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

Experiments were conducted to test the superiority of treatment combinations of nitrogen (N; 0, 50, 100, 150, 200kgha(-1)), phosphorus (0, 30, 60, 90kgha(-1)) and potassium (0, 30, 60kgha(-1)) for finger millet during 2005-2007. Application of 200-90-60kgha(-1) gave maximum yield of 1666, 1426 and 1640kgha(-1) in 3years, 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 1200kgha(-1) were derived at soil nitrogen, phosphorus and potassium of 75-400, 10-70 and 150-750kgha(-1). Fertilizer nitrogen, phosphorus and potassium ranged from 30-128, 3-19, 13-25kgha(-1) and 105-203, 4-32, 27-39kgha(-1) for attaining 800 and 1200kgha(-1) yield, respectively. The doses could be adopted for attaining sustainable yields under semiarid Alfisols.