Enhancing Maize Production in Mali: The Role of Fertilizer Microdosing and Mechanization in Improving Yield, Economic Returns, and Reducing Labor Use

Enhancing Maize Production in Mali: The Role of Fertilizer Microdosing and Mechanization in Improving Yield, Economic Returns, and Reducing Labor Use | 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 Enhancing Maize Production in Mali: The Role of Fertilizer Microdosing and Mechanization in Improving Yield, Economic Returns, and Reducing Labor Use Kamkam Woumou, Adama Coulibaly, Jens B. Aune This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5331059/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract The objectives of this study were to determine the optimal maize NPK microdosing rate in Mali and compare labor requirements for mechanized versus manual sowing and fertilization across three locations with varying rainfall. The treatments included five microdosing rates, ranging from zero to 93 kg NPK/ha (3 g NPK/hill), and the recommended rate of 100 kg NPK/ha applied by row application. All treatments also received an additional 150 kg urea/ha. Grain yield increased with application rates up to 93 kg/ha, resulting in a 1029 kg/ha (61.3%) increase compared to the control. The 63 kg NPK/ha microdosing rate resulted in a yield and economic return comparable to the application of 100 kg NPK/ha using row placement. The profitability of fertilizer use was evaluated by analyzing scenarios with both unfavorable and favorable ratios between fertilizer costs and grain prices. The 78.1 kg NPK/ha microdosing rate gave the highest average gross margin and VCR across the two price scenarios. The value-cost ratio was above the critical threshold of two in all fertilizer treatments, even under an unfavorable fertilizer-to-grain price ratio. Therefore, the risk associated with fertilizer use in maize is low, even if only non-subsidized fertilizer is available. The labour study showed that the manual application of seeds and microdosing of fertilizer averaged 11.4 man-days/ha, compared to 1.0 man-days/ha for the corresponding mechanized operation. Farmers will, therefore, not be likely to practice microdosing unless the operation is mechanized. maize microdosing urea mechanized sowing economic assessment Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 1. Introduction There is an increased interest in maize production in the drylands of West Africa due to its high productivity, high fertilizer response, the release of extra-early varieties, and improved resistance to birds compared to other dryland cereal crops. Under typical farming conditions in West Africa, maize yields range from 1.5 to 2.5 tons per hectare, significantly outperforming traditional dryland crops like pearl millet and sorghum [ 1 ]. Maize was introduced to Mali during the French colonial era and was initially cultivated as a backyard crop on soils with good soil fertility [ 2 ]. Maize became popular as it could be harvested at a green stage before the ripening of other crops. There has been a significant increase in the area cultivated with maize in Mali over the past decades. In 1961, maize was cultivated on around 100,000 hectares, increasing to 1,500,000 hectares by 2022 [ 3 ]. Total maize production in the same period increased by about 40 times, and yield increased from 0.8 tons/ha to 2.6 tons/ha [ 3 ]. Maize production in Mali has surpassed that of pearl millet [ 4 ]. The rise in maize output is due to CMDT's (the Malian textile company) intensification efforts in the 1980s, promoting cotton-maize rotation in Southern Mali and providing access to fertilizers, improved seeds, and pesticides. The recommended fertilizer application rate is 100 kg NPK/ha as a basal dressing and 150 kg/ha of urea as a top dressing. However, due to limited access to fertilizers and financial constraints, many farmers have been unable to apply the recommended rate. Research conducted in other parts of Africa has found that microdosing, which involves applying small fertilizer quantities adjacent to the plant hill, is an efficient method for fertilizer application [ 5 ]. In Benin, the application of 23.8 kg N/ha and 4.1 kg P/ha (2 g NPK per hill) as microdosing increased maize yield by 64%, while the recommended rate of 76 kg N/ha and 13.1 kg P/ha increased yield by 93% [ 6 ]. The development of heat and drought-resistant, extra-early maize varieties that mature in just 80 to 90 days and require only 500 mm of rainfall has significantly increased maize production in the drylands [ 7 , 8 ]. Capitalizing on this progress, an IITA project on Climate Smart Agriculture has been actively promoting maize cultivation since 2018 in the drier regions north of Mali's cotton belt, where these varieties are particularly well-suited to thrive. Expanding maize to the north will mean that it will replace sorghum and, to some extent, millet. However, maize is more labor-demanding to grow than the other dryland cereals because it is planted at a higher plant density (31,250 hills/ha) than sorghum (25,000 hills/ha). Therefore, promoting mechanized sowing, fertilizer application, and weeding is advantageous to ensure that seeds and fertilizers are placed at optimal density, depth, and rates. Experience from millet production in Mali shows that 14% higher yields can be expected when farmers practice mechanized sowing compared to manual sowing [ 9 ]. The objectives of this study were to identify optimal agronomic and economic microdosing rates in maize across a rainfall gradient and to assess the effects of mechanized sowing and fertilizer application on labor use in maize production. 2. Materials and methods The study included two field trials: one to identify the response curve to increasing microdosing rates and another to assess the time use of mechanized seed and fertilizer application compared to manual operations. 2.1 Microdosing rates experiment The field trials on increasing microdosing rates were established along a rainfall gradient. The field trials were conducted in the villages Kaboïla in the Sikasso region, Sotuba (Regional Research Station) in Bamako, and Maféya in the Koulikoro region. The sites can be characterized as follows: Kaboïla, Guinean zone, average rainfall 1000 mm Sotuba, Sudanian zone, average rainfall 800–900 mm Maféya, border areas between Sudanian zone and Sudano-Sahelian zone, average rainfall 600–700 mm The microdosing experiment was a randomized block trial with five replications at each site. Maize was sown at a row distance of 80 cm and an interrow spacing between hills of 40 cm, giving a planting density of 31,250 planting hills/ha. There were about two plants per hill. The maize variety used was Sotubaka, with a growth cycle of 120 days from sowing to maturity. The experimental plot size was 4.8 x 4.8 meters. Each plot had six rows, and the two central rows were harvested. The fertilizer treatments were as follows: No fertilizer 0.5 g fertilizer per hill, corresponding to 15.6 kg NPK/ha 1 g fertilizer per hill, corresponding to 31.2 kg NPK/ha 1.5 g fertilizer per hill, corresponding to 46.8 kg NPK/ha 2 g fertilizer per hill, corresponding to 62.5 kg NPK/ha 2.5 g fertilizer per hill, corresponding to 78.1 kg NPK/ha 3 g fertilizer per hill, corresponding to 93,7 kg NPK/ha 100 kg NPK/ha applied as row application All treatments received 50 kg urea/ha broadcasted at germination, followed by 100 kg urea/ha row applied at maize knee height. In the years 2022 and 2023, two urea treatments were introduced. In one treatment, the application of 75kg/ha urea was split in two: 25 kg urea/ha applied at sowing and 50 kg/ha at knee height, while in the second treatment, 150 kg urea /ha was used as in the first two years of the experiment. To evaluate the economic return of fertilizer application, we collected price data on grain, stover, and mineral fertilizer. According to FAOstat [ 3 ], maize farm gate prices ranged from 110 to 200 FCFA from 2020–2023, with farmers reporting similar prices at maturity. An average price of 160 FCFA was used for this period, and 110 FCFA as the minimum price. Fertilizer (NPK 16-16-16) is priced at 500 FCFA/kg without a subsidy, but farmers typically access it at 250 FCFA/kg due to a 50% subsidy provided through CMDT. Straw was sold at an average of 40 FCFA/kg. For profitability analysis based on gross margin and Value-Cost Ratio (VCR), two scenarios were considered: 1. Regular scenario: grain at 160 FCFA/kg, fertilizer at 250 FCFA/kg, and stover at 40 FCFA/kg. 2. Worst-case scenario: grain at 110 FCFA/kg, fertilizer at 500 FCFA/kg, and stover at 40 FCFA/kg. 2.2 Effect of mechanization on time-use A trial was conducted to assess the effect of mechanization on time use and compare the yield of manually applied recommended fertilizer rates with reduced rates applied using planters (Fig. 1 ). One of the planters tested was a modified version of the Super-ECO planter to which a fertilizer distribution unit was added. This allowed the simultaneous application of seeds and mineral fertilizer. The trial also included the Gangaria planter, a planter newly developed in Niger, that simultaneously applies seeds and organic fertilizer/compost in one operation [ 10 ]. The treatments were as follows: Manual sowing and manual application of 3.2 g NPK per planting hill (100 kg /ha) Use of the double hopper Super-ECO planter to apply seeds and 1.5 g NPK per planting hill (46.8 kg/ha) Use of the Gangaria planter for sowing and application of 50 g compost per hill (1.56 t /ha) In addition to the fertilizer applied in these treatments, each treatment also received 100 kg urea/ha row applied in two splits: 50 kg/ha 15 days after sowing and 50 kg/ha at knee height. Each plot measured 900 m², and yield was measured by harvesting ten randomly distributed one-square-meter quadrats in each plot. The test was conducted over four years, from 2020 to 2023. Labor use was assessed by measuring the time required to complete the operation in each plot. The time-use in the manual treatment (treatment 1) included the work of three persons: one person opened a small planting pit, a second person placed the seed in the planting pit, and a third person added 3.2 g of fertilizer per planting pit. Two persons were used in mechanized sowing: one person steered the planter while the second person controlled the direction of the donkey. Labor use was converted into man-hours/ha. 2.3 Statistical analyses "The data were analyzed using analysis of variance (ANOVA), and means were separated using standard deviation and the Tukey test." JMP (version 17.2) was the statistical software used to analyze the data. 3. Results Results are presented on site conditions, the effect of increased microdosing rates on yield components, grain and stover yield, gross margin, value-cost ratio, and the impact of mechanization on time-saving and the yield effect of mechanized application combined with lower fertilizer rates. 