Integrated nutrient management in soybean (Glycine max)—wheat (Triticum aestivum) cropping system

A field experiment was carried out during 2001–03 at Indian Agricultural Research Institute, New Delhi to study the impact of nutrient management practices on the growth, yield and economics of soybean (Glycine max)-wheat (Triticum aestivum) cropping system. The treatments consisted of combinations of 4 nutrient sources in main plots and 3 nutrient levels in subplots in soybean in rainy season. A general crop of wheat was grown during the following winter season to study the residual effect of treatments imposed on the previous soybean. The results indicated that application of 5 t/ha each of crop residues (CR) and farmyard manure (FYM) along with 5 kg zinc/ha among the nutrient sources and 100% recommended dose of fertilizer (RDF) among the nutrient levels recorded significantly higher growth and yield parameters and yield (1.62 t/ha) of soybean. The succeeding crop of wheat too showed a similar trend. The net returns were higher with 5 t/ha of FYM in soybean (Rs 8,154) and 5 t/ha each of CR and FYM alongwith 5 kg Zn/ha in succeeding wheat (Rs 12,577), as well as in soybean-wheat cropping system (Rs 20,334). The benefit:cost (B:C) ratio was higher with 100% RDF among nutrient levels (0.89) and with 5 t/ha CR (0.81) among the nutrient sources in soybean, whereas the 100% RDF among nutrient levels (0.73) and FYM @ 5 t/ha + CR @ 5 t/ha + 5 kg Zn/ha among sources given to soybean recorded higher B:C ratio (0.72) in wheat. The organic carbon and the available N, P, K and Zn were higher with 5 t/ha each of CR and FYM along with 5 kg zinc/ha among the nutrient sources, and 100% RDF among nutrient levels after the completion of 3 years of experimentation. It was concluded that combined application of 5 t/ha each of CR and FYM along with 5 kg/ha zinc is necessary for getting higher yield and net returns from soybean-wheat cropping system.