to better performance in the second year. Similarly, [15] and [29] highlighted the long-term benefits of biochar on soil health and crop productivity. Interestingly, the unamended control showed similar cob numbers in both years, reinforcing that the observed increases are primarily due to biochar application. The consistent performance of the 8 t ha⁻¹ rate suggests it may be an optimal dosage under the study conditions, as diminishing returns beyond certain application rates have been observed in other studies [31]. Figure 5 near here 3.2.2. Cob weight The type of biochar used had a negligible impact on cob weight over both years, as no significant differences were noted (Table 4 ). This indicates that cob weight may be more affected by general improvements in soil conditions rather than the specific properties of the biochar. These findings are consistent with the work of [29], who found minimal effects of biochar type on certain yield traits, likely due to variations in environmental and management factors. In contrast, the application rates of biochar significantly influenced cob weight (Fig. 6 ). The highest weights were recorded at an application rate of 8 t ha⁻¹, while the lowest weights were observed in the control plots for both years. Interestingly, in 2023, cob weights at 6 t ha⁻¹ and 4 t ha⁻¹ were statistically similar to those at 8 t ha⁻¹, indicating that moderate rates of biochar can also lead to considerable improvements. These results are further supported by studies such as those by [25] and [2], which demonstrated biochar's potential to enhance crop yields through improved nutrient cycling and soil structure. 3.2.3. Grain yield The study found no significant differences in grain yield among the various types of biochar over the two years (Table 4 ). This suggests that while biochar improves soil properties and supports plant growth, the specific type of feedstock used may not be a critical factor affecting grain yield under the experimental conditions tested. Similar results have been observed in previous research, which indicates that biochar's impact on yield is more influenced by interactions between soil characteristics, crop type, and environmental factors rather than the type of biochar itself [30]. Grain yield did, however, vary significantly based on the application rates of biochar (Fig. 7 ). Higher application rates consistently resulted in increased yields compared to the control group. Specifically, the application of 8 t ha⁻¹ of biochar produced the highest grain yields, reaching 3.5 t ha⁻¹ in 2022 and 3.3 t ha⁻¹ in 2023. Conversely, the control plots yielded the lowest results, with 1.1 t ha⁻¹ in 2022 and 1.6 t ha⁻¹ in 2023. In 2022, the application of biochar at rates of 2, 4, 6, and 8 t ha⁻¹ led to yield increases of 63.6%, 100%, 136.4%, and 218.2%, respectively, compared to the control. In 2023, these application rates improved yields by 87.5%, 112.5%, 100%, and 106.3%, respectively, over the control. This demonstrates a strong correlation between increasing biochar application rates and grain yield, supporting findings from studies such as [24], which highlight biochar’s ability to enhance soil structure, nutrient retention, and moisture availability, ultimately leading to improved crop productivity. Grain yields in 2023 were generally higher than those in 2022 across most treatments. This variability can be attributed to environmental factors such as rainfall distribution, temperature differences, and other climatic conditions that influence crop growth and the effectiveness of biochar. Research by [32] emphasizes the significance of climatic factors in determining the agronomic effectiveness of biochar. Notably, the consistency in yield at the highest application rate of 8 t ha⁻¹ across both years suggests that this rate may mitigate the effects of environmental variability, providing stable benefits for maize production. These findings support previous research indicating that biochar application enhances soil fertility and productivity [33, 25]. However, the degree of improvement varies based on site-specific factors such as soil type, biochar characteristics, and crop management practices. While higher application rates resulted in the most substantial yield improvements, diminishing returns were observed beyond 8 t ha⁻¹, consistent with earlier studies [2]. 3.2.4. Hundred seed weight The results indicate that the type of biochar significantly influenced the 100-seed weight in 2022, while no significant differences were observed in 2023 (Table 4 ). In 2022, rice husk and sawdust biochar outperformed groundnut husk biochar, suggesting that the type of biochar can enhance seed weight. This improvement is likely due to variations in nutrient composition and physical properties. Specifically, rice husk and sawdust biochars may offer better nutrient release, improved soil moisture retention, or enhanced conditions for root development [24]. These findings align with previous studies that suggest the nutrient-rich composition of certain biochars can support crop productivity by improving soil health and nutrient availability [33]. The positive impact of biochar application rate on 100-seed weight is illustrated in Fig. 8 . In 2022, the highest 100-seed weight was recorded at a biochar application rate of 6 t ha⁻¹, which was statistically similar to the rates of 4 and 8 t ha⁻¹. In contrast, the control treatment consistently resulted in the lowest seed weights, highlighting the beneficial role of biochar amendments. In 2023, the maximum 100-seed weight was observed at the 8 t ha⁻¹ application rate, followed closely by the 6 and 4 t ha⁻¹ rates, which were statistically equivalent and significantly higher than the control. Furthermore, the 2 t ha⁻¹ rate performed significantly better than the unamended control. These results are consistent with the findings of [29] and [13], who reported that biochar amendments improve seed development and yield quality. Biochar's ability to enhance water retention, nutrient availability, and soil structure may explain these observed trends. Additionally, the slight variations between the years could be attributed to differences in environmental conditions, such as rainfall or temperature, which can influence crop responses to soil amendments [30]. 3.2.5. Harvest index The harvest index, which indicates how efficiently a crop allocates biomass to grain, showed no significant differences across the various types of biochar in both study years (Table 4 ). This finding suggests that while biochar may enhance overall biomass production, the specific type of biochar does not significantly affect the proportion of biomass allocated to grains. These results align with previous studies indicating that biochar primarily influences general plant growth rather than directly altering the harvest index [34]. The impact of biochar application rates on the harvest index, illustrated in Fig. 9 , revealed no significant differences during the first year. However, in the second year, biochar-treated plots showed a notable increase in the harvest index compared to the control. This trend supports evidence that the benefits of biochar application often become more pronounced over time as it integrates into the soil, improving critical properties such as nutrient retention, microbial activity, and water-holding capacity [35, 2]. The gradual improvement observed in this study may result from the slower nature of biochar's effects. Biochar's interaction with soil particles and organic matter enhances cation exchange capacity (CEC) and nutrient retention, processes that take time to stabilize and fully develop [33,36]. Specifically, the increase in the harvest index during the second year suggests that biochar's cumulative effects significantly enhance grain yields relative to biomass production. These findings are consistent with [37], who noted that biochar's impact on crop productivity tends to intensify in the growing seasons following its application. Biochar's ability to enhance soil fertility by improving nutrient availability, soil structure, and water retention likely contributed to the observed increase in the harvest index [45]. Environmental factors, such as variations in rainfall and temperature, may also account for the differing impacts of biochar across years, as these conditions influence the rate at which biochar interacts with soil processes [50]. The benefits of biochar on crop yield may have been increased in the second year due to more favourable conditions for interactions between the biochar and the soil. Table 4 The effect of biochar type on the cob weight, grain yield 100-seed weight, and harvest index of maize grown during the 2022 and 2023 cropping seasons. Biochar type Cob weight (t/ha) Grain yield (t/ha) 100-seed weight (g) Harvest index (%) Cropping season 2022 2023 2022 2023 2022 2023 2022 2023 Rice husk 2.7a † 3.3a 2.2a 2.8a 27.5a 23.8a 0.81a 0.9a Groundnut 2.8a 3.2a 2.4a 2.9a 27.1b 25.0a 0.84a 0.9a Saw dust 2.6a 3.4a 2.2a 2.9a 27.6a 25.4a 0.81a 0.9a LSD (5%) 0.28 0.28 0.29 0.26 0.37 1.64 0.061 0.05 CV 13.20 10.8 16.8 11.7 1.7 8.6 9.5 6.70 † Values with the same lowercase letters in a column in the year are not significantly different at p < .05. Table 4 near here Figure 6 near here Figure 7 near here Figure 8 near here Figure 9 near here 3.3. Soil Chemical properties 3.3.1. Soil pH and organic matter The influence of biochar on soil pH differed significantly between 2022 and 2023 (Table 5 ). In 2022, there was no substantial variation in soil pH among the three types of biochar. However, in 2023, notable differences were observed. Both rice husk and groundnut husk biochar treatments produced similar pH values, which differed significantly from those recorded with sawdust biochar. The application rates of biochar had a pronounced effect on soil pH (Table 5 ). The highest pH values consistently occurred at the 8 t ha⁻¹ application rate. In 2022, nitrogen concentrations increased with biochar application rates of 2, 4, 6, and 8 t ha⁻¹, resulting in pH increases of 6.7%, 13.2%, 15.0%, and 17.6%, respectively, compared to the control. In 2023, the corresponding pH increases were even more pronounced, rising by 10.1%, 16.4%, 21.5%, and 26.0% over the control. These observed pH increases with biochar application agree with findings by [39] and [40], which indicated that the alkalinity of biochar often enhances soil pH. This enhancement is attributed to biochar's ability to neutralize soil acidity and improve buffering capacity, especially in acidic soils. The higher pH levels observed in 2023 suggest cumulative effects, indicating that biochar can integrate with soil properties over time, leading to sustained improvements. Notably, the type of biochar did not significantly influence soil organic matter (SOM) in either year. This suggests that while biochar application typically increases SOM, the specific feedstock used to produce the biochar may not play a decisive role in short-term SOM enhancement. This finding is consistent with [29], who reported that biochar increases soil organic carbon (SOC), a major component of SOM, irrespective of feedstock type. The uniform effect of biochar across different types may be attributed to its inherent carbon content and its role in stabilizing existing organic matter in the soil. [34] pointed out that the long-term effects of biochar on SOM depend more on its stability in the soil than on the specific feedstock used. However, [45] suggested that variations in feedstock might produce distinct effects over extended periods or under different environmental conditions, particularly if the biochar contains varying nutrient levels. The rate of biochar application significantly impacted SOM levels, with the highest increases observed at the 8 t ha⁻¹ application rate. In 2022, SOM increased by 89.6%, 188.0%, 234.4%, and 343.4% for application rates of 2, 4, 6, and 8 t ha⁻¹, respectively, compared to the control. A similar trend was observed in 2023, with SOM increasing by 93.4%, 206.6%, 284.6%, and 343.4% at the same application rates. These results underscore the effectiveness of higher biochar application rates in enhancing SOM levels. This aligns with the findings of [33], who noted that biochar enhances SOM by adding stable carbon and improving soil structure. Furthermore, [39] found that biochar’s impact on SOM could vary based on soil type, climate, and management practices—factors that may overshadow the influence of biochar feedstock in short-term studies. The study demonstrates that biochar application improves soil pH and SOM, with these effects amplified at higher application rates. However, the type of biochar appears less critical in short-term enhancements. These