3.1 Rainfall and soil properties at the experimental sites Even though the three sites were in different climatic zones, there were no major differences between them regarding average rainfall from 2020 to 2023 (Fig. 2). The average rainfall for the period at the sites Kaboïla, Sotuba, and Maféya was 824, 911, and 877 mm, respectively. The figure shows that rainfall was evenly distributed throughout the growing seasons at Sotuba and Maféya. In contrast, Kaboïla experienced greater variability between seasons and more frequent dry spells within the growing seasons. The soils at all three experimental sites were classified as loamy sand, and the soil properties did not differ significantly between the sites (Table 1 ). The soils were sampled at the start of the experiment and at the end four years later, but no major changes in soil properties were observed. The soil fertility of these sites can be considered low, particularly due to the low levels of nitrogen, phosphorous, and potassium. Table 1 Soil chemical- and physical properties at Kaboïla, Maféya, and Sotuba sites. Kaboïla Maféya Sotuba Rating* pH (water) 5.12 5.12 5.28 Low SOC% 0.62 0.26 0.56 Very low N % 0.04 0.02 0.04 very low P-Bray 13.5 13.4 13.3 Low CEC meq/100g 4.50 4.44 4.41 Very low Ca meq/100g 2.44 2.34 2.36 High Mg meq/100g 1.25 1.26 1.19 High K meq/100g 0.16 0.15 0.11 Low-medium Na meq/100g 0.07 0.07 0.05 Low Sand % 65 66 68 Silt % 26 27 26 Clay % 9 8 7 *Rating of soils based on Landon 1984. 3.2 Agronomic effects of microdosing in maize The agronomic effects of fertilizer were assessed based on the number of hills harvested per hectare and the number of cobs per hectare. There was no statistically significant effect of fertilizer rate on either of these variables. The average plant stand at harvest across the years and sites was approximately 28,948 hills per hectare, representing a plant stand of 92.6%. On average, there were about 44,000 cobs per hectare across the years and sites. The grain yield differed significantly among the three sites, with average grain yields of 2657 kg/ha for Kaboïla, 2878 kg/ha for Sotuba, and 1303 kg/ha for Mafeya (Fig. 3 ). No interaction was observed between sites and fertilizer rates, or years and fertilizer rates. The grain yield increased with increasing microdosing rates up to 93.7 kg NPK/ha, but there were only minor differences among the three highest microdosing rates and the differences were not statistically different. The good response to fertilizer in these trails was expected since nitrogen, phosphorous, and potassium levels were low in the soils. Yield increased from the control to the highest microdosing rate (93.7 kg/ha) by 1253 kg/ha in Kaboïla, 936 kg/ha in Maféya, and 897 kg/ha in Sotuba. The treatment of 100 kg NPK/ha, applied by row application, resulted in a lower yield than the highest microdosing rate, but this difference was not significant at any of the sites. Increasing microdosing rates significantly increased maize grain yield when summarized across four years and three sites (Fig. 4 ). The five highest fertilizer rates produced a significantly higher yield than the control. The 93.7 kg NPK/ha rate also gave a significantly higher yield than 46.9 kg/ha and below. Applying 93.1 kg NPK/ha as microdosing increased yield by 1029 kg/ha compared to the control, representing a 61.3% increase in yield. This corresponds to a fertilizer use efficiency (FUE) of 11.4 kg per kg NPK. Application of the recommended dose of 100 kg NPK/ha gave a FUE of 7.88. The 62.5 kg NPK/ha microdosing rate produced a yield comparable to that achieved with a row application of 100 kg NPK/ha. 3.3 Straw yield and harvest index As for grain yield, the straw yield increased significantly with increasing fertilizer rates (Fig. 5 ). No interactions were found between site and fertilizer rates or between the years and the fertilizer rates. The 62.5 kg/ha fertilizer rate and above produced a significantly higher yield than the control. The highest yield was obtained with a microdosing rate of 78.1 kg NPK/ha, which increased straw yield by 1216 kg/ha compared to the control (45.3% increase ). The application of 62.5 kg NPK/ha as microdosing resulted in a yield similar to that of 100 kg NPK/ha applied by broadcasting. The fertilizer treatments did not significantly affect the harvest index. However, the harvest indexes in Maféya, Kaboïla, and Sotuba were 27.0, 53.7, and 40.4, respectively. 3.4 Gross margin and Value-Cost-Ratio The economic assessment was based on the gross margin and the value-cost ratio (VCR). The gross margin only included the costs that differed between the treatments, making it a partial gross margin analysis. Two scenarios were considered: one with regular grain prices and 50% subsidized fertilizer and a worst-case scenario with low grain prices and unsubsidized fertilizer. There was no interaction between location and fertilizer or year and fertilizer. Therefore, only the average results across sites and years are presented. There was a significant difference in gross margin between the treatments in both price scenarios (Fig. 6 ). The Tukey separation test showed that the 62.5, 78.1, 93.7, and 100 kg NPK/ha treatments had significantly higher gross margins than the control in both price scenarios. The treatment 78.1 had a gross margin that was only marginally lower than the 93.1 kg NPK treatment in the regular price scenario and produced the highest gross margin in the worst-case price scenario. The treatment 78.1 increased the gross margin compared to the control by 47.0% in the regular price scenario and 38.1% in the worst-case scenario. The application of 15.6 kg NPK/ha increased the gross margin by 19.8% compared to the control in the regular price scenario, but this increase was not significant. Row application of 100 kg NPK/ha resulted in a lower gross margin than the microdosing rates of 62.5 kg/ha in both price scenarios, but this difference was not significant. For the value-cost ratio (VCR), there were significant differences between the treatments in both scenarios, with the VCR exceeding the critical value of 2 in all scenarios and treatments (Fig. 7 ). The VCR was about 62% lower in the worst-case scenario than the regular price scenario. The highest VCR was obtained with the microdosing treatment of 15.6 kg NPK/ha, with a VCR of 20.1 in the regular price scenario and 7.5 in the worst-case scenario. The lowest VCR in both scenarios was obtained with the broadcasting treatment of 100 kg NPK/ha, yielding a VCR of 2.5 in the worst-case scenario. 3.5 Effect of urea top-dressing The urea application rates of 75 and 150 kg/ha were tested at all sites in 2022 and 2023. The urea application rates did not significantly affect the number of hills harvested per hectare, cobs harvested per hectare, or grain yield across the three sites and two years. Nor was there any significant interaction between these microdosing and urea rates on these variables. Time-use and yield effect of mechanized application of seeds and fertilizer compared to manual operations A three-year experiment was conducted at the Sotuba and Maféya sites to evaluate the time efficiency and yield impact of three different methods: (1) manual sowing and manual application of 3.2 g NPK/hill corresponding to 100 kg NPK/ha (recommended rate), (2) using the donkey-drawn modified Super ECO planter to sow and apply about half the recommended fertilizer rate, and (3) using the donkey-drawn Gangaria planter to sow and apply 1.5 tons of compost per hectare. A significant difference in time-use was observed between manual sowing and the two mechanized sowing methods (Fig. 8 ). The average time-use for the manual operations was 11.3 man-days per hectare, compared to 0.95 man-days per hectare for the two mechanized operations. Mechanized sowing is, therefore, about 12 times faster than manual sowing. There was no significant difference in time-use between the two mechanized operations. The yield levels in the time-use experiments corresponded with the results from the microdosing experiment, and the yield levels at the two sites were equal. The yield components, specifically the number of hills harvested per hectare and cobs harvested per hectare, differed significantly between the treatments (Table 2 ). The treatment with manual application of the recommended fertilizer rate performed better than the two mechanized treatments, particularly compared to the Gangaria planter with compost. The grain yield with the recommended fertilizer treatment was 29.3% higher than with the Gangaria planter and organic fertilizer, and 18.6% higher than with the Super-Eco planter and half the recommended application rate (Table 2 ). Stover yield in the treatment using the recommended fertilizer rate was 35.0% higher than in the treatment with the use of the Gangaria planter and application of 1.5 tons of compost per hectare and 9.7% higher than in the treatment with the Super-Eco planter and a reduced fertilizer rate. Table 2 Effect of mechanization and fertilizer application rate on no. harvested hills(ha, no. harvested cobs/ha, stover yield, and grain yield (different letters mean statistical differences based on the Tuckey test). Treatment No. hills harvested/ha No. cobs harvested/ha Stover yield kg/ha Grain yield kg/ha Manuel sowing + 100 kg NPK/ha 24933 a 42952 a 2776 a 1768 a Super eco planter + 46.8 kg NPK/ha 22787 a 34793 b 2530 b 1490 b Gangaria planter + 1.56 ton manure/ha 20836 b 31165 c 2065 b 1367 c Average 22852 36303 2457 1542 Significance P < 0.0001 P < 0.0001 P < 0.0005 P < 0.0001 4. Discussion The discussion will focus on explaining maize's agronomic and economic performance at the three experimental sites. Additionally, we will explore how planters can reduce labour use. 4.1 Effect on yield The microdosing treatment with 93.7 kg NPK/ha performed the best at all sites, resulting in yield increases compared to the control at Kaboïla, Sotuba, and Maféya by 1252, 936, and 897 kg/ha, respectively. The