Effect of Applying Organic Amendments and Chick pea Integration on Soil Chemical Properties in Different Cropping Systems In Central Kenya

Abstract

A study was carried out to determine the effect of applying farm yard manure (FYM) and Minjingu rock phosphate (MRP) on soil available nitrogen, phosphorus and organic carbon. The study involved field experiments under varying precipitation pattern, soil fertility levels and cropping systems over four growth seasons.Theexperimentaldesignwasarandomized completeblock(RCBD)withfourreplicationsinasplitplot arrangement where the main plots were the three cropping systems; monocropping, intercropping and crop rotation and the split plots were FYM and MRPand sampling done at crop physiological maturity. Soil pH, N, P K and C increased in the different treatments in the following order control < MRP< FYM in the three cropping systemsacrossthefourgrowingseasonsatbothsites.In maizeunderrotationwithchickpeacontrolhad;0.281% N,2.82%Cand10.68ppmP.FYM;0.554%N,4.41%Cand18.24ppmP.MRP;0.45%N,3.6%Cand41.08 ppm P.Maizechickpeaintercropcontrol;0.389%N,3.192%Cand13.4ppmP.FYM;0.531%N,4.98%Cand 41.02 ppm P. MRP; 0.49% N, 4.08% C and 50.9 ppm P. Soil under maize monocrop exhibited; control; 0.2% N, 2.59%Cand11.26ppmP.FYM;0.416%N,3.83%Cand18.01ppmP.MRP;0.28%N,3.13%Cand26.1ppmP. Almost a similar trend was observed in maize and tomato plots at both sites in all the growing seasons. Thus it can be deduced that, FYM and MRP application and legume integration in cropping systems improves soil fertility.