findings reinforce the importance of biochar application rates as a determinant of its agronomic benefits and highlight its potential for improving soil health over time. 3.3.2. N, P, and K The type of biochar significantly influenced soil nitrogen (N) concentrations in both years of the study (Table 5 ). In 2022, rice husk and groundnut husk biochar resulted in comparable nitrogen levels, both significantly higher than those observed with sawdust biochar. This trend persisted in 2023, with groundnut husk biochar consistently outperforming the others in enhancing nitrogen levels. The observed increase in soil N aligns with [29], who highlighted biochar's role in improving nitrogen retention and availability due to its high surface area and cation exchange capacity (CEC). Nitrogen concentrations increased progressively with higher biochar application rates (Table 5 ). For instance, in 2022, biochar application at 2, 4, 6, and 8 t ha⁻¹ led to nitrogen increases of 70%, 140%, 190%, and 220%, respectively, over the control. In 2023, the corresponding increases were 30%, 55%, 70%, and 100%. These findings demonstrate biochar's dose-dependent effect, corroborating [25], who reported that higher biochar rates improve nutrient availability by enhancing microbial activity and reducing nutrient losses. The cumulative nitrogen improvement over time can be attributed to biochar's long-term stability and its gradual nutrient release [43]. Variability in nitrogen improvements between years might reflect climatic conditions or initial soil characteristics, as suggested by [37], who emphasized that biochar's efficacy depends on environmental factors. Biochar type significantly influenced soil phosphorus (P) levels during both years (Table 5 ). In 2022, rice husk and groundnut husk biochar produced similar P levels, both higher than sawdust biochar. However, in 2023, groundnut husk biochar showed the highest P concentrations, while rice husk and sawdust biochar were statistically equivalent. These findings are consistent with [26], who noted that differences in biochar feedstock composition can influence nutrient release dynamics. Phosphorus levels increased markedly with higher biochar application rates (Table 5 ). In 2022, biochar applied at 2, 4, 6, and 8 t ha⁻¹ raised P levels by 23.8%, 37.9%, 42.5%, and 60.4%, respectively, compared to the control. In 2023, the increases were more pronounced at 44.7%, 53.8%, 59.3%, and 81.3%. The ability of biochar to enhance soil P can be attributed to its capacity for nutrient adsorption and gradual release, as reported by [45]. [46] also highlighted biochar’s potential to reduce nutrient leaching and improve plant-available P, particularly in nutrient-deficient soils. Soil potassium (K) levels were significantly influenced by both biochar type and application rate across the study (Table 5 ). In 2022, sawdust biochar recorded the highest soil K concentrations, while in 2023, rice husk and groundnut husk biochar showed comparable K levels, both higher than those obtained with sawdust biochar. These differences can be attributed to the mineral composition and nutrient release characteristics of the biochars, as noted by [41]. Potassium levels consistently increased with higher biochar application rates (Table 5 ). In 2022, soil K rose by 161.5%, 253.8%, 307.7%, and 377.0% at 2, 4, 6, and 8 t ha⁻¹, respectively, over the control. In 2023, the corresponding increases were 100.0%, 181.3%, 253.8%, and 306.3%. These findings are consistent with [46], who emphasized biochar’s effectiveness in retaining and gradually releasing potassium, especially at higher application rates. The results demonstrate that biochar type and application rate significantly affect soil nutrient levels (Table 5 ). Groundnut husk biochar exhibited superior performance in improving soil nitrogen and phosphorus levels, while sawdust biochar was more effective for potassium enhancement. Higher application rates consistently produced better results, emphasizing the importance of biochar dose in soil fertility management (Table 5 ). These findings underscore biochar’s potential as a sustainable soil amendment to enhance nutrient availability, especially in nutrient-deficient soils. Future research should investigate long-term effects and interactions with varying environmental conditions to optimize biochar use in agricultural systems. Table 5 The effect of biochar type and rate on the soil pH, Organic matter, N, P, and K after harvesting during the 2022 and 2023 cropping seasons Biochar pH (1:2.5 H 2 O) OM (%) N (%) P (mg/kg) K (mg/kg) Year 2022 2023 2022 2023 2022 2023 2022 2023 2022 2023 Type (T) Rice husk 5.61a † 5.80a 3.56a 3.93a 0.23a 0.30a 42.85a 48.71b 0.40b 0.44a Groundnut husk 5.66a 5.67a 3.20a 3.98a 0.23a 0.26b 44.39a 53.13a 0.40b 0.44a Sawdust 5.51a 5.51b 3.40a 3.75a 0.19b 0.30a 38.03b 46.92b 0.46a 0.40b LSD (5%) 0.15 0.15 0.38 0.38 0.02 0.02 3.93 4.64 0.03 0.03 Rate (R) 0 5.06d 4.93e 1.25e 1.36e 0.10e 0.20d 31.43d 33.54c 0.13e 0.16e 2 5.40c 5.43d 2.37d 2.63d 0.17d 0.26c 38.90c 48.54b 0.34d 0.32d 4 5.73b 5.74c 3.60c 4.17c 0.24c 0.31b 43.27bc 51.59b 0.46c 0.45c 6 5.82ab 5.99b 4.18b 5.23b 0.29b 0.31b 44.78b 53.44b 0.53b 0.55b 8 5.95a 6.21a 5.54a 6.03a 0.32a 0.34a 50.42a 60.82a 0.62a 0.65a LSD (5%) 0.20 0.19 0.49 0.49 0.03 0.02 5.08 6.00 0.03 0.04 (T x R) NS NS NS NS NS 0.035 NS NS NS NS CV 3.50 3.50 14.50 12.5 12.20 7.50 12.20 12.10 7.70 9.30 † Values with the same lowercase letters in a column in the year are not significantly different at p < .05. NS; Not significant. Table 5 near here 4. Relationship between maize parameters and Soil chemical properties The correlation analysis highlights the positive impact of biochar application on maize yield and its association with soil chemical properties, providing valuable insights into biochar's role as a soil amendment (Tables 6 & 7 ). The strong and positive correlations between yield parameters (such as plant height, cob weight, grain yield, and 100-seed weight) and soil properties (pH, organic matter, nitrogen, phosphorus, and potassium) emphasize the role of biochar in enhancing soil fertility and crop productivity. This agrees with findings from [46], who detailed biochar's potential to improve soil chemical properties by increasing nutrient availability, enhancing soil organic matter stability, and buffering soil pH. Nitrogen showed a consistent and significant correlation with maize yield, underscoring its essential role in crop productivity. The increase in soil nitrogen availability through biochar application is supported by [47], who observed that biochar enhances nitrogen retention by reducing leaching and increasing the soil's cation exchange capacity (CEC). This is particularly critical for tropical soils, where nutrient losses are high due to leaching and volatilization. The significant association between soil phosphorus and yield-related traits highlights biochar's role in nutrient cycling and microbial activity enhancement. Biochar contributes to phosphorus availability through sorption-desorption dynamics and interactions with soil microbes [6]. Furthermore, the positive relationship between organic matter and yield aligns with findings that biochar enhances soil structure, water retention, and microbial biomass, all of which contribute to better crop growth [48]. The lack of a significant relationship between the harvest index and soil properties, except for 100-seed weight, suggests that this trait may be influenced by factors beyond soil fertility, such as genotypic differences, climatic conditions, and crop management practices. [30] noted that the harvest index might not be as responsive to soil amendments as other yield parameters, emphasizing the need to consider additional physiological and environmental factors in its assessment. Table 6 Correlation coefficient matrix for parameters during the 2022 season Variable PH SW CN CW GY 100-SW HI pH OM N P K Plant height 1.000 Stalk weight 0.71*** 1.000 Cob number 0.68*** 0.87*** 1.000 Cob weight 0.73*** 0.98*** 0.88*** 1.000 Grain yield 0.71*** 1.000*** 0.87*** 0.98*** 1.000 100 seed weight 0.52*** 0.63*** 0.66*** 0.63*** 0.63*** 1.000 Harvest index 0.03 0.27 0.19 0.08 0.27 0.08 1.000 pH 0.63*** 0.66*** 0.68*** 0.67*** 0.66*** 0.53*** 0.10 1.000 Organic matter 0.73*** 0.83*** 0.82*** 0.83*** 0.83*** 0.71*** 0.15 0.63*** 1.000 N 0.66*** 0.85*** 0.84*** 0.85*** 0.85*** 0.64*** 0.18 0.69*** 0.85*** 1.000 P 0.60*** 0.69*** 0.63*** 0.70*** 0.69*** 0.58*** 0.09 0.73 0.65*** 0.72*** 1.000 K 0.68*** 0.80*** 0.88*** 0.79*** 0.80*** 0.72*** 0.25 0.68*** 0.88*** 0.83*** 0.589*** ( - ) not significant, ( * ) significant at p < 0.05, ( ** ) significant at p < 0.01, (***) significant at p < 0.001 Table 7 Correlation coefficient matrix for parameters during the 2023 Season Variable PH SW CN CW GY 100-SW HI pH OM N P K Plant height 1.000 Stalk weight 0.60*** 1.000 Cob number 0.45** 0.60*** 1.000 Cob weight 0.52*** 0.62*** 0.61*** 1.000 Grain yield 0.61*** 0.96*** 0.62*** 0.590*** 1.000 100-seed weight 0.28 0.29 0.33* 0.23 0.32* 1.000 Harvest index 0.22 0.53*** 0.17 -0.28 0.60*** 0.18 1.000 pH 0.40* 0.51*** 0.62*** 0.72*** 0.54*** 0.26 -0.07 1.000 Organic matter 0.53*** 0.56*** 0.68*** 0.66*** 0.62*** 0.27 0.07 0.82*** 1.000 N 0.38* 0.62*** 0.72*** 0.38* 0.68*** 0.38* 0.46** 0.50*** 0.64*** 1.000 P 0.42** 0.47** 0.50*** 0.63*** 0.52*** 0.25 -0.01 0.72*** 0.72*** 0.38* 1.000 K 0.57*** 0.59*** 0.65*** 0.73*** 0.64*** 0.27 0.03 0.86*** 0.93*** 0.63*** 0.76*** ( - ) not significant, ( * ) significant at p < 0.05, ( ** ) significant at p < 0.01, (***) significant at p < 0.001 Table 6 near here Table 7 near here 5. Conclusion This study, titled Biochar Types Effects on Soil Properties and Yield of Maize in Northern Region, Ghana demonstrates the potential of biochar as a sustainable soil amendment for improving soil fertility and maize yields in tropical agroecosystems. The findings underscore the importance of biochar type, application rate, and environmental conditions in determining its effectiveness. Groundnut husk biochar consistently exhibited superior performance in enhancing key soil nutrients such as nitrogen and phosphorus, while sawdust biochar excelled in improving potassium levels. This differentiation highlights the need for feedstock-specific recommendations to optimize biochar applications for nutrient-deficient soils. Higher biochar application rates (6–8 t ha⁻¹) were shown to be optimal for improving critical yield parameters, including grain yield, 100-seed weight, and stalk weight, without diminishing returns. The study also highlights the role of biochar in sustaining long-term productivity by enhancing soil organic matter, pH, and nutrient retention, with the most significant improvements observed under the highest application rates. The strong positive correlations between soil fertility indicators and maize yield components reaffirm biochar's multifaceted benefits in promoting sustainable agricultural practices. This research is novel in integrating biochar’s specific feedstock effects, optimal application rates, and multi-year data to provide actionable insights for scaling its use in tropical agriculture. While the immediate effects on some yield parameters, like the harvest index, were modest, the cumulative benefits underline biochar's potential as a long-term investment in soil health and crop productivity. Future research should explore biochar's interactions with other soil amendments and its impacts under varying environmental conditions to refine its use across diverse agroecological systems. These insights serve as a foundation for leveraging biochar to address soil fertility challenges sustainably in Northern Ghana and beyond. Declarations Acknowledgements: This work was conducted at the Savanna Agricultural Research Institute. We are thankful for the support of the management team. We also appreciate Mr. Alhassan Yamyolya Baako for monitoring and collecting data in the field. Authors contributions: All authors reviewed the manuscript Author contribution ALAA: conceptualization, investigation, data collection, methodology, data analysis, and full writeup. IAA, MMG, AH, MA and RA: Conceptualization, investigation, writing review, supervision, and editing. All authors read and approved the final manuscript. Declaration of competing interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Consent to Publish Declaration: Verbal informed consent was obtained from all participants after they were fully briefed on the study's objectives, methodology, data collection procedures, and their rights, including the option to withdraw at any time without consequences. The corresponding author, affiliated with the CSIR-Savanna Agricultural Research Institute, is duly authorized to conduct the field experiments and data collection. All ethical guidelines established by the CSIR-Savanna Agricultural Research Institute for research, data collection, and analysis were strictly followed to ensure compliance with institutional and ethical standards. Consent to Participate declaration: not applicable. 