Changes In Soil Properties Under Alley Cropping System Of Three Leguminous Crops

A study to evaluate the changes in soil properties, under existing alley cropping system with three leguminous crops ( Leucaena leucocephala, Gliricidia sepium, and Cajanus cajan ) was conducted in the experimental farm of the Faculty of Agriculture and Natural Resources Management, Ebonyi State University, Abakaliki between 2003-2005. The study was established in a randomized complete block design with five treatments consisting of 10 t ha -1 each of L. leucocephala, G. sepium and C. cajan prunings, 300kg ha -1 of 20:10:10 and a control with no amendments. The study was replicated four times. Soil pH increased from pH 4.2 (strongly acid) in the pre- planting to pH 6.1 (slightly acid) in C. cajan alley plots. The organic matter increased from 1.01g kg -1 in the pre-planting to 5.98g kg -1 in the C. cajan alley plots in 2005. Total N increased in all the alley plots with the highest N content of 2.31g kg -1 in the G. sepium alley plots, which was 68% in 2003, 90% in 2004 and 95% in 2005 over the pre-planting. Available P and exchangeable Ca and Mg increased significantly (p<0.05) in the alley plots over the pre-planting. The ECEC increased in line with exchangeable bases. Total acidity and Al3+ saturation were very low in the alley plots.