Effects of Scattered Erythrina brucei Trees on Wheat Yield and Soil Physicochemical Properties in Bonke District, Gamo Zone, Southern Ethiopia

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The large amount of leaf litter it sheds during the dry season coupled with its rapid decomposition for the cropping season attracts farming family’s attention to retain in their farmland. Therefore, the current study was carried out with the aim of evaluating soil physico-chemical properties and wheat yield under scattered Erythrina brucei trees in farmland. Five trees on similar slope of land with relatively similar age, DBH (diameter at breast height), tree height, and canopy diameter were selected. The tree canopy diameter was divided into three distances: inner, middle and periphery. An open area at least double distance away from tree canopy was located for control. Soil samples at 0-30cm soil depth from three canopy distances and open control were taken for analysis of selected soil physico-chemical properties. Data were also recorded on growth, yield and yield attributes of wheat. The result of soil analysis revealed that with the exception of soil texture and soil pH, all soil properties increased significantly under Erythrina brucei canopy than in the open area showing a decreasing trend with increasing distance from the tree trunk. The result also indicated highest wheat yield at inner distance with yield increments of 18.17% compared to open control. We recommend optimal density of 100 Erythrina trees integration to enhance wheat yield in the study district and elsewhere with similar agroecology. Tree-crop interactions scattered trees Soil fertility Wheat yield Agroforestry Figures Figure 1 Figure 2 Introduction Soil nutrient degradation is considered as a major challenge in achieving food security and natural resource conservation in sub-Saharan African countries including Ethiopia (Sanchez and Swaminathan, 2005 ; Bationo et al., 2007 ). The loss of soil through erosion that deteriorates soil fertility, moisture storage capacity, and soil structure contributed to reduced agricultural productivity in Ethiopia (Bishaw, 2001 ). Agroforestry can be a viable option to alleviate the degradation and loss of soil fertility from the agricultural fields. According to Rosenstock et al. ( 2014 ) integration of legume trees into agricultural systems, therefore, adds biologically fixed nitrogen and other agriculturally important nutrients to the soil in a way that complements the crops grown in association with the trees (Akinnifesi et al., 2010 ). Agena ( 2009 ) stated that selecting tree and crop species with complementary patterns of light, water and nutrient acquisition can give higher overall system productivity than conventional agriculture or forestry and reduce leaching losses. Cultivating and use of trees like Erythrina brucei on farmlands in association with some important annual and perennial crops, such as barley, wheat, enset, apple and cabbage are a long tradition in many parts of Gamo highlands. Rapid establishment in the field, high rate of litter production, rapid litter decomposition, and other biological and physiological attributes of erythrina attracts farming families’ attention to incorporate in their agricultural lands. However, its interaction with associated crops in the farmland and its effects on soil physicochemical properties have not been scientifically quantified and documented in the study area. Therefore, the present study was initiated to evaluate effects of naturally retained Erythrina brucei trees on wheat yield and selected physico-chemical properties of the soil. Materials And Methods Study Area Description The study was conducted in Bonke district, Gamo Zone, Southern Nations, Nationalities and Peoples’ Region, Ethiopia. The district has a geographical location of between 6° 2'' 60' N and 37° 19'' 60' E latitude and longitude respectively. The district has a total population of 79,544, of which 47,726 are men and 31,818 women. The annual rainfall ranges from 1000 mm to 1400 mm; The minimum, maximum, and mean annual temperature of the area are 12°C, 19°C and 16°C, respectively(CSA Arba Minch branch,2021). Mixed crop-livestock farming is typical for the district. Main annual crops grown are barely, wheat, and potato. Besides this, some perennial crops grown in the area include enset, apple and cabbage. The dominant livestock in the study area are sheep, cattle, equines and chicken. Experimental Procedures, Treatments And Experimental Design Tree selection Mature erythrina trees above ten years old with similar diameter at breast height (DBH), height and canopy diameter were selected purposively to maintain uniformity of the experimental material and reduce extraneous effect while testing the study variables. Relatively homogenous site conditions in terms of slope, aspect and topography were also considered in the selection of the trees. The sample trees were marked and their DBH, height and crown diameter were measured by using caliper, clinometer and meter tape, respectively. Table 1 Selected morphological characteristics of Erythrina trees selected for the study Height(m) DBH (cm) Crown diameter(m) Max 18 68 14 Min 14 62 10 Mean ± SE 16.40 ± 0.81 65 ± 1.00 12.2 ± 0.80 Source: Field survey (2020) Treatments And Experimental Design The treatments consisted of four levels of crown distances (1/3 of three crown, 2/3 of the tree crown, edge of the tree crown and open field). The tree crown was first divided into three equal distances namely: 1/3 of the tree crown (inner distance), 2/3 of the crown (middle distance) and the edge of the tree crown (crown periphery) whereas the open field was considered as control for treatment companion (Agena et al ., 2014). Open fields were selected based on similarity in slop and aspect with the tree crown and vicinity to the tree crown (x m from the tree crown).Five similar trees of approximately equal age and canopy spread were considered for replication in randomized complete block design. Soil Sampling Three concentric circles were drawn under each tree crown at 1/3 crown radius, 2/3 crown radius and edge of the crown. Additionally, samples were also taken from the open control away from tree effect. Aiming for a representative soil sample, four sub-composite soil samples were taken by soil augur from 0–30 cm soil layer at each distance from four compass directions (North, South, East and West). Soil samples within the same radial distance were composited. The composited samples of 3 kg were properly labeled, and air-dried, ground and sieved through 2 mm sieve. Besides, separate soil samples were collected by using core sampler for soil bulk density. Land preparation and planting The land was ploughed with oxen and then harrowed twice by human labor. Sample plots of 1m x 1m were prepared from the three distances in four directions under the tree canopy all the experimental trees. Similar sample plots with size (1m x1m) were also prepared away from tree influence as control for comparison in five replications. Wheat variety “Hidase” was planted in spacing of 10cm x 20cm between plants and rows, respectively. Then, NPKS of the recommended rate was broadcasted evenly with wheat and then incorporated into the 0–20-cm soil depth after sowing. All other farmers’ agronomic practices were applied on wheat crop as per recommendations. Data Collection Procedures Data on days to 50% seedling emergence, days to 50% flowering, days to maturity, plant height and number of effective tillers per plant were collected. Yield attributing characteristics such as spike length and number of grains per spike were recorded from 5 randomly selected plants in each treatment plot. Thousand grain weight was measured after threshing and cleaning a random sample of grains from the produce of the sampling experimental plot. Biological yield and grain yield were estimated after harvest from plot and converted to kg/ha. Harvest index was calculated by dividing grain yield to biological yield and multiplying by 100. Soil Analysis Soil samples were analyzed for total nitrogen by Kjeldahl method (Jackson, 1958 ); available phosphorus (Olsen and Sommers, 1982); exchangeable K by ammonium acetate (Jackson, 1958 ); organic carbon (Walkley and Black, 1934 ), electrical conductivity and