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distribution recorded during the 2022 and 2023 seasons.\u003c/p\u003e\n\u003cp\u003eSource: SARI Agrometeorological station reports, 2023.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/8ac64d5e5419985556df7519.png"},{"id":81307579,"identity":"241a75fe-c66e-4d52-b17a-ff7cd57cc3bb","added_by":"auto","created_at":"2025-04-24 14:54:54","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":22337,"visible":true,"origin":"","legend":"\u003cp\u003eTemperature distribution recorded during the 2022 and 2023 seasons\u003c/p\u003e\n\u003cp\u003eSource: SARI Agrometeorological station reports, 2023.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/5c69e426ecf20e8f5226c71c.png"},{"id":81307581,"identity":"278381ab-1302-4ce9-a5bb-c4155f087171","added_by":"auto","created_at":"2025-04-24 14:54:54","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":13977,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of biochar rate on the plant height of maize grown during the 2022 and 2023 cropping seasons.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/e5e6ccaa5daa85507e009c78.png"},{"id":81307583,"identity":"4f359a4c-3c2a-4a9d-b1a0-47a103d072a8","added_by":"auto","created_at":"2025-04-24 14:54:54","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":13438,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of biochar rate on the stover weight of maize grown during the 2022 and 2023 cropping seasons.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/b4bb475d705d40daf190f2c2.png"},{"id":81308232,"identity":"ffd354d3-79ab-4927-a61f-93c8ef2f2777","added_by":"auto","created_at":"2025-04-24 15:02:54","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":13467,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of biochar rate on the cob number of maize grown during the 2022 and 2023 cropping seasons.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/e47961d22e24c7e9d80c4a38.png"},{"id":81308234,"identity":"91bfd58e-94c0-4b22-907b-f8b3a51e1bdc","added_by":"auto","created_at":"2025-04-24 15:02:54","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":13473,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of biochar rate on the cob weight of maize grown during the 2022 and 2023 cropping seasons.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/a5bd98e1b527f9099ef8ab06.png"},{"id":81308231,"identity":"e383d219-b870-4278-a890-37fd31dee3f3","added_by":"auto","created_at":"2025-04-24 15:02:54","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":12713,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of biochar rate on the grain yield of maize cultivated during the 2022 and 2023 cropping seasons.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/840022036abf956730ef2def.png"},{"id":81307594,"identity":"6770b59c-cd36-4638-8cd5-59cddb917210","added_by":"auto","created_at":"2025-04-24 14:54:55","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":12676,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of biochar rate on the 100-seed weight of maize cultivated during the 2022 and 2023 cropping seasons.\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/2b473ff911ba81b3f7099f95.png"},{"id":81307590,"identity":"326b1ae4-504d-49a5-add9-209ba6a896c7","added_by":"auto","created_at":"2025-04-24 14:54:54","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":13850,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of biochar rate on the harvest index of maize grown during the 2022 and 2023 cropping seasons.\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/d2a56e691262eecc5ee122e6.png"},{"id":81704116,"identity":"ae3a2c50-168e-4bcd-a377-7fbf0ed7dfa3","added_by":"auto","created_at":"2025-04-30 13:15:13","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1538658,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6127479/v1/220b66ef-9429-4aab-b144-1c98d56bfc2a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Biochar Effects on Soil Properties and Yield of Maize in Northern Region, Ghana","fulltext":[{"header":"Highlights","content":"\u003cul class=\"decimal_type\"\u003e\n \u003cli\u003eThe application of biochar significantly improved soil pH, organic matter content, and nutrient availability, leading to enhanced overall soil health.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eApplying biochar at a rate of 8 tons per hectare resulted in the highest maize grain yield, with increases of up to 218.2% in 2022 and 106.3% in 2023.\u003c/li\u003e\n \u003cli\u003eBiochar from groundnut husks outperformed rice husk and sawdust biochar in enhancing soil fertility and maize yield.\u003c/li\u003e\n \u003cli\u003eThis study confirmed that biochar is an effective and sustainable soil amendment, especially at higher application rates.\u003c/li\u003e\n \u003cli\u003eA strong positive relationship was established between maize yield and the improved chemical properties of the soil, except the harvest index, underscoring biochar\u0026apos;s potential to boost agricultural productivity.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"1. Introduction","content":"\u003cp\u003eBiochar is a carbon-rich material created through biomass pyrolysis in oxygen-limited conditions. It has gained considerable attention as a sustainable solution for improving soil health, enhancing agricultural productivity, and mitigating climate change. Its ability to enhance soil structure, nutrient retention, and water-holding capacity is particularly vital for resource-constrained farming systems [1,2]. These properties are essential for maize (Zea mays L.), a staple crop widely cultivated in tropical and subtropical regions where soil fertility often poses a challenge [3,4]. Recent advancements in biochar production technologies have significantly increased the material's adaptability and effectiveness for agricultural applications. Modern pyrolysis techniques, such as continuous-feed reactors and gasification systems, enable precise control over temperature and heating rates, allowing for the tailoring of biochar's physicochemical properties to meet specific agricultural needs [5,6]. Additionally, artisanal and low-cost pyrolysis methods, specifically designed for smallholder farmers in resource-limited settings, provide a practical way to convert locally available biomass into biochar, increasing accessibility [7]. The effectiveness of biochar is largely influenced by the characteristics of its feedstock, pyrolysis conditions, and application rates. Feedstocks such as woody biomass produce biochar with high porosity and stable carbon content, which is ideal for improving soil aeration and creating favourable conditions for microbial life [8]. In contrast, biochar from agricultural residues, such as maize stalks and banana peels, tends to be richer in nutrients, thereby enhancing soil fertility directly [8,9]. Emerging research has highlighted the significance of feedstock-specific innovations, indicating that biochar's nutrient release patterns and carbon stability can vary considerably across different biomass types [10,11]. Moreover, studies indicate that the application rate of biochar plays a crucial role in determining its impact on crop productivity. Moderate application rates (e.g., 5\u0026ndash;10 tons/ha) consistently improve soil fertility and crop yields, while excessive rates can disrupt soil nutrient balance or pH, leading to diminished returns [12,13]. In maize production systems, biochar has shown variable yield responses depending on soil fertility levels. In acidic and nutrient-poor soils, the application of biochar often leads to significant yield increases, whereas the benefits are less noticeable in fertile soils [14,15]. In Ghana and other semi-arid regions, biochar made from crop residues has demonstrated promise in improving nitrogen use efficiency and enhancing soil organic matter, thereby contributing to sustainable maize production under challenging conditions [16]. Despite these findings, gaps remain in understanding how biochar properties, application rates, and specific soil-crop systems interact, particularly in smallholder farming contexts. This study aims to investigate the effects of different biochar types and application rates on soil properties and maize productivity. By evaluating biochars produced from various feedstocks and applied at different rates, the research seeks to provide practical recommendations for optimising biochar use in maize farming systems, ultimately enhancing soil health, crop productivity, and environmental sustainability.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Experimental area\u003c/h2\u003e \u003cp\u003eThe experiment was carried out at the research field of Savannah Agriculture Research Institute (SARI) in the Tolon District of Northern Ghana. The site is situated in the Guinea Savannah Agroecological Zone, between 9\u0026deg; 25\u0026prime; N and 00\u0026deg; 58\u0026prime; W. The rainfall pattern is unimodal, occurring from May to October, with peaks in August and September. The average annual rainfall is 93.9 mm, and the season lasts six months, mostly from April to September. The area is further identified by a long dry season (4\u0026ndash;6 months), typically from November to April. Throughout the growth season, there are intermittent dry spells that can last up to 2\u0026ndash;4 weeks. Temperatures are highest from March to April, and lowest in December due to north-east trade winds pushing the Inter Tropical Convergence Zone further south. The average monthly minimum and maximum temperatures are 26.6\u0026deg;C and 35.6\u0026deg;C, respectively, while the average yearly temperature is 29.7\u0026deg;C [17]. The rainfall and temperature patterns monitored at Nyankpala from January to December during the 2022 and 2023 cropping seasons are shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e near here\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e near here\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Soil sampling, preparation and analysis\u003c/h2\u003e \u003cp\u003eSoil samples were collected before and after the experiment from different replicate plots. Before the experiment, five soil cores were taken from each replicate plot at 0\u0026ndash;15 cm depth. These core samples were combined to form a composite sample. After the experiment, additional soil samples were obtained from each plot. The collected soil samples were air-dried and passed through a 2-mm mesh sieve. This sieving process ensured that the soil particles were of consistent size for further analysis. Particle size analysis was conducted using the hydrometer method, as described by [18]. Fifty grams of the sampled soil were weighed and used in the analysis to determine the distribution of different particle sizes in the soil. Soil pH was measured by preparing a suspension of 10 grams of soil in 25 ml of water. The pH of this suspension was then determined using a pH meter. The soil organic carbon content was determined using the method described by [19]. A 0.5-gram portion of the soil sample was weighed and used in this analysis. The total nitrogen content of the soil was determined using the Kjeldahl method. One gram of the sampled soil was weighed and used for this analysis. Available phosphorus in the soil was determined using the Bray 1 method, as described by [20]. Again, one gram of the soil sample was weighed and used for this analysis. Cation Exchange Capacity (CEC) was determined by leaching ten grams of the sampled soil with neutral 1M ammonium acetate, following the guidelines provided by [21]. These standardized laboratory procedures were followed to ensure accurate and consistent analysis of the soil samples.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Soil characteristics\u003c/h2\u003e \u003cp\u003eThe result of the analysis is evident of common characteristics of savanna soil as the experimental site is sand silt in texture and slightly acidic in reaction (pH 5.5\u0026ndash;6.5) with a very low organic carbon content (\u0026lt;\u0026thinsp;20 g/kg) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), Total nitrogen and exchangeable cations were less than 1g/kg and 5 cmol(+)/kg) respectively with available P being less than 10 mg/kg [22](Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePhysico-chemical characteristics of the soil at horizon 0\u0026ndash;15 cm.