Influence of Cropping System and Residue Management on Selected Soil Chemical Properties

Declining soil fertility in sub-Saharan Africa caused by continuous cropping without nutrient inputs has resulted in declining crop yield. The study was aimed to determine the effects of crop rotation and crop residue management on soil pH, organic carbon, nitrogen and available soil P. A split plot experimental design was set up with crop management system (maize monocropping and maize –bean rotation) as main plots and crop residue (maize stover) as sub plots, in three consecutive cropping seasons. At planting, all plots received 60 kg of P2O5/ha and 60 kg of K2O/ha. Results for the three cropping seasons indicated slight decrease in soil acidity, (5.42±.11), increase in soil organic carbon (2.39±.40) and soil total nitrogen from the initial value of 0.15% to 0.22±.03 due to legume rotation. Available soil P improved from 2.99 to 8.65±1.63 cmol kg-1showing significant differences (P≤0.05) under rotation system plus addition of crop residue. Rotation of maize and legumes with crop residue addition is recommended for farmers, which will benefit them in improving soil fertility.