Effect of mulching and graded doses of fertilizer on yield and nutrient uptake of greater yam + maize intercropping system

Abstract

A field experiment was conducted for consecutive three years from 2003-04 to 2005-06 in acid laterite soil under rainfed conditions to find out the effect of mulching and graded doses of fertilizer on yield and nutrient uptake of greater yam + maize intercropping system. Conspicuous increase in yield of greater yam (21.0%) and maize (10.3%) was observed with the application of 2/ha dried farm waste as mulch. Increasing the doses of fertilizer increased the tuber and grain yield of greater yam and maize respectively. Application of 150% recommended dose of fertilizer of greater yam (N:P:K @ 120:90:120 kg/ha) recorded 65.7%, 26.0% and 4.4% higher greater yam tuber yield and 21.5%, 7.6% and 1.8% maize grain yield over 75%, 100% and 125% recommended dose of fertilizer of greater yam respectively. Greater yam tuber yield and maize grain yield with the application of 125% recommended dose of fertilizer of greater yam (N:P:K @ 100:75:100 kg/ha) along with mulching (2 t/ha) was significantly higher than the application of 150% recommended dose of fertilizer of greater yam (N:P:K @ 120:90:120 kg/ha). This indicated that under mulching about 25% recommended dose of fertilizer could be saved. Mulching increased 20.6% N, 25.9% P and 20.3% K higher uptake than no mulching in greater yam + maize intercropping system. Increased availability of mineral nutrition in mulched field due to favourable hydrothermal regimes in rhizosphere along with mineralization of mulched materials was responsible for this higher uptake.