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTest value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSand (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61.88\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSilt (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e32.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClay (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTexture\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSandy silt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epH (1:2.5 H\u003csub\u003e2\u003c/sub\u003eO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO.C (g /kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.93\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN (g /kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP (mg/kg)\u003c/p\u003e \u003cp\u003eExchangeable cations (cmol(+)/kg):\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNa\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCa\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.60\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e near here\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Biochar preparation\u003c/h2\u003e \u003cp\u003eFarm and municipal waste (rice husk, groundnut husk, and sawdust) generated in the farmer fields and sawmills were collected and charred to obtain biochar. The biochar was produced in a fabricated drum pyrolysis unit with a nominal peak temperature of 500\u0026deg;C. The rice husk, ground nut husk, and sawdust were all crushed and then passed through a 2 mm filter. The resulting biochar types were stored for chemical analysis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5. Biochar characteristics\u003c/h2\u003e \u003cp\u003eThe pH of ground air-dried rice husk, groundnut husk, and sawdust biochar materials was measured in water and 0.01M CaCl\u003csub\u003e2\u003c/sub\u003e at a biochar to liquid ratio of 1:10. The carbon and nitrogen contents were determined using a Leco Trumac Carbon Nitrogen Sulphur version 1.3 Analyzer. Water soluble and then ammonium extractable bases (Ca, Mg, K, and Na) in biochar types were extracted progressively with de-ionized water and 1M ammonium acetate, and the concentrations were measured using a Perkin Elmer Analyst 800 Atomic Absorption Spectrometer. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the chemical composition of the biochar (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe chemical composition of biochar derived from rice husk, groundnut husk, and sawdust\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFeedstock type\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003epH H\u003csub\u003e2\u003c/sub\u003eO (1:2.5)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e% N\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFixed C\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC/N ratio\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eAvail. P (mg/kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eCa (mg/kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eMg (mg/kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eK (mg/kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNa (mg/kg)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRice husk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e142\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e129\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e144\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e208.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e304.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e303.47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroundnut\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e58.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e42.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1300\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e152\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e7500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e6200\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSawdust\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e11.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e492\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e165.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e440.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e416.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e near here\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.6. Experimental design\u003c/h2\u003e \u003cp\u003eThree agricultural waste materials (rice husk, groundnut husk and sawdust) produced as biochar were evaluated under 5 application rates for improved grain yield, yield components and soil characteristics during the 2022 and 2023 cropping seasons under field experimental conditions. The treatment consisted of 2 factors, namely, 3 biochar (rice husk, groundnut and sawdust) and 5 levels of biochar application rates (0, 2, 4, 6, and 8 t ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). The whole plot area used was 4 m x 20 m with 2 m alley each between whole plots and replicates. Each subplot measured 4 m x 4 m with 1 m alley between them. The biochar was applied to the soil by broadcasting and manually incorporated into the soil with a hoe to a depth of approximately 15 cm. The Wandaata maize variety was used as the test crop. Three seeds were planted per stand, which was later thinned to two after two weeks from planting using a planting distance of 80 cm x 40 cm. A blank basal application of NPK 14:18:18 was done across plots, including the control. Weeding of the field was done on the second, fifth, and eighth weeks after planting.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e2.7. Statistical analysis\u003c/h2\u003e \u003cp\u003eThe data collected were subjected to ANOVA using GenStat statistical software, and the test treatments were differentiated using the Least Significant Differences at a 5% probability level.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003e3.1. Growth parameters\u003c/h2\u003e\n \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\n \u003ch2\u003e3.1.1. Plant height\u003c/h2\u003e\n \u003cp\u003eThe impact of various types of biochar on plant height was evaluated over two growing seasons (refer to Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). In 2023, no significant differences in plant height were observed among the different biochar types, indicating uniform effects on vertical growth for that year. However, results from 2022 showed that plants treated with groundnut husk biochar achieved the greatest height, measuring 149 cm. This suggests that groundnut husk biochar may possess unique properties, such as high nutrient content or effective soil conditioning, that promote enhanced vegetative growth. Previous studies support these findings, indicating that biochar can improve plant growth through mechanisms such as increased nutrient availability, improved water retention, and enhanced soil structure [24, 25]. Figure \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e illustrates the effect of different biochar application rates on plant height over the two years. In 2023, all application rates resulted in significant increases in plant height compared to the control group, with higher rates (6\u0026ndash;8 t ha\u003csup\u003e-1\u003c/sup\u003e) producing the most substantial improvements. In contrast, only application rates of 4 t/ha and above led to significant differences in plant height in 2022. These variations may be attributed to differences in weather conditions or the cumulative effects of biochar over time. Biochar\u0026apos;s ability to retain nutrients and enhance microbial activity may strengthen with prolonged use [38, 26]. Notably, plants treated with 2 t/ha of biochar experienced a significant increase in height in 2023 compared to 2022. This inter-annual difference may reflect the gradual enhancement of soil fertility by biochar, as seen in other studies where biochar\u0026apos;s benefits grew over time due to improved soil organic matter and microbial interactions [16, 27]. These findings highlight the potential of biochar as a sustainable soil amendment for enhancing crop growth. However, the effects of biochar appear to be influenced by the application rate, type of biochar, and environmental conditions. In particular, groundnut husk biochar seems to be a promising option, likely due to its higher rates of nutrient release and favourable interactions with the soil. These results are consistent with reports indicating that biochars derived from agricultural residues often outperform those derived from forestry residues in terms of nutrient availability [9, 17].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e\n \u003ch2\u003e3.1.2. Stalk weight\u003c/h2\u003e\n \u003cp\u003eThe analysis indicated that stalk weight did not vary significantly across different types of biochar in either year (Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). This consistency suggests that the contribution of biochar to stalk biomass production relies more on its general soil amelioration properties than on its specific type. Previous studies support this observation, highlighting that the impact of biochar on plant biomass is often linked to its ability to enhance soil properties, such as nutrient availability and water retention, rather than unique chemical characteristics associated with particular biochar types [28]. Figure \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003eillustrates the influence of biochar application rates on stalk weight. A clear trend emerged where higher biochar application rates resulted in significant increases in stalk weight across both years. In 2022, stalk weights reached a peak of 3.5 t ha⁻\u0026sup1; for the 8 t ha⁻\u0026sup1; application rate, while the control group recorded the lowest stalk weight at 1.1 t ha⁻\u0026sup1;. Similar patterns were observed in 2023, with the highest and lowest stalk weights corresponding to the 8 t ha⁻\u0026sup1; and control treatments, respectively (3.5 t ha⁻\u0026sup1; and 2.0 t ha⁻\u0026sup1;). These findings align with earlier studies, such as those by [24], which reported that biochar improves nutrient retention and soil structure, ultimately leading to increased plant biomass production. Notably, stalk weights across all treatments in 2023 exceeded those of 2022, except for the 8 t ha⁻\u0026sup1; application rate, which remained consistent across both years. This suggests that the cumulative effects of biochar, including enhanced microbial activity, increased organic matter, and improved soil fertility, may have contributed to the higher biomass observed in 2023 [15,29]. The plateau observed at the 8 t ha⁻\u0026sup1; application rate further indicates that this level may represent an optimal threshold under the study\u0026apos;s conditions. Beyond this point, additional biochar may yield diminishing returns, a phenomenon noted in other studies [30]. Overall, the study emphasizes the potential of biochar as a sustainable soil amendment for increasing stalk weight, particularly at higher application rates.\u003c/p\u003e\n \u003ctable border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 3\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eThe effect of biochar type on the plant height, stalk weight, and number of cobs of maize grown during the 2022 and 2023 cropping seasons\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"3\"\u003e\n \u003cp\u003eBiochar type\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003ePlant height (cm)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eStalk weight (t/ha)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eCob count (No/plot)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eCropping season\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRice husk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e142b\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e150a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.2a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.1a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e75.6a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e59.4a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGroundnut husk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e149a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e144a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.3a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74.4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e63.5b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSaw dust\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e141b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e148a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.2a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.2a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e77.9a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e63.7b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLsd (5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.71\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\"\u003e\u003csup\u003e\u0026dagger;\u003c/sup\u003eValues with the same lowercase letters in a column in the year are not significantly different at p\u0026thinsp;\u0026lt;\u0026thinsp;.05.