response to microdosing was also good in Maféya, despite its location north of the cotton belt. However, the harvest index in Maféya was only 27.0%, compared to an average of 47.1% at Kaboïla and Sotuba. The lower harvest index in Maféya is hard to explain, as rainfall data shows no end-of-season drought in any of the years. When the results were summarized across the years and sites, the grain yield increased with increasing microdosing rates up to 93.1 kg/ha (3 g NPK per planting hill). The four highest fertilizer rates resulted in significantly higher yields than the control. The fertilizer rate did not significantly influence the yield components, such as the number of harvested hills/ha and the number of cobs/ha. Therefore, the increase in grain yield with increasing fertilizer rate is likely due to more grains per cob and/or a higher kernel weight. The good response to fertilizer in these trails was expected since nitrogen, phosphorous, and potassium levels were low in the soil. The treatment of 93.1 kg NPK/ha increased grain yield compared to the control across the three sites on average by 1029 kg/ha (61.3% increase). The fertilizer use efficiency was 11.4 kg of grain per kg of fertilizer applied, representing a good response to fertilizer. The yield with 62.6 kg fertilizer/ha applied as microdosing matched that of 100 kg NPK/ha applied by row application, suggesting more efficient fertilizer use in microdosing. The highest stover yield was achieved when applying 78.1 kg NPK/ha as microdosing. This treatment increased stover yield by 1216 kg/ha (45.2%) compared to the control. The 93.7 kg NPK/ha rate increased maize grain yield by 61.3%, showing that fertilizer has a relatively better effect on grain yield than stover yield. The highest microdosing rate increased yield compared to the control by 1029 kg/ha, a fertilizer response beyond what has been observed in pearl millet and sorghum production in central and southern Mali [ 11 ]. This suggests that if farmers cannot afford fertilizer for all their cereal crops, it is advisable to prioritize its use on maize. 4.2 Economic assessment The gross margin and VCR analyses indicated that all the fertilizer rates tested are profitable. The 78.1 kg NPK/ha rate produced a gross marginally lower than 93.5 kg NPK/ha in the regular scenario, while it gave the highest gross margin in the worst-case scenario. The increase in gross margin between the control and the treatment 78.1kg NPK/ha in the regular price scenario was 176,789 FCFA (47.0% increase), while the corresponding increase in the worst-case scenario was 111,118 FCFA (38.1% increase). The difference in gross margin is moderate between the two scenarios, even though the ratio between fertilizer and grain was 4.5 in the worst-case scenario and 1.5 in the regular price scenario. Our study thus shows that fertilizer is profitable even under an unfavorable ratio between prices of fertilizer and grain. The VCR (value-cost ratio) in the treatment 78,1 was 8.7 in the regular price scenario, while this treatment produced a 3.9 in the worst-case scenario. Both values exceed the critical VCR threshold of two [ 12 ]. Despite the high gross margin, applying 100 kg NPK/ha by row application is risky, as shown by a VCR of 2.5 in the worst-case scenario. For resource-constrained farmers who can only purchase fertilizer in small quantities, applying 15.6 kg NPK/ha using microdosing can be an interesting alternative, as this rate gave a VCR of 20.1 in the regular scenario and increased the gross margin compared to the control by 74,545 FCFA/ha (20% increase). 4.3 Mechanization of sowing and fertilizer application Planting time is hectic for the farmers in central and southern Mali. To address this problem, the project developed a planter that can simultaneously apply seeds and mineral fertilizer. Mechanized sowing and microdosing, compared to manual application of seeds and manual microdosing, were found to save about 10 man-days/ha. The area under maize in the cotton belt is about 2.6 ha [ 13 ], implying that it would take about 26 additional days to do the work manually compared to using mechanization. Planters are, therefore, essential to ensure timely sowing and microdosing application. Yield was lower in the two treatments with mechanization compared to the recommended rates. This is likely due to the lower fertilizer rates used in these treatments. In the treatment with the Super-eco planter, 46 kg NPK/ha was used, resulting in an 18.6% lower yield than the recommended rate. This yield reduction in this treatment is equal to the yield reduction in the treatment with 46.8 kg NPK/ha in the microdosing study. Mechanized sowing and fertilizer application in maize is becoming increasingly important in Mali and other West African countries as the area under maize is rapidly expanding [14]. A previous study on mechanization in Mali [ 9 ] found that using a motorized planter is economically viable when the cereal cultivation area exceeds five hectares—a condition met by many farmers in southern Mali. The current practice for maize sowing involves opening a small pit, placing the seeds in it, and then broadcasting fertilizer by hand. Farmers will not likely change from broadcasting/row application of fertilizer to manual microdosing because of the labor use associated with this method. Microdosing will become interesting if a planter is used to apply seeds and fertilizer simultaneously. Furthermore, utilizing planters will ensure that seeds and fertilizer are placed at an optimal depth, rate, and spacing. 5. Conclusion The economic analysis showed that the microdosing rate of 78.1kg NPK/ha is the best choice, as it gave a gross margin comparable to the 93.1 kg NPK/ha rate when using subsidized fertilizer and a better gross margin with unsubsidized fertilizer. However, the use of fertilizer, whether through microdosing or row application, is recommended, as the Value Cost Ratio (VCR) exceeded the critical threshold of 2 across all treatments. This holds true even in scenarios where only unsubsidized fertilizer is available and grain prices are low. The study also revealed that using a planter to apply seeds and fertilizer as microdosing saved ten days per hectare compared to the manual sowing and microdosing application. Farmers are not likely to change from fertilizer broadcasting/row application to mechanized application unless they get access to planters. In conclusion, the study demonstrated that using mineral fertilizer in maize cultivation remains viable even without subsidies. Mechanized fertilizer application is recommended to ensure timely operations and enhance fertilizer use efficiency. Declarations This research was funded by the Norwegian Ministry of Foreign Affairs through the IITA project “Climate Smart Agricultural Technologies (CSAT). The authors have no relevant financial or non-financial interests to disclose. The data are publicly available. Ethical statement The species used in this experiment was maize (Zea mays (L.)) and is available in the herbarium of Royal Botanic Gardens, Kew, UK. The herbarium barcode number is K000632872. The maize variety used was the Sotubaka, developed by the Maize Program of Institute d’Economie Rurale (IER) in Mali. The variety is listed in IER catalogue of recommended varieties and is widely used by the farmers in Mali. The research was undertaken in collaboration with the Maize Program of IER. The use of this variety complies with national guidelines with no need for further affirmation. The research protocol of this study was approved by the Research Committee of IER, the Scientific Commission of Centre National de Research Agricole (CNRA) and by the director of the Climate Smart Agricultural Technologies (CSAT) program of International Institute of Tropical Agriculture (IITA). Authorship contribution: Conceptualization and methodology: [A. Coulibaly, K. Woumou, J.B. Aune], Conducting field trials [A. Couliblay, K.Woumou], Statistical analysis [A. Couliblay, K.Woumou, J.B. Aune], Graphics [J.B. Aune], Writing [A. Coulibaly, K. Woumou and J.B. Aune] References Fusillier JL (1994) Western Africa: maize or sorghum. Agriculture and Development-special issue. https://agritrop.cirad.fr/387424/1/document_387424.pdf Laris P, Foltz JD (2014) Cotton as Catalyst? The Role of Shifting Fertilizer in Mali’s Silent Maize Revolution. Hum Ecol 42, 857–872. https://doi.org/10.1007/s10745-014-9694-0 FAOstat 2024. https://www.fao.org/statistics/en Wiggins S, Allen M, Barry B, Mami E, Patel N, Sulieman H (2023) Food prices in Mali and Sudan: changes, causes, consequences and responses. London: SPARC. https://www.sparc-knowledge.org/sites/default/files/documents/resources/report-food-prices-in-mali-and-sudan.pdf Coulibaly A, Woumou K, Aune JB (2019) Sustainable intensification of sorghum and pearl millet production by seed priming, seed treatment and fertilizer microdosing under different rainfall regimes in Mali. Agronomy 9:664. https://doi.org/10.3390/agronomy9100664 . Tovihoudji PG, Irenikatché Akponikpè PB, Agbossou EK, Bertin P, Bielders CL (2017) Fertilizer microdosing enhances maize yields but may exacerbate nutrient mining in maize cropping systems in northern Benin. Field Crops Res 213, 130–142. https://doi.org/10.1016/j.fcr.2017.08.003 . Konate L, Badu-Apraku B, Coulibaly M, Menkir A, Laouali MN, Meseka S, Mengesha W (2023) Agronomic performance and yield stability of extra-early maturing maize hybrids in multiple environments in the Sahel. Heliyon 9, e21659, https://doi.org/10.1016/j.heliyon.2023.e21659 . Wossen T, Menkir A, Alene A, Abdoulaye T, Ajala S, Badu-Apraku B, Gedil M, Mengesha W, Meseka 8 (2023) Drivers of transformation of the maize sector in Nigeria. Global Food Secur 38:100713. https://doi.org/10.1016/j.gfs.2023.100713 . Aune JB, Coulibaly A, Woumou K (2019) Intensification of dryland farming in Mali through mechanisation of sowing, fertiliser application and weeding. Arch Agron Soil Sci 65:400–410. https://doi.org/10.1080/03650340.2018.1505042 . Nourou AIM, Saidou AK, Aune JB (2020) Development and use of a planter for simultaneous application of seed, fertilizer and compost in pearl millet production in Niger—effects on labor use, yield and economic return. Agronomy 10:1886. https://doi.org/10.3390/agronomy10121886 . Landon J (1984) Booker Tropical Soil Manual. Booker Agriculture Internation Limited, London, 450 p. Morris M, Kelly VA, Kopicki RJ, Byerlee D (2007) Fertilizer