cation exchange capacity by (Houba et al., 1989 ); and pH, (1:2.5 soils to water ratio) by Jackson ( 1958 ). Texture was determined by hydrometer method (Gee and Bauder, 1982 ) and bulk density by the core method. Statistical analysis Two-way analysis of variance (ANOVA) was carried out to determine the effect of the treatments on the means of selected soil physicochemical properties, and wheat yield parameters through SAS software program (SAS, 2002) following the General Linear Model (GLM) procedure. Mean comparison was conducted by using the least significant difference (LSD) test at 5% level of significance. Results And Discussion Effects of E. brucei on Soil Physical Properties The results of soil textural analysis indicated that soil particle fractions of sand, silt and clay were not significantly varied with distance from the tree trunk whereas bulk density and moisture content were significantly influenced by the distance from the tree trunk (Table 2 ). According to Brady and Weil ( 2014 ), soil texture is an important physical property of soils that is not easily changed by humans as result of changes in land use. Our finding was in agreement with the report of Daniel et al. ( 2013 ) who found non-significant differences in the mean proportions of sand, silt and clay fractions between the soils under the canopies of F. thonninigii and in the open farmland in Ahferom district of Tigray, Ethiopia, and suggested that the soils had been derived from the same parent material. Table 2 Soil physical parameters as influenced by distance from the erythrina tree bole in Bonke district Parameter Treatment P-Value Textural fractions Inner distance Middle distance Periphery Control % Sand 22.68 ± 0.18 22.36 ± 0.31 22.12 ± 0.27 21.82 ± 0.11 NS % Silt 33.348 ± 0.18 33.09 ± 0.12 32.78 ± 0.15 32.54 ± 0.17 NS % Clay 45.78 ± 0.33 45.13 ± 0.37 44.86 ± 0.35 44.79 ± 0.22 NS Textural class Clay loam Clay loam Clay loam Clay loam BD (g cm-3) 1.14 ± 0.01 d 1.26 ± 0.01 c 1.34 ± 0.02 b 1.55 ± 0.01 a < 0.0001 % MC 26.918 ± 2.17 a 23.92 ± 0.21 ab 19.72 ± 0.26 bc 17.81 ± 0.28 c 0.005 Means along the rows with different superscripts are significantly different at p < 0.05. BD = Bulk density; MC = Moisture content; NS = non-significant Source: Lab result (2021) Bulk density significantly varied among distances from the tree trunk (p < 0.0001) and significantly increased with distance away from tree bole. The possible reason might be related to soil organic matter accumulation under canopy of the tree through litter fall. The result was in agreement with the finding of Hailie et al. ( 2019 ) who found higher bulk density in the open field than under the canopy of Ziziphus spina-christi tree in Habru District, North Wollo, Ethiopia. This results also revealed that soil moisture content was significantly affected (P = 0.005) by distances from the tree trunk. The highest (26.92%) and lowest (17.81%) moisture contents were recorded at inner distance and open field, respectively. This variation in soil moisture content under the tree canopy versus outside the canopy could be due to more organic matter contents which resulted in higher moisture retention potential of the soil under the tree canopy. Similar finding was reported by Desalegn and Zebene ( 2017 ) under Croton macrostachyus tree at Gemechis District of West Hararghe Zone. Effects of E. brucei on soil chemical properties Except soil pH, all the measured soil chemical properties were very highly significantly (p < 0.001) influenced by distance from tree trunk (Table 3 ).Although statistically not significant, pH was numerically decreased with increasing distance from inner tree trunk to open field. Findings of Agena et al . (2014) also reported no significant difference, but slightly neutral soil pH under B. aegyptiaca, A. tortilis and A. seyal in the central rift valley of Ethiopia. Soil electrical conductivity was significantly decreased with increase in distance from inner crown to open field as the maximum (0.44 ± 0.02) and minimum (0.26 ± 0.04) significant values were recorded from inner distance and control treatments, respectively. The reason might be due to the relatively higher leaf biomass which upon decomposition release soluble nutrients to the soil. In contrast to our finding, Gebrewahid et al (2019) reported no significant difference for soil electric conductivity under dispersed Oxytenanthera abyssinica and Dalbergia melanoxylon trees in semi-arid Ethiopia. Similarly, total was nitrogen decreased with increasing distance from the tree trunk. The result is in line with the finding of Hailie et at (2019) who found higher total soil nitrogen under the canopy of Ziziphus Spina-Christi in Habru District, North Wollo, Ethiopia. The highest organic carbon content was recorded at inner distance (2.60%), while the lowest value was recorded at the open control (1.89%). The higher organic carbon under canopy as compared to outside canopy could be due to the organic matter inputs from litter fall and decomposition. This finding is in line with Daniel et al ( 2013 ) who reported varied organic carbon of the soil under canopy of F. thonningii in Ahferom district of Tigray, Ethiopia. Table 3 Soil chemical parameters as influenced by distance from erythrina tree bole in Bonke district Parameter Treatment P-Value Inner distance Middle distance Periphery Control pH 6.69 ± 0.07 6.67 ± 0.09 6.57 ± 0.08 6.28 ± 0.09 NS EC (ds/m) 0.44 ± 0.02 a 0.38 ± 0.07 b 0.34 ± 0.07 b 0.26 ± 0.04 c < 0.0001 TN% 0.24 ± 0.03 a 0.20 ± 0.01 b 0.18 ± 0.01 c 0.15 ± 0.01 d < 0.0001 OC% 2.60 ± 0.09 a 2.36 ± 0.02 b 2.23 ± 0.07 b 1.89 ± 0.04 c 0.0007 CEC (cmol/kg) 32.56 ± 0.75 a 29.56 ± 0.56 b 27.84 ± 0.37 c 24.76 ± 0.53 d < 0.0001 AV. P(mg/kg) 9.46 ± 0.11 a 9.24 ± 0.07 ab 9.11 ± 0.06 b 7.98 ± 0.16 c < 0.0001 Exc K (cmol (+)/ kg 2.45 ± 0.03 a 2.38 ± 0.02 b 2.26 ± 0.02 c 1.80 ± 0.02 d < 0.0001 PH = Puissance de Hydrogen; EC = Electrical Conductivity; TN = Total Nitrogen; OC = Organic Carbon; CEC = Cation Exchange Capacity; AV. P = Available Phosphorus; EK = Exchangeable Potassium; NS = non-significant. Means along the same rows with different superscripts are significantly different at p < 0.05 Source: Lab result (2021) Mean value of CEC was significantly decreased with distance from the tree trunk (Table 3 ). The minimum (24.76 cmol/kg) and maximum (32.56 cmol/kg) value of cation exchange capacity were recorded at the open control and inner distance respectively. The possible reason could be the release of more cations to the soil from leaf litter decomposition and through mineralization resulting in increased negative charges in the soil. Available phosphorus was significantly (P < 0.0001) affected by distance from the tree trunk. It was significantly higher at inner distance, and there was a decreasing trend with increasing distance from the tree trunk towards the open area. The result also indicated that the concentrations of exchangeable potassium exhibited a decreasing trend with increasing distance from the erythrina tree trunk. This could be associated to the litter input under the trees and increased biological activities that enhance organic matter decomposition and subsequent mineralization, as reported by (Desalegn and Zebene, 2017 ). Effect of Erythrina brucei on Phenological attributes and plant height of wheat The study showed that there was no significant difference (p = 0.35) in the mean value of days to 50% seedling emergence. However, days to 50% flowering and maturity were significantly affected by distance from tree trunk (Table 4 ). The longest days to flowering were (103) and to maturity (170) were recorded from the inner distance from the tree trunk, while the shortest days to flowering were (90) and to maturity (140) were obtained from the open control. Our finding was similar to Mengsteab et al . (2018) who reported days to heading and maturity of sorghum decreased as the distance increased from the F. albida tree trunk. The analysis of variance also indicated that distance significantly affected (p = 0.042) the mean value of effective tiller number (NET) of wheat (Table 4 ). Significantly, the highest (375) ETN was obtained at the inner circle. The reason could be available organic material and decomposition. Different finding was reported by Alebel et al. ( 2022 ) who found that the