Yield and nutrient budgeting as influenced by organic sources of nutrients and weed management in rice-potato-frenchbean cropping system

A field experiment was conducted during 2015–16 and 2016–17 under different organic sources of nutrients and weed management in rice (Oryza sativa L.) - potato (Solanum tuberosum L.)-frenchbean (Phaseolus vulgaris) cropping system with six sources of nutrients as main-plot treatments and four weed management practices as sub-plot treatments. Among the organic sources of nutrients, application of 100% organics (100% recommended N through different organic sources each equivalent to 1/3 of recommended N i.e. FYM+ vermicompost + non-edible oil cake) + VAM recorded significantly maximum individual crop yield and rice equivalent yield (REY). The highest apparent balance of nitrogen and phosphorus was recorded with the application of 100% recommended NPK + secondary and micronutrients based on soil test through inorganic fertilizer and 50% recommended N through vermicompost + biofertilizers for N + rock phosphate to substitute the P requirement + PSB. Whereas, the balance of available potassium in soil was negative with the application of different sources of nutrients. Application of mustard seed meal @ 5 t/ha registered significantly higher yield of crops, REY and apparent balance of nitrogen. However, the balance of available phosphorous and potassium in soil was recorded hig hest with the application of rice bran @ 4 t/ha.