use in African agriculture: lessons learned and good practice guidelines. World Bank; Direction in Development-Agriculture and Rural Development, No. 39037. https://documents1.worldbank.org/curated/en/498591468204546593/pdf/390370AFR 0Fert101OFFICIAL0USE0ONLY1.pdf Westerberg V, Diarra A, Diallo H, Diallo S, Kone B, Domergues M, Keita O, Doku A, Di Falco SD (2020) The economics of cotton production in Mali and the challenges of land degradation. Case study in Koutiala and Bougouni. https://www.eld-initiative.org/fileadmin/Regreening_Africa_publications/ELD-Mali-Report-web-EN.pdf . Additional Declarations No competing interests reported. Supplementary Files Ureatest20222023.xlsx agronecondata.xlsx labouruse.xlsx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 28 Nov, 2024 Reviews received at journal 27 Nov, 2024 Reviews received at journal 20 Nov, 2024 Reviewers agreed at journal 17 Nov, 2024 Reviewers agreed at journal 14 Nov, 2024 Reviewers invited by journal 14 Nov, 2024 Editor assigned by journal 11 Nov, 2024 Submission checks completed at journal 09 Nov, 2024 First submitted to journal 25 Oct, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5331059","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":380526729,"identity":"c7693546-bb46-42be-82c4-1e52a505597f","order_by":0,"name":"Kamkam Woumou","email":"","orcid":"","institution":"Insitute D’Economie Rurale (IER)","correspondingAuthor":false,"prefix":"","firstName":"Kamkam","middleName":"","lastName":"Woumou","suffix":""},{"id":380526730,"identity":"770e4fa7-169e-4179-807a-7a1f111850cf","order_by":1,"name":"Adama Coulibaly","email":"","orcid":"","institution":"Insitute D’Economie Rurale (IER)","correspondingAuthor":false,"prefix":"","firstName":"Adama","middleName":"","lastName":"Coulibaly","suffix":""},{"id":380526731,"identity":"d0fdb5ce-58a4-45cb-b001-65d543451875","order_by":2,"name":"Jens B. Aune","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYBACxgYYi72BgZlELTwHiNSCABIJRGphbu89/IGh5nAev+Tbo5sL2xjy+Ak6rOdcmgTDscPFkrPz0m7PbGMolmwgpGVGjhkDA9vhxA23c8xu87YxJG44QEjL/DfGHxj+HU7cf/MMsVpm8BhIMLYBbZHgIVZLT46ZRGJfeuKMM0CHzTgnkTiTkF8M288Yf/jwzTqxvx3osIIym8R+AjoYDEFmJiD4EoQ0MDDIE1YyCkbBKBgFIx4AAKwyQVsrzPIuAAAAAElFTkSuQmCC","orcid":"","institution":"Norwegian University of Life Sciences (NMBU)","correspondingAuthor":true,"prefix":"","firstName":"Jens","middleName":"B.","lastName":"Aune","suffix":""}],"badges":[],"createdAt":"2024-10-25 09:08:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5331059/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5331059/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":70019381,"identity":"46156565-8fbf-496f-aeb5-5041584f54cb","added_by":"auto","created_at":"2024-11-27 14:31:16","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1380080,"visible":true,"origin":"","legend":"\u003cp\u003eSowing using the Super-eco planter with two hoppers (left) and Gangaria planter with \u0026nbsp;two hoppers (right)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/4f5c030a263f17c34991d827.png"},{"id":70018504,"identity":"66ee95e6-1ed8-4de1-88d8-ff5ec913e83b","added_by":"auto","created_at":"2024-11-27 14:23:16","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":183200,"visible":true,"origin":"","legend":"\u003cp\u003eCumulative rainfall from 2020 to 2023 for Kaboïla, Sotuba, and Mafeya sites.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/4538d64032ef7d5e5760b062.png"},{"id":70017681,"identity":"81d6e4bd-aba5-422c-992d-8a5c65b0181e","added_by":"auto","created_at":"2024-11-27 14:15:16","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":80603,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of increasing microdosing rate on the maize grain yield for three sites across four seasons. The treatment of 100 kg NPK/ha was applied by row application. The error bars represent standard deviation and columns with different letters are significantly different according to the Tukey test.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/afed87ac6c8f1445b66eb1f9.png"},{"id":70017683,"identity":"66ac437f-aee9-42a5-ac8d-30524df0e09e","added_by":"auto","created_at":"2024-11-27 14:15:16","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":16029,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of increasing microdosing rates on grain yield summarized across three sites and four years. The treatment of 100 kg NPK/ha was applied by broadcasting. Non-overlapping letters correspond to significant differences according to the Tukey test.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/0c42e148a96e9c596e474439.png"},{"id":70018507,"identity":"1ec9177a-74cd-4332-a415-14dbc78fa1db","added_by":"auto","created_at":"2024-11-27 14:23:16","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":16272,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of increasing microdosing rates on stover yield summarized across three sites and four years. The treatment of 100 kg NPK/ha was applied by row application. \u0026nbsp;Columns with different letters are significantly different according to the Tukey test.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/b0dadc0905df2db3287bf3e6.png"},{"id":70017691,"identity":"b51bff60-a385-4571-a2f9-d7461e8a4e10","added_by":"auto","created_at":"2024-11-27 14:15:16","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":48490,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of increasing microdosing rate in a regular price scenario and in a worst-case scenario on gross margin. Columns with different letters are significantly different according to the Tukey test.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/0e39ee92c4139be4a2121d4f.png"},{"id":70019382,"identity":"480013a7-5504-4453-bf09-dbf5bf993884","added_by":"auto","created_at":"2024-11-27 14:31:16","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":38617,"visible":true,"origin":"","legend":"\u003cp\u003eRelation between fertilizer rate and value-cost-ratio (VCR). \u0026nbsp;The threshold value of 2 is indicated. Columns with different letters are significantly different according to the Tukey test.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/be60542aa1ba625e7ea840e8.png"},{"id":70017688,"identity":"66f57c02-1537-42bc-8583-8412c554406e","added_by":"auto","created_at":"2024-11-27 14:15:16","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":21750,"visible":true,"origin":"","legend":"\u003cp\u003eLabour use in man-days/ha in manual sowing compared to applying seed and fertilizer using the Super-eco planter and Gangaria planter at two sites.\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/015a3f7d38f71aca25800855.png"},{"id":70020590,"identity":"d6463e57-b020-4561-b572-4e7b84ac539e","added_by":"auto","created_at":"2024-11-27 14:39:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2700818,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/de8fd8a1-d802-4ed9-8945-9379dbe0b032.pdf"},{"id":70018501,"identity":"f373ed66-e08c-4e05-bb6c-3adea84dfd91","added_by":"auto","created_at":"2024-11-27 14:23:16","extension":"xlsx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":41053,"visible":true,"origin":"","legend":"","description":"","filename":"Ureatest20222023.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/6f9ddf7f9a5734a0ac176bdb.xlsx"},{"id":70017689,"identity":"49a32f6e-0f69-440f-a9d3-be727b840e66","added_by":"auto","created_at":"2024-11-27 14:15:16","extension":"xlsx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":43192,"visible":true,"origin":"","legend":"","description":"","filename":"agronecondata.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/d8518cc111ae458f1d243fee.xlsx"},{"id":70019384,"identity":"833f974d-84c6-4d1a-9892-b0d85c980719","added_by":"auto","created_at":"2024-11-27 14:31:16","extension":"xlsx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":10138,"visible":true,"origin":"","legend":"","description":"","filename":"labouruse.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-5331059/v1/82c8000632fadd91dd41738a.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Enhancing Maize Production in Mali: The Role of Fertilizer Microdosing and Mechanization in Improving Yield, Economic Returns, and Reducing Labor Use","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThere is an increased interest in maize production in the drylands of West Africa due to its high productivity, high fertilizer response, the release of extra-early varieties, and improved resistance to birds compared to other dryland cereal crops. Under typical farming conditions in West Africa, maize yields range from 1.5 to 2.5 tons per hectare, significantly outperforming traditional dryland crops like pearl millet and sorghum [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMaize was introduced to Mali during the French colonial era and was initially cultivated as a backyard crop on soils with good soil fertility [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Maize became popular as it could be harvested at a green stage before the ripening of other crops. There has been a significant increase in the area cultivated with maize in Mali over the past decades. In 1961, maize was cultivated on around 100,000 hectares, increasing to 1,500,000 hectares by 2022 [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Total maize production in the same period increased by about 40 times, and yield increased from 0.8 tons/ha to 2.6 tons/ha [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Maize production in Mali has surpassed that of pearl millet [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The rise in maize output is due to CMDT's (the Malian textile company) intensification efforts in the 1980s, promoting cotton-maize rotation in Southern Mali and providing access to fertilizers, improved seeds, and pesticides.