Yield gap analysis in kharif sorghum hybrid CSH-16 across 12 districts of north interior Karnataka, India : Yield gap in kharif sorghum hybrid

Abstract

In North Interior Karnataka (NIK) sorghum is grown during both kharif and rabi seasons and CSH-16 is a nationally released hybrid for kharif season. The yield gap analysis is very essential to quantify the difference between potential yield (i.e., no moisture stress) and actual yield of a given crop cultivar under rainfed conditions so that agronomic adaptations are devised to fill the gap. This plays very important role under rainfed conditions because the yield is often limited by water stress followed by N stress. For this, calibrated and validated DSSAT-CERES was used to run simulations from 1988 to 2018 (31 years) for the kharif sorghum hybrid CSH-16 under potential and rainfed conditions on two predominant soils (black clay and red loamy) across 12 districts of NIK. The results showed that average grain yield for NIK in rainfed condition was 2734 kg/ha, with 2272 kg/ha on black clay soil and 3195 kg/ha on red loamy soil. When crop was grown under potential conditions the yield level improved, on average, by 13.0 % to 3079 kg/ha, with 2630 kg/ha on black clay soil and 3528 kg/ha on red loamy soil, indicating that there is a scope to improve grain yield by providing irrigation at critical stages. Across 12 districts of NIK under current climate (1988-2018) on black clay soils the highest yield gap (76 %) was simulated for Koppal district and the lowest yield gap (0.8 %) simulated for Bidar district. Similarly, on red loamy soils the highest yield gap (25 %) was simulated for Vijayapura district and the lowest yield gap (0.1 %) simulated for Bidar district indicating higher yield gap on black clay soil than on red loamy soil.