Dynamics of N, P and K in Rice-Groundnut Cropping System as Influenced by Crop Residue Incorporation and Nitrogen Management Practices

Field experiments were conducted in the wetland farm of S.V. Agricultural College, Tripati (Acharya N.G. Ranga Agricultural University), Andhra Pradesh for two consecutive years 2002 - 2003 and 2003 - 2004 and results revealed that regardless of the preceding crops tried for incorporation of crop residues prior to rice. Nitrogen management practice of substituting 100 per cent of recommended dose of nitrogen through FYM to rice has resulted in build up of soil fertility status in terms of organic carbon. availahle N, P and K after entire cropping system. By raising a reasonably short duration leguminous crop (either a pulse crop or vegetable crop depending up on the farming situation) preceding to rice and incorporation of the crop residues after picking the economic yield and supply of 50 per cent recommended dose of nitrogen each through fertil izer and FYM to rice followed by raising groundnut as residual crop, to utilize the residual fertility was found the best nitrogen management package for rice-groundnut cropping system, not only in terms of higher productivity and economic returns, but also for sustaining the soil fertility status at a fairly high level.