Yield, nutrient uptake and soil fertility balance as influenced by organic and inorganic nutrient sources in urdbean-wheat cropping system

Abstract

A field experiment was conducted at Department of Agronomy, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, to study the direct and residual effect of organic and inorganic sources of nutrients under urdbean-wheat cropping sequence. Growth parameters viz. plant population/m2, plant height, branches/plant and dry matter accumulation/plant at maturity varied significantly due to farmyard manure @ 5t/ha and/or phosphorus @ 40kg P2O5/ha than that of their respective control during both the years. Significantly higher grain yield and NPK uptake in urdbean were also obtained with farmyard manure and phosphorus application over control. Wheat yield (grain, straw and biological) and K uptake did not differ significantly due to residual effect of farmyard manure and phosphorus, whereas NPK uptake varied with residual farmyard manure and phosphorus applied to urdbean during both the years. Maximum grain, straw and biological yield and NPK uptake in wheat were recorded with 100% of recommended fertilizer level, being on par with 75% of recommended level, as compared to 50% of recommended level during both the years. The wheat grain yield with 75% of recommended NPK out yielded 3.14 and 4.08q/ha than 50% of recommended NPK during 2004-05 and 2005-06, respectively. After two crop cycle, the minimum depletion (positive balance ie. the lowest negative values for nitrogen and potassium) was observed at highest fertility level (5t FYM with 40 kg P2O5/ha to urdbean+100% NPK to wheat).