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003cp\u003eTable \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e near here\u003c/p\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e near here\u003c/p\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e near here\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003e3.2. Yield components of maize\u003c/h2\u003e\n \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e\n \u003ch2\u003e3.2.1. Cob number\u003c/h2\u003e\n \u003cp\u003eThe number of cobs per plant showed significant variability between 2022 and 2023, particularly in response to biochar application (Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). In 2023, rice husk biochar produced the highest number of cobs per plant, unlike in 2022, when no significant differences were observed among treatments. This finding suggests that rice husk biochar may offer specific advantages for maize reproductive traits, possibly due to its nutrient profile or effects on soil properties. This observation aligns with the findings of [30], who demonstrated biochar\u0026apos;s potential to improve soil fertility and enhance plant productivity. Across both years, significant differences in cob number were observed based on the rate of biochar application (Fig. \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). The highest numbers of cobs consistently occurred at the 8 t ha⁻\u0026sup1; application rate, while the control plots exhibited the lowest numbers. This underscores the effectiveness of biochar in enhancing soil health and crop productivity through improved nutrient retention and soil structure, as noted [24]. Notably, the increase in cob number over time reflects the cumulative effects of biochar, with enhanced soil properties contributing to better performance in the second year. Similarly, [15] and [29] highlighted the long-term benefits of biochar on soil health and crop productivity. Interestingly, the unamended control showed similar cob numbers in both years, reinforcing that the observed increases are primarily due to biochar application. The consistent performance of the 8 t ha⁻\u0026sup1; rate suggests it may be an optimal dosage under the study conditions, as diminishing returns beyond certain application rates have been observed in other studies [31].\u003c/p\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e near here\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\n \u003ch2\u003e3.2.2. Cob weight\u003c/h2\u003e\n \u003cp\u003eThe type of biochar used had a negligible impact on cob weight over both years, as no significant differences were noted (Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). This indicates that cob weight may be more affected by general improvements in soil conditions rather than the specific properties of the biochar. These findings are consistent with the work of [29], who found minimal effects of biochar type on certain yield traits, likely due to variations in environmental and management factors. In contrast, the application rates of biochar significantly influenced cob weight (Fig. \u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e). The highest weights were recorded at an application rate of 8 t ha⁻\u0026sup1;, while the lowest weights were observed in the control plots for both years. Interestingly, in 2023, cob weights at 6 t ha⁻\u0026sup1; and 4 t ha⁻\u0026sup1; were statistically similar to those at 8 t ha⁻\u0026sup1;, indicating that moderate rates of biochar can also lead to considerable improvements. These results are further supported by studies such as those by [25] and [2], which demonstrated biochar\u0026apos;s potential to enhance crop yields through improved nutrient cycling and soil structure.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec17\" class=\"Section3\"\u003e\n \u003ch2\u003e3.2.3. Grain yield\u003c/h2\u003e\n \u003cp\u003eThe study found no significant differences in grain yield among the various types of biochar over the two years (Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). This suggests that while biochar improves soil properties and supports plant growth, the specific type of feedstock used may not be a critical factor affecting grain yield under the experimental conditions tested. Similar results have been observed in previous research, which indicates that biochar\u0026apos;s impact on yield is more influenced by interactions between soil characteristics, crop type, and environmental factors rather than the type of biochar itself [30]. Grain yield did, however, vary significantly based on the application rates of biochar (Fig. \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e). Higher application rates consistently resulted in increased yields compared to the control group. Specifically, the application of 8 t ha⁻\u0026sup1; of biochar produced the highest grain yields, reaching 3.5 t ha⁻\u0026sup1; in 2022 and 3.3 t ha⁻\u0026sup1; in 2023. Conversely, the control plots yielded the lowest results, with 1.1 t ha⁻\u0026sup1; in 2022 and 1.6 t ha⁻\u0026sup1; in 2023. In 2022, the application of biochar at rates of 2, 4, 6, and 8 t ha⁻\u0026sup1; led to yield increases of 63.6%, 100%, 136.4%, and 218.2%, respectively, compared to the control. In 2023, these application rates improved yields by 87.5%, 112.5%, 100%, and 106.3%, respectively, over the control. This demonstrates a strong correlation between increasing biochar application rates and grain yield, supporting findings from studies such as [24], which highlight biochar\u0026rsquo;s ability to enhance soil structure, nutrient retention, and moisture availability, ultimately leading to improved crop productivity.\u003c/p\u003e\n \u003cp\u003eGrain yields in 2023 were generally higher than those in 2022 across most treatments. This variability can be attributed to environmental factors such as rainfall distribution, temperature differences, and other climatic conditions that influence crop growth and the effectiveness of biochar. Research by [32] emphasizes the significance of climatic factors in determining the agronomic effectiveness of biochar. Notably, the consistency in yield at the highest application rate of 8 t ha⁻\u0026sup1; across both years suggests that this rate may mitigate the effects of environmental variability, providing stable benefits for maize production. These findings support previous research indicating that biochar application enhances soil fertility and productivity [33, 25]. However, the degree of improvement varies based on site-specific factors such as soil type, biochar characteristics, and crop management practices. While higher application rates resulted in the most substantial yield improvements, diminishing returns were observed beyond 8 t ha⁻\u0026sup1;, consistent with earlier studies [2].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec18\" class=\"Section3\"\u003e\n \u003ch2\u003e3.2.4. Hundred seed weight\u003c/h2\u003e\n \u003cp\u003eThe results indicate that the type of biochar significantly influenced the 100-seed weight in 2022, while no significant differences were observed in 2023 (Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). In 2022, rice husk and sawdust biochar outperformed groundnut husk biochar, suggesting that the type of biochar can enhance seed weight. This improvement is likely due to variations in nutrient composition and physical properties. Specifically, rice husk and sawdust biochars may offer better nutrient release, improved soil moisture retention, or enhanced conditions for root development [24]. These findings align with previous studies that suggest the nutrient-rich composition of certain biochars can support crop productivity by improving soil health and nutrient availability [33]. The positive impact of biochar application rate on 100-seed weight is illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e. In 2022, the highest 100-seed weight was recorded at a biochar application rate of 6 t ha⁻\u0026sup1;, which was statistically similar to the rates of 4 and 8 t ha⁻\u0026sup1;. In contrast, the control treatment consistently resulted in the lowest seed weights, highlighting the beneficial role of biochar amendments. In 2023, the maximum 100-seed weight was observed at the 8 t ha⁻\u0026sup1; application rate, followed closely by the 6 and 4 t ha⁻\u0026sup1; rates, which were statistically equivalent and significantly higher than the control. Furthermore, the 2 t ha⁻\u0026sup1; rate performed significantly better than the unamended control. These results are consistent with the findings of [29] and [13], who reported that biochar amendments improve seed development and yield quality. Biochar\u0026apos;s ability to enhance water retention, nutrient availability, and soil structure may explain these observed trends. Additionally, the slight variations between the years could be attributed to differences in environmental conditions, such as rainfall or temperature, which can influence crop responses to soil amendments [30].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e\n \u003ch2\u003e3.2.5. Harvest index\u003c/h2\u003e\n \u003cp\u003eThe harvest index, which indicates how efficiently a crop allocates biomass to grain, showed no significant differences across the various types of biochar in both study years (Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). This finding suggests that while biochar may enhance overall biomass production, the specific type of biochar does not significantly affect the proportion of biomass allocated to grains. These results align with previous studies indicating that biochar primarily influences general plant growth rather than directly altering the harvest index [34]. The impact of biochar application rates on the harvest index, illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e, revealed no significant differences during the first year. However, in the second year, biochar-treated plots showed a notable increase in the harvest index compared to the control. This trend supports evidence that the benefits of biochar application often become more pronounced over time as it integrates into the soil, improving critical properties such as nutrient retention, microbial activity, and water-holding capacity [35, 2]. The gradual improvement observed in this study may result from the slower nature of biochar\u0026apos;s effects. Biochar\u0026apos;s interaction with soil particles and organic matter enhances cation exchange capacity (CEC) and nutrient retention, processes that take time to stabilize and fully develop [33,36]. Specifically, the increase in the harvest index during the second year suggests that biochar\u0026apos;s cumulative effects significantly enhance grain yields relative to biomass production. These findings are consistent with [37], who noted that biochar\u0026apos;s impact on crop productivity tends to intensify in the growing seasons following its application. Biochar\u0026apos;s ability to enhance soil fertility by improving nutrient availability, soil structure, and water retention likely contributed to the observed increase in the harvest index [45]. Environmental factors, such as variations in rainfall and temperature, may also account for the differing impacts of biochar across years, as these conditions influence the rate at which biochar interacts with soil processes [50]. The benefits of biochar on crop yield may have been increased in the second year due to more favourable conditions for interactions between the biochar and the soil.\u003c/p\u003e\n \u003ctable border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 4\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eThe effect of biochar type on the cob weight, grain yield 100-seed weight, and harvest index of maize grown during the 2022 and 2023 cropping seasons.