average effective tiller number at a radial distance of 15m (79.7) and 6.0m (71.33) from the tree trunk was found at par but were significantly higher than that obtained at the radial distance of 1.5m (52.35) in Croton macrostachyus for Triticum aestivum in a parkland agroforestry system. Table 4 Phenological attributes of wheat influenced by distance from erythrina tree bole in Bonke district Parameters Treatment P-Value Inner distance Middle distance Periphery Control 50%DSE 18.60 ± 01.29 18.40 ± 01.21 18.40 ± 1.21 18.40 ± 1.08 NS 50%DF 103 ± 3.91 a 98.40 ± 3.33 ab 95 ± 2.55 bc 90 ± 2.41 c 0.0253 DM 170 ± 3.62 a 161 ± 2.98 ab 151 ± 3.76 b 140 ± 3.21 c 0.0024 NET /m 2 375 ± 6.67 a 359 ± 6.16 ab 351 ± 5.81 bc 336 ± 7.19 c 0.042 PH (cm) 109 ± 3.97 a 94.16 ± 2.59 b 89.04 ± 3.47 b 84.48 ± 2.29 b 0.0054 DSE = Days to Seedling Emergence, DF = Days to Flowering, DM = Days to Maturity, NET = Number of effective tillers, PH = Plant Height; NS = non-significant. Means along the same rows with different superscripts are significantly different at p < 0.05 Source: Field experiment (2021) The study showed that there was a significant difference (p = 0.0054) in the mean value of plant height (PH) due to distance from the tree trunk. The shortest plant (84.48cm) was recorded at control; while the tallest plant (109cm) was recorded at inner distance. Our finding is different from the report of Getahun et al. ( 2021 ) who found no significant height difference in maize and wheat under radial distance from Acacia albida tree. Effect of Erythrina brucei on yield and yield attributes of wheat The analysis of variance showed that distance significantly affected spike length (p = 0.042) and seed number per spike (p = 0.018). Statistically, the longest (10.44cm) and shortest (7.3cm) mean spikes were recorded from the inner distance and open control, respectively (Table 5 ). Highest mean spike length at the inner distance might be relatively higher leaf biomass and decomposition. Table 5 Yield and yield attributes of wheat as influenced by distance from erythrina tree bole in Bonke district Parameters Treatment Inner distance Middle distance Periphery Control P-Value SL (cm) 10.44 ± 0.78 a 9.3 ± 0.64 ab 8.46 ± 0.72 bc 7.3 ± 0.68 c 0.042 SNPS 80 ± 2.92 a 76 ± 3.10 ab 72 ± 2.81 bc 65 ± 2.63 c 0.018 TSW(g) 61.8 ± 2.38 a 55.7 ± 2.89 ab 51.2 ± 2.32 bc 47.06 ± 2.05 c 0.027 BY (kg) 7328 ± 47.39 a 6432 ± 178.13 b 5798.4 ± 148.79 c 4676.8 ± 266.27 d < 0.0001 GY (kg) 3455.4 ± 44.54 a 2788 ± 116.20 b 2289.6 ± 86.96 c 1638.2 ± 95.59 d < 0.0001 HI (%) 47.15 ± 0.39 a 43.28 ± 0.67 b 39.44 ± 0.54 c 35.06 ± 0.76 d < 0.0001 SL = Spike Length, SNPS = Seed Number per Spike, TSW = Thousand Seed Weight, BY = Biological Yield, GY = Grain Yield, HI = Harvest Index. Means along the same rows with different superscripts are significantly different at p < 0.05 Source: Field experiment (2021) As indicated in Table 5 , the mean value of seed number per spike (SNPS) was found to be highest at the inner distance (80), while the lowest was found in the control (65). The possible reason might be the longer spike length at the inner distance. Similarly, the highest (61.8g) and lowest (47.06g) thousand seed weight was obtained from the inner distance and the open control, respectively. The possible reason might be due to leaf and other falls near tree will add to the organic matter content of the soil by contributing organic biomass than open control. Contrary to our result reported by Alebel et al ( 2022 ) who found the highest TSW (42.33g) from a plot situated at 6.0m distant from the main trunk of the tree followed by that which was located 3.0m with a value of 38.73g. The present study indicated that biological and grain yields of wheat were significantly affected (p < 0.0001) due to distance from the tree trunk. The biological and grain yields of wheat significantly decreased as the distance from the tree trunk increased. The increase in grain yield near the tree could be due to the highest NET, highest spike length (SL) and highest TSW towards tree trunk than the open field. Our result is in agreement with Musa Abdella (2020) who found the highest values of sorghum grain yield (2089.51 and 1789.53 kg/ha) under F. albida and C. africana trees respectively at the distance of 2.50 m away from the tree trunks and these values decreased to 1459.40 and 1266.01 kg/ha under F. albida and C. africana respectively, at the distance of 25.0 m away from the tree trunks. Harvest index was also significantly affected (p < 0.0001) due to distance from the tree trunk and gave the maximum (47.15 ± 0.39) and minimum (35.06 ± 0.76) significant values due to inner distance and control/ open field, respectively (Table 5 ). This could be ascribed to favorable soil condition and better nutrient availability under tree canopy compared with open field resulting from litter fall which in turn improved growth and yield components leading to more translocation of resources to seed. Conclusion And Recommendation The study on the effect of Erythrina brucei trees on soil physico-chemical properties and yield of wheat in the farmland has revealed that soil moisture content, total nitrogen, organic carbon, available phosphorus, exchangeable potassium, electrical conductivity and cation exchange capacity have significantly increased and positively influenced by the trees under the canopy. On the other hand, the trees reduced soil bulk density and soil pH. But had no significant effect on soil texture. At the Erythrina and wheat interface, under the canopy, there was significant influence on all phenological attributes of wheat except days to seedling emergence. All yield attributes such as spike length, number of seeds per spike, thousand seed weight, biological yield and grain yield were significantly affected by distance of the tree. In general, Erythrina brucei tree in the study area had positive effect on physical and chemical soil properties, and wheat yield. Therefore, we recommend optimal density of 100 Erythrina trees integration to enhance wheat yield in the study district and elsewhere with similar agroecologies. Further research is also necessary to investigate comparative effect of erythrina tree on other dominant food crops. Declarations The authors have no any conflict of interests. Data Availability Statement This manuscript is extracted from the thematic research undertaken by the Department of Forestry, College of Agricultural Sciences, Arba Minch University. The data is available in the thematic research report of the college. A cknowledgement We are grateful to Arba Minch University for providing financial support for the accomplishment of this research work. Our Special thanks go also to Gamo Zone, Bonke District administrators, development agents and the community for their imaginative opinions and cooperation during the field work. References Agena A (2009). Component Interactions and Their Influence on the Production of Apple Based Agroforestry System in Wet Temperate Zone of Himachal Himalayas. Doctoral Thesis. Dr. Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan-173-230 (H.P.), India. Agena A, Tilahun Bekele L (2014). Effects of three tree species on microclimate and soil amelioration in the central rift valley of Ethiopia. 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International Journal of Environmental & Agriculture Research. 6, Issue-4. Olsen SR, Summer LE (1982). Methods of soil analysis; part 2. Chemical and microbiological properties of Phosphorus. ASA Monograph number. 9: 403–430. Rosenstock T, Tully K, Arias-Navarro C, Neufeldt H, Butterbach-Bahl K, Verchot L (2014). Agroforestry with N2-fixing trees: sustainable development’s friend or foe? Curr Opin Environ Sustain 6:15–21. Sanchez PA, Swaminathan M (2005). Hunger in Africa: the link between unhealthy people and unhealthy soils. Lancet 365:442–444. Walkley A, Black C (1934). Examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Sci., 37: 29–38. