Modeling of Soil-Plant-Fertilizer Relationships for Optimizing Fertilizer Doses for Different Levels of Finger Millet Yield under Semi-Arid Alfisols

ABSTRACTExperiments were conducted to test the superiority of treatment combinations of nitrogen (N; 0, 50, 100, 150, 200 kg ha−1), phosphorus (0, 30, 60, 90 kg ha−1) and potassium (0, 30, 60 kg ha−1) for finger millet during 2005–2007. Application of 200-90-60 kg ha−1 gave maximum yield of 1666, 1426 and 1640 kg ha−1 in 3 years, respectively. The yield regression model through soil and fertilizer nutrients gave predictability of 0.98, 0.97 and 0.98, with sustainability yield index (SYI) of 50.4, 49.4 and 52.5 in 2005, 2006 and 2007, respectively. Optimum nitrogen, phosphorus and potassium (NPK) doses for attaining yields of 800 and 1200 kg ha−1 were derived at soil nitrogen, phosphorus and potassium of 75–400, 10–70 and 150–750 kg ha−1. Fertilizer nitrogen, phosphorus and potassium ranged from 30–128, 3–19, 13–25 kg ha−1 and 105–203, 4–32, 27–39 kg ha−1 for attaining 800 and 1200 kg ha−1 yield, respectively. The doses could be adopted for attaining sustainable yields under semiarid Alfisols.