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eBiochar type\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eCob weight (t/ha)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eGrain yield (t/ha)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e100-seed weight (g)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eHarvest index (%)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003eCropping season\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRice husk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.7a\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.3a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.2a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e27.5a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.81a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.9a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGroundnut\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.2a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.9a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e27.1b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.0a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.84a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.9a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSaw dust\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.6a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.2a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.9a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e27.6a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.81a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.9a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLSD (5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.061\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"9\"\u003e\u003csup\u003e\u0026dagger;\u003c/sup\u003eValues with the same lowercase letters in a column in the year are not significantly different at p\u0026thinsp;\u0026lt;\u0026thinsp;.05.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003eTable \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e near here\u003c/p\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e near here\u003c/p\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e near here\u003c/p\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e near here\u003c/p\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e near here\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e\n \u003ch2\u003e3.3. Soil Chemical properties\u003c/h2\u003e\n \u003cdiv id=\"Sec21\" class=\"Section3\"\u003e\n \u003ch2\u003e3.3.1. Soil pH and organic matter\u003c/h2\u003e\n \u003cp\u003eThe influence of biochar on soil pH differed significantly between 2022 and 2023 (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). In 2022, there was no substantial variation in soil pH among the three types of biochar. However, in 2023, notable differences were observed. Both rice husk and groundnut husk biochar treatments produced similar pH values, which differed significantly from those recorded with sawdust biochar. The application rates of biochar had a pronounced effect on soil pH (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). The highest pH values consistently occurred at the 8 t ha⁻\u0026sup1; application rate. In 2022, nitrogen concentrations increased with biochar application rates of 2, 4, 6, and 8 t ha⁻\u0026sup1;, resulting in pH increases of 6.7%, 13.2%, 15.0%, and 17.6%, respectively, compared to the control. In 2023, the corresponding pH increases were even more pronounced, rising by 10.1%, 16.4%, 21.5%, and 26.0% over the control. These observed pH increases with biochar application agree with findings by [39] and [40], which indicated that the alkalinity of biochar often enhances soil pH. This enhancement is attributed to biochar\u0026apos;s ability to neutralize soil acidity and improve buffering capacity, especially in acidic soils. The higher pH levels observed in 2023 suggest cumulative effects, indicating that biochar can integrate with soil properties over time, leading to sustained improvements. Notably, the type of biochar did not significantly influence soil organic matter (SOM) in either year. This suggests that while biochar application typically increases SOM, the specific feedstock used to produce the biochar may not play a decisive role in short-term SOM enhancement. This finding is consistent with [29], who reported that biochar increases soil organic carbon (SOC), a major component of SOM, irrespective of feedstock type. The uniform effect of biochar across different types may be attributed to its inherent carbon content and its role in stabilizing existing organic matter in the soil. [34] pointed out that the long-term effects of biochar on SOM depend more on its stability in the soil than on the specific feedstock used. However, [45] suggested that variations in feedstock might produce distinct effects over extended periods or under different environmental conditions, particularly if the biochar contains varying nutrient levels.\u003c/p\u003e\n \u003cp\u003eThe rate of biochar application significantly impacted SOM levels, with the highest increases observed at the 8 t ha⁻\u0026sup1; application rate. In 2022, SOM increased by 89.6%, 188.0%, 234.4%, and 343.4% for application rates of 2, 4, 6, and 8 t ha⁻\u0026sup1;, respectively, compared to the control. A similar trend was observed in 2023, with SOM increasing by 93.4%, 206.6%, 284.6%, and 343.4% at the same application rates. These results underscore the effectiveness of higher biochar application rates in enhancing SOM levels. This aligns with the findings of [33], who noted that biochar enhances SOM by adding stable carbon and improving soil structure. Furthermore, [39] found that biochar\u0026rsquo;s impact on SOM could vary based on soil type, climate, and management practices\u0026mdash;factors that may overshadow the influence of biochar feedstock in short-term studies. The study demonstrates that biochar application improves soil pH and SOM, with these effects amplified at higher application rates. However, the type of biochar appears less critical in short-term enhancements. These findings reinforce the importance of biochar application rates as a determinant of its agronomic benefits and highlight its potential for improving soil health over time.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec22\" class=\"Section3\"\u003e\n \u003ch2\u003e3.3.2. N, P, and K\u003c/h2\u003e\n \u003cp\u003eThe type of biochar significantly influenced soil nitrogen (N) concentrations in both years of the study (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). In 2022, rice husk and groundnut husk biochar resulted in comparable nitrogen levels, both significantly higher than those observed with sawdust biochar. This trend persisted in 2023, with groundnut husk biochar consistently outperforming the others in enhancing nitrogen levels. The observed increase in soil N aligns with [29], who highlighted biochar\u0026apos;s role in improving nitrogen retention and availability due to its high surface area and cation exchange capacity (CEC). Nitrogen concentrations increased progressively with higher biochar application rates (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). For instance, in 2022, biochar application at 2, 4, 6, and 8 t ha⁻\u0026sup1; led to nitrogen increases of 70%, 140%, 190%, and 220%, respectively, over the control. In 2023, the corresponding increases were 30%, 55%, 70%, and 100%. These findings demonstrate biochar\u0026apos;s dose-dependent effect, corroborating [25], who reported that higher biochar rates improve nutrient availability by enhancing microbial activity and reducing nutrient losses. The cumulative nitrogen improvement over time can be attributed to biochar\u0026apos;s long-term stability and its gradual nutrient release [43]. Variability in nitrogen improvements between years might reflect climatic conditions or initial soil characteristics, as suggested by [37], who emphasized that biochar\u0026apos;s efficacy depends on environmental factors.\u003c/p\u003e\n \u003cp\u003eBiochar type significantly influenced soil phosphorus (P) levels during both years (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). In 2022, rice husk and groundnut husk biochar produced similar P levels, both higher than sawdust biochar. However, in 2023, groundnut husk biochar showed the highest P concentrations, while rice husk and sawdust biochar were statistically equivalent. These findings are consistent with [26], who noted that differences in biochar feedstock composition can influence nutrient release dynamics. Phosphorus levels increased markedly with higher biochar application rates (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). In 2022, biochar applied at 2, 4, 6, and 8 t ha⁻\u0026sup1; raised P levels by 23.8%, 37.9%, 42.5%, and 60.4%, respectively, compared to the control. In 2023, the increases were more pronounced at 44.7%, 53.8%, 59.3%, and 81.3%. The ability of biochar to enhance soil P can be attributed to its capacity for nutrient adsorption and gradual release, as reported by [45]. [46] also highlighted biochar\u0026rsquo;s potential to reduce nutrient leaching and improve plant-available P, particularly in nutrient-deficient soils.\u003c/p\u003e\n \u003cp\u003eSoil potassium (K) levels were significantly influenced by both biochar type and application rate across the study (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). In 2022, sawdust biochar recorded the highest soil K concentrations, while in 2023, rice husk and groundnut husk biochar showed comparable K levels, both higher than those obtained with sawdust biochar. These differences can be attributed to the mineral composition and nutrient release characteristics of the biochars, as noted by [41]. Potassium levels consistently increased with higher biochar application rates (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). In 2022, soil K rose by 161.5%, 253.8%, 307.7%, and 377.0% at 2, 4, 6, and 8 t ha⁻\u0026sup1;, respectively, over the control. In 2023, the corresponding increases were 100.0%, 181.3%, 253.8%, and 306.3%. These findings are consistent with [46], who emphasized biochar\u0026rsquo;s effectiveness in retaining and gradually releasing potassium, especially at higher application rates.\u003c/p\u003e\n \u003cp\u003eThe results demonstrate that biochar type and application rate significantly affect soil nutrient levels (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). Groundnut husk biochar exhibited superior performance in improving soil nitrogen and phosphorus levels, while sawdust biochar was more effective for potassium enhancement. Higher application rates consistently produced better results, emphasizing the importance of biochar dose in soil fertility management (Table \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). These findings underscore biochar\u0026rsquo;s potential as a sustainable soil amendment to enhance nutrient availability, especially in nutrient-deficient soils. Future research should investigate long-term effects and interactions with varying environmental conditions to optimize biochar use in agricultural systems.