Influence of Nutrient Supply Levels on Yield, Nutrient Uptake, Grain Quality and Economics of Corn (Zea mays L.) in Alfisols of Karnataka

A field experiment was conducted at Dryland Agriculture Project, Bangalore during kharif seasons of 2006 and 2007 to evaluate the influence of fertilizer levels on corn (Zea mays L.) yield, quality, nutrient uptake and economic returns. The treatments consist of corn genotypes NAH-2049 and NAC 6004. Fertilizer level treatment consists of N (0, 100, 150 and 200 kg/ha), P₂O₅ (0, 50, 75 and 100 kg/ha) and K₂O (0, 25, 50 and 75 kg/ha) along with or without elemental Sulphur (0 and 10 kg/ha) and ZnSO₄ (0 and 12.5 kg/ha) compared to site specific nutrient management (SSNM target 8 t/ha), soil test crop response (STCR target 8 t/ha) and state recommended dose of fertilizers (RDF).The results of the study indicated that hybrid NAH-2049 (5129 kg/ha) was out yielded over NAC-6004 (4811 kg/ha) in both the years. However, nutritional qualities were non-significant except grain oil content between genotypes. Targeted yield based fertilizer application either by SSNM or STCR approach recorded significantly higher grain yield, oil and crude protein yield, starch and phenol content over state recommendation. Significant improvement in N, P, K, S and Zn uptake was recorded under SSNM and STCR approaches. SSNM approach fared well and gave higher net returns ( 28.94 x 10³/ha) and B: C ratio (2.06). Application of fertilizer based on target can enhance the yield, nutrient uptake and economic returns from the production of corn in Alfisols of Karnataka.