Response of Transplanted Rice to Levels, Splits and Timing of NPK Application:Effect on Losses and Partial Balance of P and K

The effect of levels, splits and timings of NPK application on losses and partial balance of P and K in transplanted rice (Oryza sativa L) was studied at Agricultural Research Station, Gangavathi, Karnataka, during kharif 2000 and summer 2001. Leaching losses of both P and K were significantly higher under 250:55:104 kg NPK ha^-1 compared to 150:33:63 kg NPK ha^-1 and under only N splits compared to NPK splits. Leaching losses of both P and K were significantly higher during early cropping period, especially from planting to active tillering stage, irrespective of season. Application of fertilizers even at RDF level resulted in significant build up of soil P. Partial net K balance was negative under both the levels of fertilization and seasons. Application of 250:55:104 kg NPK ha^-1 through NPK splits up to beginning of grain filling stage recorded significantly higher grain yield and lower P and K leaching losses during both the seasons.