\u003c/p\u003e\n \u003ctable border=\"1\" class=\"fr-table-selection-hover\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 5\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eThe effect of biochar type and rate on the soil pH, Organic matter, N, P, and K after harvesting during the 2022 and 2023 cropping seasons\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"3\"\u003e\n \u003cp\u003eBiochar\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003epH (1:2.5 H\u003csub\u003e2\u003c/sub\u003eO)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eOM (%)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eN (%)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP (mg/kg)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eK (mg/kg)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003eYear\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2022\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2023\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eType (T)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRice husk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.61a\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.80a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.56a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.93a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.23a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.30a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.85a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e48.71b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.40b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.44a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGroundnut husk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.66a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.67a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.20a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.98a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.23a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.26b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e44.39a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e53.13a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.40b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.44a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSawdust\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.51a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.51b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.40a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.75a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.19b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.30a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.03b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e46.92b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.46a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.40b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLSD (5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRate (R)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.06d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.93e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.25e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.36e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.10e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.20d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e31.43d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.54c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.13e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.16e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.40c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.43d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.37d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.63d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.17d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.26c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.90c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e48.54b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.34d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.32d\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.73b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.74c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.60c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.17c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.24c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.31b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e43.27bc\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e51.59b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.46c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.45c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.82ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.99b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.18b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.23b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.29b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.31b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e44.78b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e53.44b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.53b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.55b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.95a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.21a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.54a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.03a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.32a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.34a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e50.42a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e60.82a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.62a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.65a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLSD (5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e(T x R)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.035\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"11\"\u003e\u003csup\u003e\u0026dagger;\u003c/sup\u003eValues with the same lowercase letters in a column in the year are not significantly different at p\u0026thinsp;\u0026lt;\u0026thinsp;.05. NS; Not significant.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003eTable \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e near here\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"4. Relationship between maize parameters and Soil chemical properties","content":"\u003cp\u003eThe correlation analysis highlights the positive impact of biochar application on maize yield and its association with soil chemical properties, providing valuable insights into biochar's role as a soil amendment (Tables\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e \u0026amp; \u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). The strong and positive correlations between yield parameters (such as plant height, cob weight, grain yield, and 100-seed weight) and soil properties (pH, organic matter, nitrogen, phosphorus, and potassium) emphasize the role of biochar in enhancing soil fertility and crop productivity. This agrees with findings from [46], who detailed biochar's potential to improve soil chemical properties by increasing nutrient availability, enhancing soil organic matter stability, and buffering soil pH. Nitrogen showed a consistent and significant correlation with maize yield, underscoring its essential role in crop productivity. The increase in soil nitrogen availability through biochar application is supported by [47], who observed that biochar enhances nitrogen retention by reducing leaching and increasing the soil's cation exchange capacity (CEC). This is particularly critical for tropical soils, where nutrient losses are high due to leaching and volatilization. The significant association between soil phosphorus and yield-related traits highlights biochar's role in nutrient cycling and microbial activity enhancement. Biochar contributes to phosphorus availability through sorption-desorption dynamics and interactions with soil microbes [6]. Furthermore, the positive relationship between organic matter and yield aligns with findings that biochar enhances soil structure, water retention, and microbial biomass, all of which contribute to better crop growth [48]. The lack of a significant relationship between the harvest index and soil properties, except for 100-seed weight, suggests that this trait may be influenced by factors beyond soil fertility, such as genotypic differences, climatic conditions, and crop management practices. [30] noted that the harvest index might not be as responsive to soil amendments as other yield parameters, emphasizing the need to consider additional physiological and environmental factors in its assessment.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCorrelation coefficient matrix for parameters during the 2022 season \u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"13\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePH\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSW\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCW\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eGY\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e100-SW\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eHI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003epH\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eOM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlant height\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStalk weight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.71***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCob number\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.68***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.87***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCob weight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.73***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.98***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.88***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrain yield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.71***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.000***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.87***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.98***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e100 seed weight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.52***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.66***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHarvest index\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.66***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.68***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.67***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.66***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.53***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOrganic matter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.73***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.83***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.82***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.83***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.83***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.71***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.66***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.85***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.84***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.85***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.85***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.64***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.69***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.85***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.60***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.69***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.70***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.69***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.58***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.65***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.72***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.68***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.80***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.88***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.79***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.80***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.72***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.68***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.88***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.83***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e0.589***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\u003cp\u003e( - ) not significant, ( * ) significant at p \u0026lt; 0.05, ( ** ) significant at p \u0026lt; 0.01, (***) significant at p \u0026lt; 0.001\u0026nbsp;\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCorrelation coefficient matrix for parameters during the 2023 Season\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"13\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePH\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSW\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCW\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eGY\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e100-SW\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eHI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003epH\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eOM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlant height\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStalk weight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.60***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCob number\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.45**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.60***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCob weight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.52***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.62***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.61***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrain yield\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.61***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.96***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.62***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.590***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e100-seed