\u003c/p\u003e \u003cp\u003eThe recommended fertilizer application rate is 100 kg NPK/ha as a basal dressing and 150 kg/ha of urea as a top dressing. However, due to limited access to fertilizers and financial constraints, many farmers have been unable to apply the recommended rate. Research conducted in other parts of Africa has found that microdosing, which involves applying small fertilizer quantities adjacent to the plant hill, is an efficient method for fertilizer application [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In Benin, the application of 23.8 kg N/ha and 4.1 kg P/ha (2 g NPK per hill) as microdosing increased maize yield by 64%, while the recommended rate of 76 kg N/ha and 13.1 kg P/ha increased yield by 93% [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe development of heat and drought-resistant, extra-early maize varieties that mature in just 80 to 90 days and require only 500 mm of rainfall has significantly increased maize production in the drylands [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Capitalizing on this progress, an IITA project on Climate Smart Agriculture has been actively promoting maize cultivation since 2018 in the drier regions north of Mali's cotton belt, where these varieties are particularly well-suited to thrive. Expanding maize to the north will mean that it will replace sorghum and, to some extent, millet.\u003c/p\u003e \u003cp\u003eHowever, maize is more labor-demanding to grow than the other dryland cereals because it is planted at a higher plant density (31,250 hills/ha) than sorghum (25,000 hills/ha). Therefore, promoting mechanized sowing, fertilizer application, and weeding is advantageous to ensure that seeds and fertilizers are placed at optimal density, depth, and rates. Experience from millet production in Mali shows that 14% higher yields can be expected when farmers practice mechanized sowing compared to manual sowing [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe objectives of this study were to identify optimal agronomic and economic microdosing rates in maize across a rainfall gradient and to assess the effects of mechanized sowing and fertilizer application on labor use in maize production.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cp\u003eThe study included two field trials: one to identify the response curve to increasing microdosing rates and another to assess the time use of mechanized seed and fertilizer application compared to manual operations.\u003c/p\u003e\n\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n\u003ch2\u003e2.1 Microdosing rates experiment\u003c/h2\u003e\n\u003cp\u003eThe field trials on increasing microdosing rates were established along a rainfall gradient. The field trials were conducted in the villages Kabo\u0026iuml;la in the Sikasso region, Sotuba (Regional Research Station) in Bamako, and Maf\u0026eacute;ya in the Koulikoro region. The sites can be characterized as follows:\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cp\u003eKabo\u0026iuml;la, Guinean zone, average rainfall 1000 mm\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eSotuba, Sudanian zone, average rainfall 800\u0026ndash;900 mm\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eMaf\u0026eacute;ya, border areas between Sudanian zone and Sudano-Sahelian zone, average rainfall 600\u0026ndash;700 mm\u003c/p\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eThe microdosing experiment was a randomized block trial with five replications at each site. Maize was sown at a row distance of 80 cm and an interrow spacing between hills of 40 cm, giving a planting density of 31,250 planting hills/ha. There were about two plants per hill. The maize variety used was Sotubaka, with a growth cycle of 120 days from sowing to maturity. The experimental plot size was 4.8 x 4.8 meters. Each plot had six rows, and the two central rows were harvested.\u003c/p\u003e\n\u003cp\u003eThe fertilizer treatments were as follows:\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cp\u003eNo fertilizer\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003e0.5 g fertilizer per hill, corresponding to 15.6 kg NPK/ha\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003e1 g fertilizer per hill, corresponding to 31.2 kg NPK/ha\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003e1.5 g fertilizer per hill, corresponding to 46.8 kg NPK/ha\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003e2 g fertilizer per hill, corresponding to 62.5 kg NPK/ha\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003e2.5 g fertilizer per hill, corresponding to 78.1 kg NPK/ha\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003e3 g fertilizer per hill, corresponding to 93,7 kg NPK/ha\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003e100 kg NPK/ha applied as row application\u003c/p\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eAll treatments received 50 kg urea/ha broadcasted at germination, followed by 100 kg urea/ha row applied at maize knee height. In the years 2022 and 2023, two urea treatments were introduced. In one treatment, the application of 75kg/ha urea was split in two: 25 kg urea/ha applied at sowing and 50 kg/ha at knee height, while in the second treatment, 150 kg urea /ha was used as in the first two years of the experiment.\u003c/p\u003e\n\u003cp\u003eTo evaluate the economic return of fertilizer application, we collected price data on grain, stover, and mineral fertilizer. According to FAOstat [\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e], maize farm gate prices ranged from 110 to 200 FCFA from 2020\u0026ndash;2023, with farmers reporting similar prices at maturity. An average price of 160 FCFA was used for this period, and 110 FCFA as the minimum price. Fertilizer (NPK 16-16-16) is priced at 500 FCFA/kg without a subsidy, but farmers typically access it at 250 FCFA/kg due to a 50% subsidy provided through CMDT. Straw was sold at an average of 40 FCFA/kg. For profitability analysis based on gross margin and Value-Cost Ratio (VCR), two scenarios were considered:\u003c/p\u003e\n\u003c/div\u003e\n\u003cp\u003e1. Regular scenario: grain at 160 FCFA/kg, fertilizer at 250 FCFA/kg, and stover at 40 FCFA/kg.\u003c/p\u003e\n\u003cp\u003e2. Worst-case scenario: grain at 110 FCFA/kg, fertilizer at 500 FCFA/kg, and stover at 40 FCFA/kg.\u003c/p\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n\u003ch2\u003e2.2 Effect of mechanization on time-use\u003c/h2\u003e\n\u003cp\u003eA trial was conducted to assess the effect of mechanization on time use and compare the yield of manually applied recommended fertilizer rates with reduced rates applied using planters (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). One of the planters tested was a modified version of the Super-ECO planter to which a fertilizer distribution unit was added. This allowed the simultaneous application of seeds and mineral fertilizer. The trial also included the Gangaria planter, a planter newly developed in Niger, that simultaneously applies seeds and organic fertilizer/compost in one operation [\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eThe treatments were as follows:\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cp\u003eManual sowing and manual application of 3.2 g NPK per planting hill (100 kg /ha)\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eUse of the double hopper Super-ECO planter to apply seeds and 1.5 g NPK per planting hill (46.8 kg/ha)\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eUse of the Gangaria planter for sowing and application of 50 g compost per hill (1.56 t /ha)\u003c/p\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eIn addition to the fertilizer applied in these treatments, each treatment also received 100 kg urea/ha row applied in two splits: 50 kg/ha 15 days after sowing and 50 kg/ha at knee height. Each plot measured 900 m\u0026sup2;, and yield was measured by harvesting ten randomly distributed one-square-meter quadrats in each plot. The test was conducted over four years, from 2020 to 2023.\u003c/p\u003e\n\u003cp\u003eLabor use was assessed by measuring the time required to complete the operation in each plot. The time-use in the manual treatment (treatment 1) included the work of three persons: one person opened a small planting pit, a second person placed the seed in the planting pit, and a third person added 3.2 g of fertilizer per planting pit. Two persons were used in mechanized sowing: one person steered the planter while the second person controlled the direction of the donkey. Labor use was converted into man-hours/ha.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n\u003ch2\u003e2.3 Statistical analyses\u003c/h2\u003e\n\u003cp\u003e\"The data were analyzed using analysis of variance (ANOVA), and means were separated using standard deviation and the Tukey test.\" JMP (version 17.2) was the statistical software used to analyze the data.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"3. Results","content":"\u003cp\u003eResults are presented on site conditions, the effect of increased microdosing rates on yield components, grain and stover yield, gross margin, value-cost ratio, and the impact of mechanization on time-saving and the yield effect of mechanized application combined with lower fertilizer rates.\u003c/p\u003e\n\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n\u003ch2\u003e3.1 Rainfall and soil properties at the experimental sites\u003c/h2\u003e\n\u003cp\u003eEven though the three sites were in different climatic zones, there were no major differences between them regarding average rainfall from 2020 to 2023 (Fig.\u0026nbsp;2). The average rainfall for the period at the sites Kabo\u0026iuml;la, Sotuba, and Maf\u0026eacute;ya was 824, 911, and 877 mm, respectively. The figure shows that rainfall was evenly distributed throughout the growing seasons at Sotuba and Maf\u0026eacute;ya. In contrast, Kabo\u0026iuml;la experienced greater variability between seasons and more frequent dry spells within the growing seasons.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003eThe soils at all three experimental sites were classified as loamy sand, and the soil properties did not differ significantly between the sites (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). The soils were sampled at the start of the experiment and at the end four years later, but no major changes in soil properties were observed. The soil fertility of these sites can be considered low, particularly due to the low levels of nitrogen, phosphorous, and potassium.\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eSoil chemical- and physical properties at Kabo\u0026iuml;la, Maf\u0026eacute;ya, and Sotuba sites.