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies 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-2801514","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":190954037,"identity":"60add15c-5276-47e2-b2dc-559d2d7c6606","order_by":0,"name":"Aman Abeje","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7ElEQVRIiWNgGAWjYLACxgYGZgZm5gNApoQMCVrY2RJAWniI1sLAwM9jAGIT1sI/7fCzBz932LDzM/N8fnWjxoKHgf3w0Q34tEjcTjM37D2TxizZzLvNOucY0GE8aWk38FpzO8FMgrftMLPBYd5txjlsQC0SPGZ4tcjfTv8m+bftP7P9YZ5nxjn/iNBicDvHTJq37QCzATMP8+PcNiK0GN7OKZOWPZPMLHGYzYw5t0+Ch42QX+Rup2+TfLvDLpm///Djzznf6uT42Q8fw+99KEgGYjYJEIuNGOUgYAfEzB+IVT0KRsEoGAUjCwAA3SdCnjPgYEsAAAAASUVORK5CYII=","orcid":"","institution":"Arba Minch University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Aman","middleName":"","lastName":"Abeje","suffix":""},{"id":190954038,"identity":"87dfac6c-2f63-41e4-96ce-e050ef5d10b3","order_by":1,"name":"Mengistu Tumayro","email":"","orcid":"","institution":"Arba Minch University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Mengistu","middleName":"","lastName":"Tumayro","suffix":""},{"id":190954039,"identity":"8b99c782-7e16-41f7-b223-04c41e917221","order_by":2,"name":"Amare Girma","email":"","orcid":"","institution":"Arba Minch University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Amare","middleName":"","lastName":"Girma","suffix":""}],"badges":[],"createdAt":"2023-04-11 12:29:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2801514/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2801514/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":35786365,"identity":"71797097-dba2-4d89-94f0-8dd5290a0532","added_by":"auto","created_at":"2023-04-14 21:22:37","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":632329,"visible":true,"origin":"","legend":"\u003cp\u003eLocation map of the study area\u003c/p\u003e\n\u003cp\u003eSource: Aman Abeje (2021)\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2801514/v1/4ed086247bd87cce35646345.jpeg"},{"id":35786129,"identity":"2d1460e7-e7a2-4ebf-9bca-c9bfdc415829","added_by":"auto","created_at":"2023-04-14 21:14:37","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1277781,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eSoil sample collection at different canopy distances from the tree’s trunk\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ePhotos: Aman Abeje (2021)\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-2801514/v1/1dfdaae7c8312619d0fb210b.png"},{"id":36743529,"identity":"728d51d9-f2db-4e82-8226-10b5c75d14c5","added_by":"auto","created_at":"2023-05-09 13:44:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1687425,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2801514/v1/d63e0474-a513-4115-af9a-8bf6795ba0f1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effects of Scattered Erythrina brucei Trees on Wheat Yield and Soil Physicochemical Properties in Bonke District, Gamo Zone, Southern Ethiopia","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSoil nutrient degradation is considered as a major challenge in achieving food security and natural resource conservation in sub-Saharan African countries including Ethiopia (Sanchez and Swaminathan, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Bationo et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). The loss of soil through erosion that deteriorates soil fertility, moisture storage capacity, and soil structure contributed to reduced agricultural productivity in Ethiopia (Bishaw, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2001\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAgroforestry can be a viable option to alleviate the degradation and loss of soil fertility from the agricultural fields. According to Rosenstock et al. (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) integration of legume trees into agricultural systems, therefore, adds biologically fixed nitrogen and other agriculturally important nutrients to the soil in a way that complements the crops grown in association with the trees (Akinnifesi et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Agena (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) stated that selecting tree and crop species with complementary patterns of light, water and nutrient acquisition can give higher overall system productivity than conventional agriculture or forestry and reduce leaching losses. Cultivating and use of trees like \u003cem\u003eErythrina brucei\u003c/em\u003e on farmlands in association with some important annual and perennial crops, such as barley, wheat, enset, apple and cabbage are a long tradition in many parts of Gamo highlands. Rapid establishment in the field, high rate of litter production, rapid litter decomposition, and other biological and physiological attributes of erythrina attracts farming families\u0026rsquo; attention to incorporate in their agricultural lands. However, its interaction with associated crops in the farmland and its effects on soil physicochemical properties have not been scientifically quantified and documented in the study area. Therefore, the present study was initiated to evaluate effects of naturally retained \u003cem\u003eErythrina brucei\u003c/em\u003e trees on wheat yield and selected physico-chemical properties of the soil. \u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003ch3\u003eStudy Area Description\u003c/h3\u003e\n\u003cp\u003eThe study was conducted in Bonke district, Gamo Zone, Southern Nations, Nationalities and Peoples\u0026rsquo; Region, Ethiopia. The district has a geographical location of between 6\u0026deg; 2'' 60' N and 37\u0026deg; 19'' 60' E latitude and longitude respectively. The district has a total population of 79,544, of which 47,726 are men and 31,818 women. The annual rainfall ranges from 1000 mm to 1400 mm; The minimum, maximum, and mean annual temperature of the area are 12\u0026deg;C, 19\u0026deg;C and 16\u0026deg;C, respectively(CSA Arba Minch branch,2021). Mixed crop-livestock farming is typical for the district. Main annual crops grown are barely, wheat, and potato. Besides this, some perennial crops grown in the area include enset, apple and cabbage. The dominant livestock in the study area are sheep, cattle, equines and chicken.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ch3\u003eExperimental Procedures, Treatments And Experimental Design\u003c/h3\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n\u003ch2\u003eTree selection\u003c/h2\u003e\n\u003cp\u003eMature erythrina trees above ten years old with similar diameter at breast height (DBH), height and canopy diameter were selected purposively to maintain uniformity of the experimental material and reduce extraneous effect while testing the study variables. Relatively homogenous site conditions in terms of slope, aspect and topography were also considered in the selection of the trees. The sample trees were marked and their DBH, height and crown diameter were measured by using caliper, clinometer and meter tape, respectively.\u003c/p\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\u003eSelected morphological characteristics of Erythrina trees selected for the study\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\u003eHeight(m)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eDBH (cm)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eCrown diameter(m)\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\u003eMax\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e18\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\n\u003cp\u003e14\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eMin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e62\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SE\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.81\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e65\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.80\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003ctfoot\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"4\"\u003eSource: Field survey (2020)\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tfoot\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003ch3\u003eTreatments And Experimental Design\u003c/h3\u003e\n\u003cp\u003eThe treatments consisted of four levels of crown distances (1/3 of three crown, 2/3 of the tree crown, edge of the tree crown and open field). The tree crown was first divided into three equal distances namely: 1/3 of the tree crown (inner distance), 2/3 of the crown (middle distance) and the edge of the tree crown (crown periphery) whereas the open field was considered as control for treatment companion (Agena \u003cem\u003eet al\u003c/em\u003e., 2014). Open fields were selected based on similarity in slop and aspect with the tree crown and vicinity to the tree crown (x m from the tree crown).Five similar trees of approximately equal age and canopy spread were considered for replication in randomized complete block design.