An Asian Journal of Soil Science

Manjunatha Hebbara ¹, B. G. Masthanareddy ², S. G. Patil ³, V. C. Patil ³

Affiliations
1 Department of Soil Science and Agricultural Chemistry, University of Agricultural Sciences, Dharwad (Karnataka), IN
2 Agricultural Research Station, Gangavati (Karnataka), IN
3 College of Agriculture, Bheemarayanagudi, Raichur (Karnataka), IN

Abstract

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.

Keywords

Transplanted Rice, Phosphorus, Potassium, Leaching Losses, Partial Balance.

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Manjunatha Hebbara ¹, B. G. Masthanareddy ², S. G. Patil ³, V. C. Patil ⁴

Affiliations
1 Department of Soil Science, Agriculture College, University of Agricultural Sciences, Dharwad (Karnataka), IN
2 Agricultural Research Station, Gangavathi, Koppal (Karnataka), IN
3 College of Agriculture, Bheemarayanagudi, Raichur (Karnataka), IN
4 College of Agriculture, University of Agricultural Sciences, Raichur (Karnataka), IN

Abstract

The effect of levels, splits and timings of NPK application on losses, uptake and use efficiency of P and K in transplanted rice (Oryza sativa L) was studied at Agricultural Research Station, Gangavathi, Karnataka, during kharif 2000 and summer 2001. A higher level of NPK application (L₂) was beneficial which increased both P and K uptake resulting in higher yields. Application of split doses of either N or NPK did not influence P and K uptake and grain yield. Though the yields were higher with L₂, their agronomic efficiency decreased over L1. The agronomic efficiency of P and K were unaffected by N / NPK splits with BPT-5204 (kharif) but NPK splits significantly increased the AE of both P and K over only N splits with IR-64 (rabi/ summer). Though the recovery of P was not influenced by its level, its extended application increased P recovery. However, in case of K, both increased levels and extended levels of K increased K recovery.

Keywords

Transplanted Rice, Phosphorus, Potassium, Uptake, Recovery Efficiency, Agronomic Efficiency.

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