Intercropping System, Rhizobia Inoculation, Phosphorus and Potassium Fertilization: A Strategy of Soil Replenishment for Improved Crop Yield

Abstract

The significant constraint to legumes and cereal crop production in most sub- Saharan Africa countries is the loss of soil fertility. The most limiting soil nutrients are nitrogen (N), phosphorus (P) and potassium (K) which to the great extent cause low grain yields. The main reason for declining of these nutrients in the soil is the mining through continued cultivation without external input application. These nutrients are not usually applied by farmers because of their high prices leading to poor crop growth, development and finally poor yield. Leguminous crops have ability to form symbiotic relationship with rhizobia and fix atmospheric nitrogen. The fixed nitrogen can be used by legume plant themselves or might be transferred and be utilized by other plants growing nearby in intercropping systems or can be used by plants grown in the subsequent season. This review focus on understanding how rhizobia inoculation, intercropping system, and fertilization with P and K influences nitrogen fixation; mineral composition in the crop rhizosphere; nutrient uptake in plants; plant growth; photosynthesis and leaf chlorophyll formation; land equivalent ratio and ultimately yield performance of legumes and cereals. The results from different literatures cited showed that rhizobia inoculation and supplementation with phosphorus and potassium had positive significant effects on all parameters measured. Therefore, based on the findings reported, it can be recommended, to use rhizobia inoculants supplemented with optimum levels of phosphorus and potassium in intercropping systems as a strategy for improving crop production.