Direct, residual and cumulative effects of organic manures and biofertilizers on yields, NPK uptake, grain quality and economics of wheat (Triticum aestivum L.) under organic farming of rice-wheat cropping system

Field experiments were conducted at the research farm of the Indian Agricultural Research Institute, New Delhi during rabi (winter) season of 2007-2008 and 2008-2009 on a sandy clay loam soil (typical Ustochrept, 51.46% sand, 23.02% silt and 25.52% clay)of low in organic C (0.57%), medium in available phosphorus (19.87 kg/ha), high in available potassium (247.12 kg/ha) and low in available nitrogen (163.2 kg/ha) and of pH 8. Results revealed that the cumulative effects of farmyard manure (FYM) and green manure (GM) were more effective than their direct and residual effects and GM was significantly superior to FYM for increasing the productivity, nutrient uptake, grain quality and gross and net income of wheat in the rice-wheat cropping system. Further,inoculation of biofertilizers (B) with GM was better than GM alone in its cumulative effect. The combination of GM + FYM was still better than GM or FYM alone in its direct and cumulative effects for increasing productivity and gross return, but net return was significantly reduced due to the higher cost of GM + FYM compared to FYM or GM alone. However, the residual effect of GM + FYM was similar to the cumulative effects of GM or FYM alone. The highest increase in productivity, grain quality and nutrient uptake was recorded with the application of GM + FYM + B. However, net return was significantly reduced due to the higher cost incurred in the combination of GM + FYM + B. It was concluded that the cumulative effect of GM + FYM + B for higher productivity and the cumulative effect of GM + B for higher net return were suitable for wheat in organic farming of the rice-wheat cropping system