OPTIMIZATION AND VALIDATION OF TARGETED YIELD EQUATION-BASED FERTILIZER DOSES UNDER INM FOR WHEAT IN TARAI REGION OF UTTARAKHAND, INDIA.

Response of wheat to twenty four selected treatment combinations of four levels of N, P, K and three levels of FYM with simultaneous variation in initially available nutrients was studied under soil-test-crop-response calibration in Aquic Hapludoll during 2005-07. To produce 100 kg of grain, 2.72, 0.49, 2.67 kg of N, P, K were required. Per cent contribution of nutrients each through soil, chemical fertilizer and FYM were also computed. Yield and soil analysis data were utilized to formulate prescription equations for varying yield targets. Significant R2 (0.914) was observed between yield and soil test values and fertilizer nutrients. N correlated most with grain yield and quality parameters. Verification trial was also conducted in next season, revealed the highest response and benefiticost ratio were found to be with yield target 4.5 t/ha + FYM @ 101/ha, with a targeted yield variation of -2.78 to +0.9%. [ABSTRACT FROM AUTHOR]