Assessing the suitability of Kabanyolo soils for soybean production
Abstract
Land suitability normally refers to the process of estimating the fitness of a given piece of land for alternative agricultural uses. Land suitability analysis for soybean also referred to as Glycine max (L.) Merr helps farmers in decision making to enhance sustainable land use. Soybean is one of the most valuable crop grown worldwide capable of generating income for households and also considered as a highly nutritious crop that can to overcome high levels of hunger and malnutrition. Despite the benefits associated with growing soybean, its production is limited by many factors that include decline in soil fertility, climate change and also inadequate suitability information. The objectives of this study were (i) to determine the suitability of Kabanyolo soils for soybean production. The experiment was carried out in MUARIK (Makerere University Agriculture Research Institute Kabanyolo) Using the zigzag method, soil samples were collected at a depth between 0 - 30 cm using a hand hoe. A total of 30 samples per block were taken, mixed thoroughly and reduced by quartering to about a 1 kg composite sample for each block Cropland, Farmland and Grassland. A total of 30 composite samples were taken to the laboratory for analysis.
Soil reaction, available phosphorous, pH, soil organic matter, SOC, soil texture and exchangeable bases (Ca, K and Na) were assessed and entered in an excel spreadsheet and data was analysis using Gen Stat Statistical software and using the LSD at 5% probability was used to obtain the means of variance and standard error. Forestland was rated moderately suitable for soybean production due to the presence of high organic carbon (5.5ppm), high total nitrogen (0.27%), moderate texture and pH 5.26 important for soybean production. Grassland soils were marginally suitable (S3) for soybean production characterized of moderate SOC (2.12%) content, total nitrogen (0.19%) and pH (4.87) and moderately fine textured clayey soils. Cropland soils were also rated marginally suitable (S3) for soybean production. Since they were characterized of moderate Soil Organic Carbon (2.20%) and total nitrogen levels (0.17), pH 5.12 and higher clay. Exchangeable bases and texture were highly limiting for soybean production in all the three arable lands. However proper soil management practices such as liming, application of phosphate fertilizers alongside other soil management practices could help improve the soil quality.