Effect of crop residue incorporation on the relative efficiency of diammonium phosphate and mussoorie rock phosphate in rice (Oryza sativa)- wheat (Triticum aestivum) cropping system

Abstract

The field experiments were carried out at New Delhi during 1993-94 to 1995-96 to study the effect of incorporation of wheat (Triticum aestivum L, emend, Fiori and Paol.) and rice (Orvza sativa L.) residue on the relative efficiency of diammonium phosphate and mussoorie rock phosphate in rice-wheat cropping system, Incorporation of wheat residue before rice transplanting resulted in an increase in the efficicncy of mussoorie rock phosphate in rice which responded well to applied phosphorus, With residue incorporation mussoorie rock phosphate increased grain yield and P uptake of rice and available phosphorus content of soil similar to diammonium phosphate, Without residue incorporation mussoorie rock phosphate had no significant effect on grain yield and P uptake to rice crop and on available phosphorus content of soil. Incorporation of rice residue before wheat sowing had no such significant effect on grain and straw yields and phosphorus uptake of wheat but had a significant resudual effect on grain yield and phosphorus uptake succeeding rice, Incorporation of rice residue also increased the efficiency of mllssoorie rock phosphate as indicated by available phosphorus content of soii. The study indicate that incorporation of crop residue not only increase the grain yield and phosphorus-uptake of rice but also resulted in an increase in the efficiency of mussoorie rock phosphate and available phosphorus built-up.