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eKabo\u0026iuml;la\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eMaf\u0026eacute;ya\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eSotuba\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eRating*\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\u003epH (water)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLow\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSOC%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.62\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\u003e0.56\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eVery low\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eN %\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.04\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\u003e0.04\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003every low\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eP-Bray\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLow\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eCEC meq/100g\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.50\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.44\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.41\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eVery low\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eCa meq/100g\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.44\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.34\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.36\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHigh\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eMg meq/100g\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHigh\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eK meq/100g\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.16\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\u003e0.11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLow-medium\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNa meq/100g\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.05\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLow\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSand %\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e65\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e66\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e68\u003c/p\u003e\n\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\u003eSilt %\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e27\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e26\u003c/p\u003e\n\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\u003eClay %\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e*Rating of soils based on Landon 1984.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n\u003ch2\u003e3.2 Agronomic effects of microdosing in maize\u003c/h2\u003e\n\u003cp\u003eThe agronomic effects of fertilizer were assessed based on the number of hills harvested per hectare and the number of cobs per hectare. There was no statistically significant effect of fertilizer rate on either of these variables. The average plant stand at harvest across the years and sites was approximately 28,948 hills per hectare, representing a plant stand of 92.6%. On average, there were about 44,000 cobs per hectare across the years and sites.\u003c/p\u003e\n\u003cp\u003eThe grain yield differed significantly among the three sites, with average grain yields of 2657 kg/ha for Kabo\u0026iuml;la, 2878 kg/ha for Sotuba, and 1303 kg/ha for Mafeya (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). No interaction was observed between sites and fertilizer rates, or years and fertilizer rates. The grain yield increased with increasing microdosing rates up to 93.7 kg NPK/ha, but there were only minor differences among the three highest microdosing rates and the differences were not statistically different. The good response to fertilizer in these trails was expected since nitrogen, phosphorous, and potassium levels were low in the soils.\u003c/p\u003e\n\u003cp\u003eYield increased from the control to the highest microdosing rate (93.7 kg/ha) by 1253 kg/ha in Kabo\u0026iuml;la, 936 kg/ha in Maf\u0026eacute;ya, and 897 kg/ha in Sotuba. The treatment of 100 kg NPK/ha, applied by row application, resulted in a lower yield than the highest microdosing rate, but this difference was not significant at any of the sites.\u003c/p\u003e\n\u003cp\u003eIncreasing microdosing rates significantly increased maize grain yield when summarized across four years and three sites (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). The five highest fertilizer rates produced a significantly higher yield than the control. The 93.7 kg NPK/ha rate also gave a significantly higher yield than 46.9 kg/ha and below. Applying 93.1 kg NPK/ha as microdosing increased yield by 1029 kg/ha compared to the control, representing a 61.3% increase in yield. This corresponds to a fertilizer use efficiency (FUE) of 11.4 kg per kg NPK. Application of the recommended dose of 100 kg NPK/ha gave a FUE of 7.88. The 62.5 kg NPK/ha microdosing rate produced a yield comparable to that achieved with a row application of 100 kg NPK/ha.\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n\u003ch2\u003e3.3 Straw yield and harvest index\u003c/h2\u003e\n\u003cp\u003eAs for grain yield, the straw yield increased significantly with increasing fertilizer rates (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). No interactions were found between site and fertilizer rates or between the years and the fertilizer rates. The 62.5 kg/ha fertilizer rate and above produced a significantly higher yield than the control. The highest yield was obtained with a microdosing rate of 78.1 kg NPK/ha, which increased straw yield by 1216 kg/ha compared to the control (45.3% increase ). The application of 62.5 kg NPK/ha as microdosing resulted in a yield similar to that of 100 kg NPK/ha applied by broadcasting.\u003c/p\u003e\n\u003cp\u003eThe fertilizer treatments did not significantly affect the harvest index. However, the harvest indexes in Maf\u0026eacute;ya, Kabo\u0026iuml;la, and Sotuba were 27.0, 53.7, and 40.4, respectively.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n\u003ch2\u003e3.4 Gross margin and Value-Cost-Ratio\u003c/h2\u003e\n\u003cp\u003eThe economic assessment was based on the gross margin and the value-cost ratio (VCR). The gross margin only included the costs that differed between the treatments, making it a partial gross margin analysis. Two scenarios were considered: one with regular grain prices and 50% subsidized fertilizer and a worst-case scenario with low grain prices and unsubsidized fertilizer. There was no interaction between location and fertilizer or year and fertilizer. Therefore, only the average results across sites and years are presented.\u003c/p\u003e\n\u003cp\u003eThere was a significant difference in gross margin between the treatments in both price scenarios (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e). The Tukey separation test showed that the 62.5, 78.1, 93.7, and 100 kg NPK/ha treatments had significantly higher gross margins than the control in both price scenarios. The treatment 78.1 had a gross margin that was only marginally lower than the 93.1 kg NPK treatment in the regular price scenario and produced the highest gross margin in the worst-case price scenario.\u003c/p\u003e\n\u003cp\u003eThe treatment 78.1 increased the gross margin compared to the control by 47.0% in the regular price scenario and 38.1% in the worst-case scenario. The application of 15.6 kg NPK/ha increased the gross margin by 19.8% compared to the control in the regular price scenario, but this increase was not significant. Row application of 100 kg NPK/ha resulted in a lower gross margin than the microdosing rates of 62.5 kg/ha in both price scenarios, but this difference was not significant.\u003c/p\u003e\n\u003cp\u003eFor the value-cost ratio (VCR), there were significant differences between the treatments in both scenarios, with the VCR exceeding the critical value of 2 in all scenarios and treatments (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e). The VCR was about 62% lower in the worst-case scenario than the regular price scenario. The highest VCR was obtained with the microdosing treatment of 15.6 kg NPK/ha, with a VCR of 20.1 in the regular price scenario and 7.5 in the worst-case scenario. The lowest VCR in both scenarios was obtained with the broadcasting treatment of 100 kg NPK/ha, yielding a VCR of 2.5 in the worst-case scenario.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n\u003ch2\u003e3.5 Effect of urea top-dressing\u003c/h2\u003e\n\u003cp\u003eThe urea application rates of 75 and 150 kg/ha were tested at all sites in 2022 and 2023. The urea application rates did not significantly affect the number of hills harvested per hectare, cobs harvested per hectare, or grain yield across the three sites and two years. Nor was there any significant interaction between these microdosing and urea rates on these variables.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTime-use and yield effect of mechanized application of seeds and fertilizer compared to manual operations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA three-year experiment was conducted at the Sotuba and Maf\u0026eacute;ya sites to evaluate the time efficiency and yield impact of three different methods: (1) manual sowing and manual application of 3.2 g NPK/hill corresponding to 100 kg NPK/ha (recommended rate), (2) using the donkey-drawn modified Super ECO planter to sow and apply about half the recommended fertilizer rate, and (3) using the donkey-drawn Gangaria planter to sow and apply 1.5 tons of compost per hectare. A significant difference in time-use was observed between manual sowing and the two mechanized sowing methods (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e). The average time-use for the manual operations was 11.3 man-days per hectare, compared to 0.95 man-days per hectare for the two mechanized operations. Mechanized sowing is, therefore, about 12 times faster than manual sowing. There was no significant difference in time-use between the two mechanized operations.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe yield levels in the time-use experiments corresponded with the results from the microdosing experiment, and the yield levels at the two sites were equal. The yield components, specifically the number of hills harvested per hectare and cobs harvested per hectare, differed significantly between the treatments (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The treatment with manual application of the recommended fertilizer rate performed better than the two mechanized treatments, particularly compared to the Gangaria planter with compost. The grain yield with the recommended fertilizer treatment was 29.3% higher than with the Gangaria planter and organic fertilizer, and 18.6% higher than with the Super-Eco planter and half the recommended application rate (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). Stover yield in the treatment using the recommended fertilizer rate was 35.0% higher than in the treatment with the use of the Gangaria planter and application of 1.5 tons of compost per hectare and 9.7% higher than in the treatment with the Super-Eco planter and a reduced fertilizer rate.