\u003c/p\u003e\n\u003ch3\u003eSoil Sampling\u003c/h3\u003e\n\u003cp\u003eThree concentric circles were drawn under each tree crown at 1/3 crown radius, 2/3 crown radius and edge of the crown. Additionally, samples were also taken from the open control away from tree effect. Aiming for a representative soil sample, four sub-composite soil samples were taken by soil augur from 0\u0026ndash;30 cm soil layer at each distance from four compass directions (North, South, East and West). Soil samples within the same radial distance were composited. The composited samples of 3 kg were properly labeled, and air-dried, ground and sieved through 2 mm sieve. Besides, separate soil samples were collected by using core sampler for soil bulk density.\u003c/p\u003e\n\u003ch3\u003eLand preparation and planting\u003c/h3\u003e\n\u003cp\u003eThe land was ploughed with oxen and then harrowed twice by human labor. Sample plots of 1m x 1m were prepared from the three distances in four directions under the tree canopy all the experimental trees. Similar sample plots with size (1m x1m) were also prepared away from tree influence as control for comparison in five replications. Wheat variety \u0026ldquo;Hidase\u0026rdquo; was planted in spacing of 10cm x 20cm between plants and rows, respectively. Then, NPKS of the recommended rate was broadcasted evenly with wheat and then incorporated into the 0\u0026ndash;20-cm soil depth after sowing. All other farmers\u0026rsquo; agronomic practices were applied on wheat crop as per recommendations.\u003c/p\u003e\n\u003ch3\u003eData Collection Procedures\u003c/h3\u003e\n\u003cp\u003eData on days to 50% seedling emergence, days to 50% flowering, days to maturity, plant height and number of effective tillers per plant were collected. Yield attributing characteristics such as spike length and number of grains per spike were recorded from 5 randomly selected plants in each treatment plot. Thousand grain weight was measured after threshing and cleaning a random sample of grains from the produce of the sampling experimental plot. Biological yield and grain yield were estimated after harvest from plot and converted to kg/ha. Harvest index was calculated by dividing grain yield to biological yield and multiplying by 100.\u003c/p\u003e\n\u003ch3\u003eSoil Analysis\u003c/h3\u003e\n\u003cp\u003eSoil samples were analyzed for total nitrogen by Kjeldahl method (Jackson, \u003cspan class=\"CitationRef\"\u003e1958\u003c/span\u003e); available phosphorus (Olsen and Sommers, 1982); exchangeable K by ammonium acetate (Jackson, \u003cspan class=\"CitationRef\"\u003e1958\u003c/span\u003e); organic carbon (Walkley and Black, \u003cspan class=\"CitationRef\"\u003e1934\u003c/span\u003e), electrical conductivity and cation exchange capacity by (Houba et al., \u003cspan class=\"CitationRef\"\u003e1989\u003c/span\u003e); and pH, (1:2.5 soils to water ratio) by Jackson (\u003cspan class=\"CitationRef\"\u003e1958\u003c/span\u003e). Texture was determined by hydrometer method (Gee and Bauder, \u003cspan class=\"CitationRef\"\u003e1982\u003c/span\u003e) and bulk density by the core method.\u003c/p\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n\u003ch2\u003eStatistical analysis\u003c/h2\u003e\n\u003cp\u003eTwo-way analysis of variance (ANOVA) was carried out to determine the effect of the treatments on the means of selected soil physicochemical properties, and wheat yield parameters through SAS software program (SAS, 2002) following the General Linear Model (GLM) procedure. Mean comparison was conducted by using the least significant difference (LSD) test at 5% level of significance.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results And Discussion","content":"\u003cp\u003e \u003cb\u003eEffects of\u003c/b\u003e \u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eE. brucei\u003c/span\u003e \u003cb\u003eon Soil Physical Properties\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe results of soil textural analysis indicated that soil particle fractions of sand, silt and clay were not significantly varied with distance from the tree trunk whereas bulk density and moisture content were significantly influenced by the distance from the tree trunk (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). According to Brady and Weil (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), soil texture is an important physical property of soils that is not easily changed by humans as result of changes in land use. Our finding was in agreement with the report of Daniel et al. (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) who found non-significant differences in the mean proportions of sand, silt and clay fractions between the soils under the canopies of \u003cem\u003eF. thonninigii\u003c/em\u003e and in the open farmland in Ahferom district of Tigray, Ethiopia, and suggested that the soils had been derived from the same parent material.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSoil physical parameters as influenced by distance from the erythrina tree bole in Bonke district\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP-Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTextural fractions\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInner distance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMiddle distance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePeriphery\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e% Sand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e% Silt\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.348\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32.78\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e32.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e% Clay\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45.78\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e44.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTextural class\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eClay loam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eClay loam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eClay loam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eClay loam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBD (g cm-3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e% MC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.918\u0026thinsp;\u0026plusmn;\u0026thinsp;2.17\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eMeans along the rows with different superscripts are significantly different at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. BD\u0026thinsp;=\u0026thinsp;Bulk density; MC\u0026thinsp;=\u0026thinsp;Moisture content; NS\u0026thinsp;=\u0026thinsp;non-significant\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eSource: Lab result (2021)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eBulk density significantly varied among distances from the tree trunk (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) and significantly increased with distance away from tree bole. The possible reason might be related to soil organic matter accumulation under canopy of the tree through litter fall. The result was in agreement with the finding of Hailie et al. (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) who found higher bulk density in the open field than under the canopy of \u003cem\u003eZiziphus spina-christi\u003c/em\u003e tree in Habru District, North Wollo, Ethiopia.\u003c/p\u003e \u003cp\u003eThis results also revealed that soil moisture content was significantly affected (P\u0026thinsp;=\u0026thinsp;0.005) by distances from the tree trunk. The highest (26.92%) and lowest (17.81%) moisture contents were recorded at inner distance and open field, respectively. This variation in soil moisture content under the tree canopy versus outside the canopy could be due to more organic matter contents which resulted in higher moisture retention potential of the soil under the tree canopy. Similar finding was reported by Desalegn and Zebene (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) under \u003cem\u003eCroton macrostachyus\u003c/em\u003e tree at Gemechis District of West Hararghe Zone.