weight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.33*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.32*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHarvest index\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.53***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e-0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.60***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.40*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.51***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.62***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.72***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.54***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOrganic matter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.53***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.56***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.68***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.66***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.62***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.82***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.38*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.62***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.72***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.38*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.68***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.38*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.46**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.50***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.64***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.42**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.47**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.50***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.52***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.72***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.72***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.38*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.57***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.59***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.65***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.73***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.64***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.86***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.93***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.63***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e0.76***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"13\"\u003e( - ) not significant, ( * ) significant at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, ( ** ) significant at p\u0026thinsp;\u0026lt;\u0026thinsp;0.01, (***) significant at p\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e near here\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e near here\u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eThis study, titled \u003cem\u003eBiochar Types Effects on Soil Properties and Yield of Maize in Northern Region, Ghana\u003c/em\u003e demonstrates the potential of biochar as a sustainable soil amendment for improving soil fertility and maize yields in tropical agroecosystems. The findings underscore the importance of biochar type, application rate, and environmental conditions in determining its effectiveness. Groundnut husk biochar consistently exhibited superior performance in enhancing key soil nutrients such as nitrogen and phosphorus, while sawdust biochar excelled in improving potassium levels. This differentiation highlights the need for feedstock-specific recommendations to optimize biochar applications for nutrient-deficient soils. Higher biochar application rates (6\u0026ndash;8 t ha⁻\u0026sup1;) were shown to be optimal for improving critical yield parameters, including grain yield, 100-seed weight, and stalk weight, without diminishing returns. The study also highlights the role of biochar in sustaining long-term productivity by enhancing soil organic matter, pH, and nutrient retention, with the most significant improvements observed under the highest application rates. The strong positive correlations between soil fertility indicators and maize yield components reaffirm biochar's multifaceted benefits in promoting sustainable agricultural practices. This research is novel in integrating biochar\u0026rsquo;s specific feedstock effects, optimal application rates, and multi-year data to provide actionable insights for scaling its use in tropical agriculture. While the immediate effects on some yield parameters, like the harvest index, were modest, the cumulative benefits underline biochar's potential as a long-term investment in soil health and crop productivity. Future research should explore biochar's interactions with other soil amendments and its impacts under varying environmental conditions to refine its use across diverse agroecological systems. These insights serve as a foundation for leveraging biochar to address soil fertility challenges sustainably in Northern Ghana and beyond.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eThis work was conducted at the Savanna Agricultural Research Institute. We are thankful for the support of the management team. We also appreciate Mr. Alhassan Yamyolya Baako for monitoring and collecting data in the field.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors contributions:\u003c/strong\u003e All authors reviewed the manuscript Author contribution ALAA: conceptualization, investigation, data collection, methodology, data analysis, and full writeup. IAA, MMG, AH, MA and RA: Conceptualization, investigation, writing review, supervision, and editing. All authors read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of competing interest:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Publish Declaration:\u003c/strong\u003e Verbal informed consent was obtained from all participants after they were fully briefed on the study\u0026apos;s objectives, methodology, data collection procedures, and their rights, including the option to withdraw at any time without consequences. The corresponding author, affiliated with the CSIR-Savanna Agricultural Research Institute, is duly authorized to conduct the field experiments and data collection. All ethical guidelines established by the CSIR-Savanna Agricultural Research Institute for research, data collection, and analysis were strictly followed to ensure compliance with institutional and ethical standards.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate declaration:\u003c/strong\u003e not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Trial:\u003c/strong\u003e Not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e No available funding\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability:\u003c/strong\u003e The datasets generated during and/or analyzed during the current study are available within the paper.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLehmann, J. and Joseph, S. 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Routledge, London.https://doi.org/10.4324/9780203762264\u003c/li\u003e\n\u003cli\u003eWang, X., Liu, Q., \u0026amp; Lin, W. Feedstock-specific biochar for agricultural soil improvement: A meta-analysis. \u003cem\u003eAgriculture, Ecosystems \u0026amp; Environment\u003c/em\u003e, 349, 108801(2023). \u003c/li\u003e\n\u003cli\u003eSohi, S. P., Krull, E., Lopez-Capel, E., \u0026amp; Bol, R. (2010). A review of biochar and its use and function in soil. \u003cem\u003eAdvances in Agronomy, 105\u003c/em\u003e, 47\u0026ndash;82. https://doi.org/10.1016/S0065-2113(10)05002-9\u003c/li\u003e\n\u003cli\u003eLiu, X., Zhang, A., Ji, C., Joseph, S., Bian, R., Li, L., ... \u0026amp; Pan, G. Biochar\u0026apos;s effect on crop productivity and the dependence on experimental conditions\u0026mdash;a meta-analysis of literature data. Plant and Soil, 395(1-2), 241-261(2016). doi:10.1007/s11104-015-2536-1\u003c/li\u003e\n\u003cli\u003eSteiner C., Imogen B.-H., Volker H., Kwame T., Foster A., Kofi A., \u0026amp; Abdul Halim A., Gordana K.-B., Bernd M., Andreas B. Participatory trials of on-farm biochar production and use in Tamale, Ghana. Agronomy for Sustainable Development 38: 12(2018). https://doi.org/10.1007/s13593-017-0486-y \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"discover-agriculture","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Discover Agriculture](https://www.springer.com/journal/44279)","snPcode":"44279","submissionUrl":"https://submission.nature.com/new-submission/44279/3","title":"Discover Agriculture","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6127479/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6127479/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSoil degradation and declining crop productivity are persistent challenges in global agriculture, particularly in sub-Saharan Africa. While biochar application has gained recognition as a sustainable soil amendment, this study systematically evaluates the effects of different biochar feedstocks and application rates on soil fertility and maize productivity in Ghana. Three agricultural waste materials (rice husk, groundnut husk and sawdust) produced as biochar were evaluated under 5 application rates for improved grain yield, yield components and soil characteristics during the 2022 and 2023 cropping seasons under field experimental conditions. The treatment consisted of 2 factors: three biochar and five levels of biochar application rates (0, 2, 4, 6, and 8 t ha-1). Soil chemical properties, including pH, organic matter, and nutrient availability, were analysed alongside maize yield parameters. The study demonstrates that groundnut husk biochar is the most effective at enhancing soil fertility and boosting maize yields, with the highest application rate (8 t ha⁻\u0026sup1;) leading to remarkable grain yield increases\u0026mdash;up to 218.2% in 2022 and 106.3% in 2023. Soil organic matter content increased significantly, ranging from 89.6\u0026ndash;343.4%, while nitrogen availability peaked at 220% in 2022 and 70% in 2023. Maize yield showed a strong positive correlation with soil fertility parameters, except for the harvest index. These findings provide critical insights into optimising biochar use for sustainable maize production in similar conditions worldwide, demonstrating its potential to enhance soil health and long-term agricultural productivity.\u003c/p\u003e","manuscriptTitle":"Biochar Effects on Soil Properties and Yield of Maize in Northern Region, Ghana","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-24 14:54:50","doi":"10.21203/rs.3.rs-6127479/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-04-23T07:28:48+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-15T06:31:44+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-14T19:37:55+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-11T16:49:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"181028470805453814546917682951662494537","date":"2025-04-11T05:27:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"127807105634684989066917818035827175557","date":"2025-04-10T09:47:54+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"338314834186802276293913209948125852087","date":"2025-04-05T13:39:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"283147726018715414936162431667013427828","date":"2025-04-05T12:41:54+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"224191548484978616240023543347398092328","date":"2025-04-03T15:46:24+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-03T12:29:23+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-03-28T06:14:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-03-27T11:14:16+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-03-27T11:10:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Agriculture","date":"2025-02-28T09:53:51+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"discover-agriculture","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Discover Agriculture](https://www.springer.com/journal/44279)","snPcode":"44279","submissionUrl":"https://submission.nature.com/new-submission/44279/3","title":"Discover Agriculture","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5d142d02-aeeb-4887-9e01-aa20a958f249","owner":[],"postedDate":"April 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-06-23T05:23:09+00:00","versionOfRecord":[],"versionCreatedAt":"2025-04-24 14:54:50","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6127479","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6127479","identity":"rs-6127479","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}