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab2\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eEffect of mechanization and fertilizer application rate on no. harvested hills(ha, no. harvested cobs/ha, stover yield, and grain yield (different letters mean statistical differences based on the Tuckey test).\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eTreatment\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eNo. hills harvested/ha\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eNo. cobs harvested/ha\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eStover yield\u003c/p\u003e\n\u003cp\u003ekg/ha\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eGrain yield kg/ha\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\u003eManuel sowing\u0026thinsp;+\u0026thinsp;100 kg NPK/ha\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e24933\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e42952\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2776\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1768\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSuper eco planter\u0026thinsp;+\u0026thinsp;46.8 kg NPK/ha\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e22787\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e34793\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2530\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1490\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eGangaria planter\u0026thinsp;+\u0026thinsp;1.56 ton manure/ha\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e20836\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e31165\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2065\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1367\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eAverage\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e22852\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e36303\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2457\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1542\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSignificance\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.0005\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eThe discussion will focus on explaining maize's agronomic and economic performance at the three experimental sites. Additionally, we will explore how planters can reduce labour use.\u003c/p\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Effect on yield\u003c/h2\u003e \u003cp\u003eThe microdosing treatment with 93.7 kg NPK/ha performed the best at all sites, resulting in yield increases compared to the control at Kabo\u0026iuml;la, Sotuba, and Maf\u0026eacute;ya by 1252, 936, and 897 kg/ha, respectively. The response to microdosing was also good in Maf\u0026eacute;ya, despite its location north of the cotton belt. However, the harvest index in Maf\u0026eacute;ya was only 27.0%, compared to an average of 47.1% at Kabo\u0026iuml;la and Sotuba. The lower harvest index in Maf\u0026eacute;ya is hard to explain, as rainfall data shows no end-of-season drought in any of the years.\u003c/p\u003e \u003cp\u003eWhen the results were summarized across the years and sites, the grain yield increased with increasing microdosing rates up to 93.1 kg/ha (3 g NPK per planting hill). The four highest fertilizer rates resulted in significantly higher yields than the control. The fertilizer rate did not significantly influence the yield components, such as the number of harvested hills/ha and the number of cobs/ha. Therefore, the increase in grain yield with increasing fertilizer rate is likely due to more grains per cob and/or a higher kernel weight. The good response to fertilizer in these trails was expected since nitrogen, phosphorous, and potassium levels were low in the soil.\u003c/p\u003e \u003cp\u003eThe treatment of 93.1 kg NPK/ha increased grain yield compared to the control across the three sites on average by 1029 kg/ha (61.3% increase). The fertilizer use efficiency was 11.4 kg of grain per kg of fertilizer applied, representing a good response to fertilizer. The yield with 62.6 kg fertilizer/ha applied as microdosing matched that of 100 kg NPK/ha applied by row application, suggesting more efficient fertilizer use in microdosing.\u003c/p\u003e \u003cp\u003eThe highest stover yield was achieved when applying 78.1 kg NPK/ha as microdosing. This treatment increased stover yield by 1216 kg/ha (45.2%) compared to the control. The 93.7 kg NPK/ha rate increased maize grain yield by 61.3%, showing that fertilizer has a relatively better effect on grain yield than stover yield.\u003c/p\u003e \u003cp\u003eThe highest microdosing rate increased yield compared to the control by 1029 kg/ha, a fertilizer response beyond what has been observed in pearl millet and sorghum production in central and southern Mali [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. This suggests that if farmers cannot afford fertilizer for all their cereal crops, it is advisable to prioritize its use on maize.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Economic assessment\u003c/h2\u003e \u003cp\u003eThe gross margin and VCR analyses indicated that all the fertilizer rates tested are profitable. The 78.1 kg NPK/ha rate produced a gross marginally lower than 93.5 kg NPK/ha in the regular scenario, while it gave the highest gross margin in the worst-case scenario. The increase in gross margin between the control and the treatment 78.1kg NPK/ha in the regular price scenario was 176,789 FCFA (47.0% increase), while the corresponding increase in the worst-case scenario was 111,118 FCFA (38.1% increase). The difference in gross margin is moderate between the two scenarios, even though the ratio between fertilizer and grain was 4.5 in the worst-case scenario and 1.5 in the regular price scenario. Our study thus shows that fertilizer is profitable even under an unfavorable ratio between prices of fertilizer and grain.\u003c/p\u003e \u003cp\u003eThe VCR (value-cost ratio) in the treatment 78,1 was 8.7 in the regular price scenario, while this treatment produced a 3.9 in the worst-case scenario. Both values exceed the critical VCR threshold of two [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Despite the high gross margin, applying 100 kg NPK/ha by row application is risky, as shown by a VCR of 2.5 in the worst-case scenario. For resource-constrained farmers who can only purchase fertilizer in small quantities, applying 15.6 kg NPK/ha using microdosing can be an interesting alternative, as this rate gave a VCR of 20.1 in the regular scenario and increased the gross margin compared to the control by 74,545 FCFA/ha (20% increase).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e4.3 Mechanization of sowing and fertilizer application\u003c/h2\u003e \u003cp\u003ePlanting time is hectic for the farmers in central and southern Mali. To address this problem, the project developed a planter that can simultaneously apply seeds and mineral fertilizer. Mechanized sowing and microdosing, compared to manual application of seeds and manual microdosing, were found to save about 10 man-days/ha. The area under maize in the cotton belt is about 2.6 ha [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], implying that it would take about 26 additional days to do the work manually compared to using mechanization. Planters are, therefore, essential to ensure timely sowing and microdosing application.\u003c/p\u003e \u003cp\u003eYield was lower in the two treatments with mechanization compared to the recommended rates. This is likely due to the lower fertilizer rates used in these treatments. In the treatment with the Super-eco planter, 46 kg NPK/ha was used, resulting in an 18.6% lower yield than the recommended rate. This yield reduction in this treatment is equal to the yield reduction in the treatment with 46.8 kg NPK/ha in the microdosing study.\u003c/p\u003e \u003cp\u003eMechanized sowing and fertilizer application in maize is becoming increasingly important in Mali and other West African countries as the area under maize is rapidly expanding [14]. A previous study on mechanization in Mali [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] found that using a motorized planter is economically viable when the cereal cultivation area exceeds five hectares\u0026mdash;a condition met by many farmers in southern Mali.\u003c/p\u003e \u003cp\u003eThe current practice for maize sowing involves opening a small pit, placing the seeds in it, and then broadcasting fertilizer by hand. Farmers will not likely change from broadcasting/row application of fertilizer to manual microdosing because of the labor use associated with this method. Microdosing will become interesting if a planter is used to apply seeds and fertilizer simultaneously. Furthermore, utilizing planters will ensure that seeds and fertilizer are placed at an optimal depth, rate, and spacing.\u003c/p\u003e \u003c/div\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eThe economic analysis showed that the microdosing rate of 78.1kg NPK/ha is the best choice, as it gave a gross margin comparable to the 93.1 kg NPK/ha rate when using subsidized fertilizer and a better gross margin with unsubsidized fertilizer. However, the use of fertilizer, whether through microdosing or row application, is recommended, as the Value Cost Ratio (VCR) exceeded the critical threshold of 2 across all treatments. This holds true even in scenarios where only unsubsidized fertilizer is available and grain prices are low.\u003c/p\u003e \u003cp\u003eThe study also revealed that using a planter to apply seeds and fertilizer as microdosing saved ten days per hectare compared to the manual sowing and microdosing application. Farmers are not likely to change from fertilizer broadcasting/row application to mechanized application unless they get access to planters. In conclusion, the study demonstrated that using mineral fertilizer in maize cultivation remains viable even without subsidies. Mechanized fertilizer application is recommended to ensure timely operations and enhance fertilizer use efficiency.