Productivity, nitrogen-use efficiency and economics of sweet sorghum (Sorghum bicolour) genotypes as influenced by different levels of nitrogen Miri Khaled, Rana D.S.1, Principal Scientist, Rana K.S.1, Principal Scientist, Kumar Ashok2, Principal Scientist Indian Agricultural Research Institute, New Delhi, 110 012 1Division of Agronomy 2DMR, New Delhi Corresponding authors: *Email: kh_miri2003@yahoo.com
**Email: dsrana5554@yahoo.com
Based on a part of Ph.D. thesis of first author submitted to IARI, New Delhi, during 2011 Online published on 10 April, 2012. Abstract A field experiment was conducted at New Delhi, during rainy seasons of 2009 and 2010 to evaluate 3 sweet sorghum {Sorghum bicolour (L.) Monech} genotypes (‘RSSV 9’, ‘SSV 84’ and hybrid ‘CSH 22 SS’) under four nitrogen levels (0, 50, 100 and 150 kg N/ha) for productivity of ethanol, grain and fodder, nitrogen-use efficiency and economics of production. Results pooled over two years indicated that stalk yield (75.3 t/ha) and fodder yield (16.0 t/ha) recorded significant increase only up to 100 kg N/ha, while fermentable sugar (4.34 t/ha), estimated ethanol (2.46 KL/ha) and grain yields (2.6 t/ha) responded up to 150 kg N/ha. Hybrid ‘CSH 22 SS’ recorded 28, 40, 34, 34, 33 and 26% higher stalks (85.6 t/ha), juice (30 KL/ha), fermentable sugar (4.6 t/ha), estimated ethanol (2.6 KL/ha), grain (2.4 t/ha and fodder (16.8 t/ha) yields than genotype ‘RSSV 9’ and 57, 110, 112, 112, 41 and 46% than genotype ‘SSV 84’. Sorghum grain equivalent (11.1 t/ha) based on ethanol, grain and fodder yields recorded with 150 kg N/ha was significantly higher over 100 kg N/ha. Hybrid ‘CSH 22 SS’ recorded significantly higher sorghum grain equivalent yield (11.35 t/ha), when compared to ‘SSV 84’ (6.15 t/ha) and ‘RSSV 9’ (8.53 t/ha). Nitrogen-use efficiencies like partial factor productivity, agronomic nitrogen-use efficiency and crop recovery efficiency decreased with increasing dose of nitrogen. ‘CSH 22 SS’ had the highest agronomic nitrogen-use efficiency (14.5 kg grain/kg N applied) and partial factor productivity (30.7 kg/kg N applied) followed by ‘RSSV 9’. Maximum gross returns ( 101,410), net returns ( 55,670) and net B:C ratio (1.17) were recorded with application of 150 kg N/ha. ‘CSH 22 SS’ produced the highest net returns ( 55,900), which was (105 and 39% higher over ‘SSV 84’ and ‘RSSV 9’, respectively. Application of 150 kg N with ‘CSH 22 SS’ produced the highest values of juice yield (40KL/ha), estimated ethanol yield (3.47 KL/ha) and grain yield (3.3 t/ha). Top Keywords Economics, Ethanol yield, Genotypes, Grain yield, Nitrogen-use efficiency, Sweet sorghum. Top |