Effect of crop-residue incorporation load on nitrogen require- ment of succeeding crops and soil productivity in rice (Oryza sativa) -wheat (Triticum aestivum) system

Abstract

A field experiment was conducted during 1992-93 to 1994-95 to investigate the effect of incorporation of variable crop residue loads of combine harvested rice (Oryza sativa L.) and wheat (Triticum aestivum L. emend. Fiori & Paol.) crops on the nitro- gen requirement of succeeding crops of wheat and rice grown in sequence and soil productivity. The treatments consisted of 3 levels of residue loads in the main plots and 3 of nitrogen (80,120,100 kg Nlha) in the subplots. The crop sequence of wheat followed by rice was taken for 3 years on the same site. An increasing trend was noted in crop yield and productivity with the increase in the level of residue load incorporated. The incorporation of moderate level of crop residue load in conjunction with the application of recommended level of N (120 kglha) not only assisted in increasing the grain yield but also increased the organic matter content, available N and P.