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eThis research was funded by the Norwegian Ministry of Foreign Affairs through the IITA project \u0026ldquo;Climate Smart Agricultural Technologies (CSAT).\u0026nbsp;The authors have no relevant financial or non-financial interests to disclose. \u0026nbsp;The data are publicly available.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEthical statement\u003c/p\u003e\n\u003cp\u003eThe species used in this experiment was maize (Zea mays (L.)) and is available in the herbarium of Royal Botanic Gardens, Kew, UK. \u0026nbsp;The herbarium \u0026nbsp;barcode number is K000632872.\u003c/p\u003e\n\u003cp\u003eThe maize variety used was the\u0026nbsp;Sotubaka, developed by the Maize Program of Institute d\u0026rsquo;Economie Rurale (IER) in Mali. The variety is listed in IER catalogue of recommended varieties and is widely used by the farmers in Mali. The research was undertaken in collaboration with the Maize Program of IER. The use of this variety complies with \u0026nbsp; national guidelines with no need for further affirmation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe research protocol of this study was approved by the Research Committee of IER, the Scientific Commission of Centre National de Research Agricole (CNRA) and by the director of the Climate Smart Agricultural Technologies (CSAT) program of International Institute of Tropical Agriculture (IITA). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAuthorship contribution: Conceptualization and methodology: [A. Coulibaly, K. Woumou, J.B. Aune], Conducting field trials [A. Couliblay, K.Woumou], Statistical analysis [A. Couliblay, K.Woumou, J.B. Aune], Graphics [J.B. Aune], Writing [A. Coulibaly, K. Woumou and J.B. Aune]\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFusillier JL (1994) Western Africa: maize or sorghum. Agriculture and Development-special issue. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://agritrop.cirad.fr/387424/1/document_387424.pdf\u003c/span\u003e\u003cspan address=\"https://agritrop.cirad.fr/387424/1/document_387424.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaris P, Foltz JD (2014) Cotton as Catalyst? The Role of Shifting Fertilizer in Mali\u0026rsquo;s Silent Maize Revolution. Hum Ecol 42, 857\u0026ndash;872. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10745-014-9694-0\u003c/span\u003e\u003cspan address=\"10.1007/s10745-014-9694-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFAOstat 2024. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.fao.org/statistics/en\u003c/span\u003e\u003cspan address=\"https://www.fao.org/statistics/en\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWiggins S, Allen M, Barry B, Mami E, Patel N, Sulieman H (2023) Food prices in Mali and Sudan: changes, causes, consequences and responses. London: SPARC. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.sparc-knowledge.org/sites/default/files/documents/resources/report-food-prices-in-mali-and-sudan.pdf\u003c/span\u003e\u003cspan address=\"https://www.sparc-knowledge.org/sites/default/files/documents/resources/report-food-prices-in-mali-and-sudan.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCoulibaly A, Woumou K, Aune JB (2019) Sustainable intensification of sorghum and pearl millet production by seed priming, seed treatment and fertilizer microdosing under different rainfall regimes in Mali. Agronomy 9:664. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/agronomy9100664\u003c/span\u003e\u003cspan address=\"10.3390/agronomy9100664\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTovihoudji PG, Irenikatch\u0026eacute; Akponikp\u0026egrave; PB, Agbossou EK, Bertin P, Bielders CL (2017) Fertilizer microdosing enhances maize yields but may exacerbate nutrient mining in maize cropping systems in northern Benin. Field Crops Res 213, 130\u0026ndash;142. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.fcr.2017.08.003\u003c/span\u003e\u003cspan address=\"10.1016/j.fcr.2017.08.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKonate L, Badu-Apraku B, Coulibaly M, Menkir A, Laouali MN, Meseka S, Mengesha W (2023) Agronomic performance and yield stability of extra-early maturing maize hybrids in multiple environments in the Sahel. Heliyon 9, e21659, \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.heliyon.2023.e21659\u003c/span\u003e\u003cspan address=\"10.1016/j.heliyon.2023.e21659\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWossen T, Menkir A, Alene A, Abdoulaye T, Ajala S, Badu-Apraku B, Gedil M, Mengesha W, Meseka 8 (2023) Drivers of transformation of the maize sector in Nigeria. Global Food Secur 38:100713. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.gfs.2023.100713\u003c/span\u003e\u003cspan address=\"10.1016/j.gfs.2023.100713\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAune JB, Coulibaly A, Woumou K (2019) Intensification of dryland farming in Mali through mechanisation of sowing, fertiliser application and weeding. Arch Agron Soil Sci 65:400\u0026ndash;410. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/03650340.2018.1505042\u003c/span\u003e\u003cspan address=\"10.1080/03650340.2018.1505042\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNourou AIM, Saidou AK, Aune JB (2020) Development and use of a planter for simultaneous application of seed, fertilizer and compost in pearl millet production in Niger\u0026mdash;effects on labor use, yield and economic return. Agronomy 10:1886. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/agronomy10121886\u003c/span\u003e\u003cspan address=\"10.3390/agronomy10121886\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLandon J (1984) Booker Tropical Soil Manual. Booker Agriculture Internation Limited, London, 450 p.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorris M, Kelly VA, Kopicki RJ, Byerlee D (2007) Fertilizer use in African agriculture: lessons learned and good practice guidelines. World Bank; Direction in Development-Agriculture and Rural Development, No. 39037. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://documents1.worldbank.org/curated/en/498591468204546593/pdf/390370AFR\u003c/span\u003e\u003cspan address=\"https://documents1.worldbank.org/curated/en/498591468204546593/pdf/390370AFR\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e0Fert101OFFICIAL0USE0ONLY1.pdf\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWesterberg V, Diarra A, Diallo H, Diallo S, Kone B, Domergues M, Keita O, Doku A, Di Falco SD (2020) The economics of cotton production in Mali and the challenges of land degradation. Case study in Koutiala and Bougouni. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.eld-initiative.org/fileadmin/Regreening_Africa_publications/ELD-Mali-Report-web-EN.pdf\u003c/span\u003e\u003cspan address=\"https://www.eld-initiative.org/fileadmin/Regreening_Africa_publications/ELD-Mali-Report-web-EN.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\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":"maize, microdosing, urea, mechanized sowing, economic assessment","lastPublishedDoi":"10.21203/rs.3.rs-5331059/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5331059/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe objectives of this study were to determine the optimal maize NPK microdosing rate in Mali and compare labor requirements for mechanized versus manual sowing and fertilization across three locations with varying rainfall. The treatments included five microdosing rates, ranging from zero to 93 kg NPK/ha (3 g NPK/hill), and the recommended rate of 100 kg NPK/ha applied by row application. All treatments also received an additional 150 kg urea/ha. Grain yield increased with application rates up to 93 kg/ha, resulting in a 1029 kg/ha (61.3%) increase compared to the control. The 63 kg NPK/ha microdosing rate resulted in a yield and economic return comparable to the application of 100 kg NPK/ha using row placement. The profitability of fertilizer use was evaluated by analyzing scenarios with both unfavorable and favorable ratios between fertilizer costs and grain prices. The 78.1 kg NPK/ha microdosing rate gave the highest average gross margin and VCR across the two price scenarios. The value-cost ratio was above the critical threshold of two in all fertilizer treatments, even under an unfavorable fertilizer-to-grain price ratio. Therefore, the risk associated with fertilizer use in maize is low, even if only non-subsidized fertilizer is available.\u003c/p\u003e \u003cp\u003eThe labour study showed that the manual application of seeds and microdosing of fertilizer averaged 11.4 man-days/ha, compared to 1.0 man-days/ha for the corresponding mechanized operation. Farmers will, therefore, not be likely to practice microdosing unless the operation is mechanized.\u003c/p\u003e","manuscriptTitle":"Enhancing Maize Production in Mali: The Role of Fertilizer Microdosing and Mechanization in Improving Yield, Economic Returns, and Reducing Labor Use","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-11-27 14:15:11","doi":"10.21203/rs.3.rs-5331059/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-11-28T09:57:11+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-27T11:16:25+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-20T14:30:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"55983912206244402406223702590754072602","date":"2024-11-17T12:44:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"67246180250367380041173282498561027953","date":"2024-11-14T13:10:17+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-11-14T08:20:29+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-11T09:21:57+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-11-09T09:12:25+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Agriculture","date":"2024-10-25T08:54:16+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":"7127708b-870a-4935-ae8b-010624dd20f8","owner":[],"postedDate":"November 27th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-03-11T11:53:37+00:00","versionOfRecord":[],"versionCreatedAt":"2024-11-27 14:15:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5331059","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5331059","identity":"rs-5331059","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}