Evaluation of nutrient distribution across different enterprises at Makerere University Agricultural Research Institute Kabanyolo South, Central Uganda

Abstract

In agricultural farming systems, nutrient supplies to crop plants are sustained through recycling and management of biologically related processes such as nitrogen fixation by legumes and this is aimed at achieving as far as possible a closed nutrient cycle at the farm and to minimize adverse environmental impacts. Effective crop residue management as well as livestock management are a key to nutrient cycling on the agricultural fields through regulation of nutrient flows but the current market in which food is transported enhances large distances from the farm resulting in a significant export of nutrients, these nutrients must be replaced otherwise the agricultural field soils are impoverished and system un sustainable. Therefore, to cater for the rapidly growing population in sub Saharan Africa that puts great demand on agricultural production systems, farm management practices that balance both food and environmental objectives should be promoted and putting emphasis on farm management strategies that tighten nutrient cycles and maintain yields. However, there is limited understanding of nutrient cycling among the different farming enterprises at MUARIK. This study was therefore aimed at evaluation of nutrient distribution across different enterprises at MUARIK south central Uganda by determining the quantity of nutrient stocks, concentration and assessing the relative importance of different organic materials across different enterprises. The study was arranged in a Randomized Complete Block Design (RCBD) with enterprise as a basis for blocking, manure and plant parts across different enterprises were analyzed for chemical properties such as N, P, K and Ca. Data were analyzed using the GenStat statistical package 15th edition. There was a significant impact of enterprise on N, P, K and Ca in the different organic materials at MUARIK. The highest % N (3.26 ± 0.10) % was observed in broiler manure while the lowest % N content (0.56±0.05) % was observed in cattle manure. Similarly, the highest total K content (3.75±0.16) % in broiler manure was not significantly higher than that observed in layer manure (3.48±0.22) %. Surprisingly the percentage calcium content observed in pig manure was not significantly different from the percentage calcium content observed in maize Stover and maize grain; therefore, further studies are needed to establish why calcium content in pig manure is not significantly different from that observed in maize Stover and maize grain. N, P, K and Ca stocks were highest in banana fingers and cattle manure and lowest in banana rachis. Clearly results from this study indicate that broiler manure has the highest concentration of nitrogen and potassium therefore care should be taken in terms of storage, management and ploughed in soils.