Moisture conservation and site specific nutrient management for enhancing productivity in rainfed finger millet+pigeonpea intercropping system in Alfisols of south India

The response of finger millet+pigeonpea intercropping system for a targeted yield of 4.0 t ha ⁻¹ (finger millet equivalent yield) under site specific nutrient management, was field investigated from 2008 to 2011 at AICRPDA, Bangalore, India. The results of 4 years data indicated that the site specific nutrient management (155: 45: 203 kg ha ⁻¹ N, P₂ O₅ and K₂ O) along with conservation furrow in between the rows of pigeonpea recorded a higher mean finger millet grain equivalent yield ( 3,794 kg ha⁻¹) with higher net returns ( 29,707 ha⁻¹) and B:C ratio (2.73) whereas, application of recommended NPK (50: 40: 25 kg ha⁻¹) recorded a finger millet grain equivalent yield of 2,367 kg ha ⁻¹ with net returns ( 15,067 ha⁻¹) and B:C ratio (2.04). The soil nutrient status studies after the harvest of the crop revealed that the site specific nutrient management treatment recorded significantly higher organic carbon, available N, P₂ O₅ and K₂ O and increased the uptake of 189 N kg ha⁻¹, 89.2 kg P ha⁻¹ and 133 kg K ha⁻¹ with an uptake response of 143% N, 86% P and 192% K compared to other treatments. Significantly higher values of exchangeable Ca and Mg were recorded with lime application. The site specific nutrient management approach has proved greater RWUE in grain production (5.44 to 9.80 kg ha mm) and one mm of rainfall has yielded net returns between 39 to 82 i.e., RWUE in economic terms. The conservation furrow between two rows of pigeonpea conserved rainwater in-situ the moisture for longer period which in turn has facilitated better utilization of applied nutrients for better plant growth which has contributed for higher yields