Crop productivity, returns and soil sustainability under rice (Oryza sativa)-wheat (Triticum aestivum) cropping system

A field experiment was conducted during 1997-98 to 1999-2000 at Regional Research Station, Uchani, Karnal, Haryana, to study the effect of organic sources and recommended chemical fertilizers and higher doses of nutrients applied through recommended inorganic sources along with organic sources on rice (Oryza sativa L.) and succeeding wheat (Triticum aestivum L. emend. Fiori & Paol.). Higher productivity of rice-wheat cropping system with application of 150% recommended fertilizers + green-manuring in rainy season (khario and 150% recommended fertilizers + 10 tonnes/ha FYM to winter (rabi) crop gave the higher rice-equivalent productivity of 14,141 kg/ha and net returns of Rs 35,160/ha compared with 10,923 kg/ha total rice-equivalent productivity and net returns of Rs 25,041/ha recorded in 100% recommended fertilizers to both kharif and rabi crops. Negative values of nutrients balance were recorded in treatments where only 100%, 125% and 150% chemical fertilizers were applied. Nutrient's balance of (+) 314.0, 279.8 and 268.6 kg/ha was recorded with 100%, 125% and 150% recommended fertilizers + green-manuring in kharif and 10 tonnes/ha FYM in rabi crop respectively. [100% NPK levels : 120, 60 and 0, and 120, 60 and 60, N, P2O5 and K2O, kg/ha, respectively, to rice and wheat crops in the sequence, year after year.]