\u003c/p\u003e \u003cp\u003e \u003cb\u003eEffects of\u003c/b\u003e \u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eE. brucei\u003c/span\u003e \u003cb\u003eon soil chemical properties\u003c/b\u003e\u003c/p\u003e \u003cp\u003eExcept soil pH, all the measured soil chemical properties were very highly significantly (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) influenced by distance from tree trunk (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).Although statistically not significant, pH was numerically decreased with increasing distance from inner tree trunk to open field. Findings of Agena \u003cem\u003eet al\u003c/em\u003e. (2014) also reported no significant difference, but slightly neutral soil pH under \u003cem\u003eB. aegyptiaca, A. tortilis and A. seyal\u003c/em\u003e in the central rift valley of Ethiopia.\u003c/p\u003e \u003cp\u003eSoil electrical conductivity was significantly decreased with increase in distance from inner crown to open field as the maximum (0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02) and minimum (0.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04) significant values were recorded from inner distance and control treatments, respectively. The reason might be due to the relatively higher leaf biomass which upon decomposition release soluble nutrients to the soil. In contrast to our finding, Gebrewahid \u003cem\u003eet al\u003c/em\u003e (2019) reported no significant difference for soil electric conductivity under dispersed \u003cem\u003eOxytenanthera abyssinica\u003c/em\u003e and \u003cem\u003eDalbergia melanoxylon\u003c/em\u003e trees in semi-arid Ethiopia.\u003c/p\u003e \u003cp\u003eSimilarly, total was nitrogen decreased with increasing distance from the tree trunk. The result is in line with the finding of Hailie \u003cem\u003eet at\u003c/em\u003e (2019) who found higher total soil nitrogen under the canopy of \u003cem\u003eZiziphus Spina-Christi\u003c/em\u003e in Habru District, North Wollo, Ethiopia.\u003c/p\u003e \u003cp\u003eThe highest organic carbon content was recorded at inner distance (2.60%), while the lowest value was recorded at the open control (1.89%). The higher organic carbon under canopy as compared to outside canopy could be due to the organic matter inputs from litter fall and decomposition. This finding is in line with Daniel et al (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) who reported varied organic carbon of the soil under canopy of \u003cem\u003eF. thonningii\u003c/em\u003e in Ahferom district of Tigray, Ethiopia.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSoil chemical parameters as influenced by distance from erythrina tree bole in Bonke district\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP-Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInner distance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMiddle distance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePeriphery\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEC (ds/m)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTN%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOC%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.89\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCEC (cmol/kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e32.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.75\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.56\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e24.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.53\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAV. P(mg/kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eExc K (cmol (+)/ kg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003ePH\u0026thinsp;=\u0026thinsp;Puissance de Hydrogen; EC\u0026thinsp;=\u0026thinsp;Electrical Conductivity; TN\u0026thinsp;=\u0026thinsp;Total Nitrogen; OC\u0026thinsp;=\u0026thinsp;Organic Carbon; CEC\u0026thinsp;=\u0026thinsp;Cation Exchange Capacity; AV. P\u0026thinsp;=\u0026thinsp;Available Phosphorus; EK\u0026thinsp;=\u0026thinsp;Exchangeable Potassium; NS\u0026thinsp;=\u0026thinsp;non-significant. Means along the same rows with different superscripts are significantly different at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eSource: Lab result (2021)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eMean value of CEC was significantly decreased with distance from the tree trunk (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The minimum (24.76 cmol/kg) and maximum (32.56 cmol/kg) value of cation exchange capacity were recorded at the open control and inner distance respectively. The possible reason could be the release of more cations to the soil from leaf litter decomposition and through mineralization resulting in increased negative charges in the soil.\u003c/p\u003e \u003cp\u003eAvailable phosphorus was significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) affected by distance from the tree trunk. It was significantly higher at inner distance, and there was a decreasing trend with increasing distance from the tree trunk towards the open area. The result also indicated that the concentrations of exchangeable potassium exhibited a decreasing trend with increasing distance from the erythrina tree trunk. This could be associated to the litter input under the trees and increased biological activities that enhance organic matter decomposition and subsequent mineralization, as reported by (Desalegn and Zebene, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cb\u003eEffect of\u003c/b\u003e \u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eErythrina brucei\u003c/span\u003e \u003cb\u003eon Phenological attributes and plant height of wheat\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe study showed that there was no significant difference (p\u0026thinsp;=\u0026thinsp;0.35) in the mean value of days to 50% seedling emergence. However, days to 50% flowering and maturity were significantly affected by distance from tree trunk (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The longest days to flowering were (103) and to maturity (170) were recorded from the inner distance from the tree trunk, while the shortest days to flowering were (90) and to maturity (140) were obtained from the open control. Our finding was similar to Mengsteab \u003cem\u003eet al\u003c/em\u003e. (2018) who reported days to heading and maturity of sorghum decreased as the distance increased from the \u003cem\u003eF. albida\u003c/em\u003e tree trunk.\u003c/p\u003e \u003cp\u003eThe analysis of variance also indicated that distance significantly affected (p\u0026thinsp;=\u0026thinsp;0.042) the mean value of effective tiller number (NET) of wheat (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Significantly, the highest (375) ETN was obtained at the inner circle. The reason could be available organic material and decomposition. Different finding was reported by Alebel et al. (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) who found that the average effective tiller number at a radial distance of 15m (79.7) and 6.0m (71.33) from the tree trunk was found at par but were significantly higher than that obtained at the radial distance of 1.5m (52.35) in \u003cem\u003eCroton macrostachyus\u003c/em\u003e for \u003cem\u003eTriticum aestivum\u003c/em\u003e in a parkland agroforestry system.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePhenological attributes of wheat influenced by distance from erythrina tree bole in Bonke district\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eParameters\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP-Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInner distance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMiddle distance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePeriphery\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50%DSE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.60\u0026thinsp;\u0026plusmn;\u0026thinsp;01.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.40\u0026thinsp;\u0026plusmn;\u0026thinsp;01.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e18.