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

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.