Productivity, Nutrient Uptake and Profitability of Sweet Sorghum -Mustard Cropping System under Different Levels of Nitrogen

A field experiment was conducted during summer and winter seasons of 2009-10 and 2010-11 at Research Farm of Division of Agronomy, Indian Agricultural Research Institute, New Delhi to study the effects of nitrogen levels applied to sweet sorghum genotypes on productivity, nutrient uptake and profitability of sweet sorghum-mustard cropping system. Pooled analysis of data indicated that there was significant increase in green biomass, stalk, juice, brix (%), fermentable sugar and estimated ethanol yield due to application of nitrogen up to 100 kg N ha-1 over control. The highest grain yield (2.7 t ha-1) and fodder yield (15.6 t ha-1) were recorded with application of 150 kg N ha-1. Pooled analysis of data showed that hybrid ‘CSH 22 SS’ recorded the highest stalks (85.6 t ha -1 ), juice (30 t ha -1 ) , fermentable sugar (4.6 t ha -1 ) and estimated ethanol yield ( 2.6 kl ha -1 ). On an average grain yield (2.5 t ha -1 ) of hybrid ‘CSH 22 SS’ was 31.5% and 45.8% higher than ‘RSSV 9’ and ‘SSV 84’, respectively. Application of 150 kg N ha -1 to preceding sweet sorghum produced the highest values of plant height, number of branches plant-1, number of siliqua plant-1, number of seeds siliqua -1 , siliqua length, seed yield, biological yield and oil yield. Oil percent in mustard declined as nitrogen dose applied to preceding sweet sorghum increased. Residual effect of sweet sorghum genotypes on performance of succeeding mustard was not significant. Productivity, nutrient uptake and economics of sweet sorghum-mustard cropping system significantly increased due to application of nitrogen up to 150 kg ha -1 . The highest sorghum equivalent yield (6.2 t ha -1 ), net returns ( 66300= US $ 1326) and net benefit cost ratio (2.8) were recorded when 150 kg N ha-1 was applied. Among genotypes, including of CSH 22 SS hybrid significantly enhanced productivity, nutrient uptake and economics of system.