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50%DF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e103\u0026thinsp;\u0026plusmn;\u0026thinsp;3.91\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e98.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.33\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e95\u0026thinsp;\u0026plusmn;\u0026thinsp;2.55\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e90\u0026thinsp;\u0026plusmn;\u0026thinsp;2.41\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0253\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e170\u0026thinsp;\u0026plusmn;\u0026thinsp;3.62\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e161\u0026thinsp;\u0026plusmn;\u0026thinsp;2.98\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e151\u0026thinsp;\u0026plusmn;\u0026thinsp;3.76\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e140\u0026thinsp;\u0026plusmn;\u0026thinsp;3.21\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0024\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNET /m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e375\u0026thinsp;\u0026plusmn;\u0026thinsp;6.67\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e359\u0026thinsp;\u0026plusmn;\u0026thinsp;6.16\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e351\u0026thinsp;\u0026plusmn;\u0026thinsp;5.81\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e336\u0026thinsp;\u0026plusmn;\u0026thinsp;7.19\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.042\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePH (cm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e109\u0026thinsp;\u0026plusmn;\u0026thinsp;3.97\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e94.16\u0026thinsp;\u0026plusmn;\u0026thinsp;2.59\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e89.04\u0026thinsp;\u0026plusmn;\u0026thinsp;3.47\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e84.48\u0026thinsp;\u0026plusmn;\u0026thinsp;2.29\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0054\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eDSE\u0026thinsp;=\u0026thinsp;Days to Seedling Emergence, DF\u0026thinsp;=\u0026thinsp;Days to Flowering, DM\u0026thinsp;=\u0026thinsp;Days to Maturity, NET\u0026thinsp;=\u0026thinsp;Number of effective tillers, PH\u0026thinsp;=\u0026thinsp;Plant Height; NS\u0026thinsp;=\u0026thinsp;non-significant. Means along the same rows with different superscripts are significantly different at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eSource: Field experiment (2021)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe study showed that there was a significant difference (p\u0026thinsp;=\u0026thinsp;0.0054) in the mean value of plant height (PH) due to distance from the tree trunk. The shortest plant (84.48cm) was recorded at control; while the tallest plant (109cm) was recorded at inner distance. Our finding is different from the report of Getahun et al. (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) who found no significant height difference in maize and wheat under radial distance from \u003cem\u003eAcacia albida\u003c/em\u003e tree.\u003c/p\u003e \u003cp\u003e \u003cb\u003eEffect of\u003c/b\u003e \u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eErythrina brucei\u003c/span\u003e \u003cb\u003eon yield and yield attributes of wheat\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe analysis of variance showed that distance significantly affected spike length (p\u0026thinsp;=\u0026thinsp;0.042) and seed number per spike (p\u0026thinsp;=\u0026thinsp;0.018). Statistically, the longest (10.44cm) and shortest (7.3cm) mean spikes were recorded from the inner distance and open control, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Highest mean spike length at the inner distance might be relatively higher leaf biomass and decomposition.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eYield and yield attributes of wheat as influenced by distance from erythrina tree bole in Bonke district\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameters\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInner distance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMiddle distance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePeriphery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP-Value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSL (cm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.64\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.042\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSNPS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80\u0026thinsp;\u0026plusmn;\u0026thinsp;2.92\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76\u0026thinsp;\u0026plusmn;\u0026thinsp;3.10\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e72\u0026thinsp;\u0026plusmn;\u0026thinsp;2.81\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e65\u0026thinsp;\u0026plusmn;\u0026thinsp;2.63\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.018\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTSW(g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.38\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2.89\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.32\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e47.06\u0026thinsp;\u0026plusmn;\u0026thinsp;2.05\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.027\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBY (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7328\u0026thinsp;\u0026plusmn;\u0026thinsp;47.39\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6432\u0026thinsp;\u0026plusmn;\u0026thinsp;178.13\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5798.4\u0026thinsp;\u0026plusmn;\u0026thinsp;148.79\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4676.8\u0026thinsp;\u0026plusmn;\u0026thinsp;266.27\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGY (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3455.4\u0026thinsp;\u0026plusmn;\u0026thinsp;44.54\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2788\u0026thinsp;\u0026plusmn;\u0026thinsp;116.20\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2289.6\u0026thinsp;\u0026plusmn;\u0026thinsp;86.96\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1638.2\u0026thinsp;\u0026plusmn;\u0026thinsp;95.59\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHI (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e47.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e39.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.54\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e35.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eSL\u0026thinsp;=\u0026thinsp;Spike Length, SNPS\u0026thinsp;=\u0026thinsp;Seed Number per Spike, TSW\u0026thinsp;=\u0026thinsp;Thousand Seed Weight, BY\u0026thinsp;=\u0026thinsp;Biological Yield, GY\u0026thinsp;=\u0026thinsp;Grain Yield, HI\u0026thinsp;=\u0026thinsp;Harvest Index. Means along the same rows with different superscripts are significantly different at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eSource: Field experiment (2021)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAs indicated in Table \u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, the mean value of seed number per spike (SNPS) was found to be highest at the inner distance (80), while the lowest was found in the control (65). The possible reason might be the longer spike length at the inner distance. Similarly, the highest (61.8g) and lowest (47.06g) thousand seed weight was obtained from the inner distance and the open control, respectively. The possible reason might be due to leaf and other falls near tree will add to the organic matter content of the soil by contributing organic biomass than open control. Contrary to our result reported by Alebel et al (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) who found the highest TSW (42.33g) from a plot situated at 6.0m distant from the main trunk of the tree followed by that which was located 3.0m with a value of 38.73g.\u003c/p\u003e \u003cp\u003eThe present study indicated that biological and grain yields of wheat were significantly affected (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) due to distance from the tree trunk. The biological and grain yields of wheat significantly decreased as the distance from the tree trunk increased. The increase in grain yield near the tree could be due to the highest NET, highest spike length (SL) and highest TSW towards tree trunk than the open field. Our result is in agreement with Musa Abdella (2020) who found the highest values of sorghum grain yield (2089.51 and 1789.53 kg/ha) under \u003cem\u003eF. albida\u003c/em\u003e and \u003cem\u003eC. africana\u003c/em\u003e trees respectively at the distance of 2.50 m away from the tree trunks and these values decreased to 1459.40 and 1266.01 kg/ha under \u003cem\u003eF. albida\u003c/em\u003e and \u003cem\u003eC. africana\u003c/em\u003e respectively, at the distance of 25.0 m away from the tree trunks. Harvest index was also significantly affected (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) due to distance from the tree trunk and gave the maximum (47.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39) and minimum (35.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76) significant values due to inner distance and control/ open field, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). This could be ascribed to favorable soil condition and better nutrient availability under tree canopy compared with open field resulting from litter fall which in turn improved growth and yield components leading to more translocation of resources to seed.\u003c/p\u003e"},{"header":"Conclusion And Recommendation","content":"\u003cp\u003eThe study on the effect of \u003cem\u003eErythrina brucei\u003c/em\u003e trees on soil physico-chemical properties and yield of wheat in the farmland has revealed that soil moisture content, total nitrogen, organic carbon, available phosphorus, exchangeable potassium, electrical conductivity and cation exchange capacity have significantly increased and positively influenced by the trees under the canopy. On the other hand, the trees reduced soil bulk density and soil pH. But had no significant effect on soil texture. At the Erythrina and wheat interface, under the canopy, there was significant influence on all phenological attributes of wheat except days to seedling emergence. All yield attributes such as spike length, number of seeds per spike, thousand seed weight, biological yield and grain yield were significantly affected by distance of the tree. In general, \u003cem\u003eErythrina brucei\u003c/em\u003e tree in the study area had positive effect on physical and chemical soil properties, and wheat yield. Therefore, we recommend optimal density of 100 Erythrina trees integration to enhance wheat yield in the study district and elsewhere with similar agroecologies. Further research is also necessary to investigate comparative effect of erythrina tree on other dominant food crops.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eThe authors have no any conflict of interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis manuscript is extracted from the thematic research undertaken by the Department of Forestry, College of Agricultural Sciences, Arba Minch University. The data is available in the thematic research report of the college.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003e\u003cstrong\u003ecknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe are grateful to Arba Minch University for providing financial support for the accomplishment of this research work. Our Special thanks go also to Gamo Zone, Bonke District administrators, development agents and the community for their imaginative opinions and cooperation during the field work.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAgena A (2009). Component Interactions and Their Influence on the Production of Apple Based Agroforestry System in Wet Temperate Zone of Himachal Himalayas. Doctoral Thesis. Dr. Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan-173-230 (H.P.), India.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAgena A, Tilahun Bekele L (2014). Effects of three tree species on microclimate and soil amelioration in the central rift valley of Ethiopia. Journal of Soil Science and Environmental Management. 5(5):62\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAkinnifesi FK, Ajayi OC, Sileshi G, Chirwa PW, Chianu J (2010). 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Plant and Soil Analysis procedures. Department of Soil Science and Plant Nutrition Agric. Univ. Wageningen, the Netherlands.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJackson ML (1958). Soil Chemical Analysis. Prentice; Halls, Inc., Englewood cliffs, New Jorsey. Sixth printing. p.\u0026nbsp;498.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMusa A (2020). Sorghum Yield Under the Canopies of \u003cem\u003eFaidherbia Albida\u003c/em\u003e (Delile) A. Chev and \u003cem\u003eCordia africana\u003c/em\u003e Lam Parkland Trees in Fedis District, Eastern Ethiopia. International Journal of Environmental \u0026amp; Agriculture Research. 6, Issue-4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOlsen SR, Summer LE (1982). Methods of soil analysis; part 2. Chemical and microbiological properties of Phosphorus. ASA Monograph number. 9: 403\u0026ndash;430.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRosenstock T, Tully K, Arias-Navarro C, Neufeldt H, Butterbach-Bahl K, Verchot L (2014). Agroforestry with N2-fixing trees: sustainable development\u0026rsquo;s friend or foe? Curr Opin Environ Sustain 6:15\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSanchez PA, Swaminathan M (2005). Hunger in Africa: the link between unhealthy people and unhealthy soils. Lancet 365:442\u0026ndash;444.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalkley A, Black C (1934). Examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Sci., 37: 29\u0026ndash;38.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Tree-crop interactions, scattered trees, Soil fertility, Wheat yield, Agroforestry","lastPublishedDoi":"10.21203/rs.3.rs-2801514/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2801514/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eErythrina brucei is multipurpose farm tree in Bonke district, Gamo Zone, Southern Region. The large amount of leaf litter it sheds during the dry season coupled with its rapid decomposition for the cropping season attracts farming family’s attention to retain in their farmland. Therefore, the current study was carried out with the aim of evaluating soil physico-chemical properties and wheat yield under scattered Erythrina brucei trees in farmland. Five trees on similar slope of land with relatively similar age, DBH (diameter at breast height), tree height, and canopy diameter were selected. The tree canopy diameter was divided into three distances: inner, middle and periphery. An open area at least double distance away from tree canopy was located for control. Soil samples at 0-30cm soil depth from three canopy distances and open control were taken for analysis of selected soil physico-chemical properties. Data were also recorded on growth, yield and yield attributes of wheat. The result of soil analysis revealed that with the exception of soil texture and soil pH, all soil properties increased significantly under Erythrina brucei canopy than in the open area showing a decreasing trend with increasing distance from the tree trunk. The result also indicated highest wheat yield at inner distance with yield increments of 18.17% compared to open control. We recommend optimal density of 100 Erythrina trees integration to enhance wheat yield in the study district and elsewhere with similar agroecology.\u003c/p\u003e","manuscriptTitle":"Effects of Scattered Erythrina brucei Trees on Wheat Yield and Soil Physicochemical Properties in Bonke District, Gamo Zone, Southern Ethiopia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-04-14 21:14:32","doi":"10.21203/rs.3.rs-2801514/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"440e8992-59e2-456a-9d99-f078db2443d4","owner":[],"postedDate":"April 14th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2023-05-09T13:44:34+00:00","versionOfRecord":[],"versionCreatedAt":"2023-04-14 21:14:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-2801514","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2801514","identity":"rs-2801514","version":["v1"]},"buildId":"GqpaHPwrfC8PjnIFayRh5","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}