Abstract

Field experiments were conducted during 2011–14 at Tamil Nadu Agricultural University, Coimbatore to identify the appropriate bio-intensive complementary cropping systems for irrigated uplands of Tamil Nadu. The experiments were laid out in randomized block design with three replications. Among the different cropping systems tested, onioncotton-maize cropping system produced significantly higher cotton equivalent yield of 5407 kg/ha and it was comparable with greengram-cotton+sunnhemp-sunflower (5116 kg/ha) and fodder sorghum-cotton+onion+sunnhemp-lablab cropping (5034 kg/ha) systems. This system also recorded higher production efficiency (16.38 kg/ha/day) and economic efficiency (561 Rs./ha/day), which indicates the need for integration of vegetable crops due to higher per day productivity over the other crops. The higher B: C ratio (3.18) and sustainability yield index (SYI) (0.98) were registered in onion-cotton-maize cropping system. The higher water use efficiency (WUE) was noticed in onion-cotton-maize cropping system (3.28 kg/ha/mm). Green manuring of sunnhemp (Crotalaria juncea) improved organic carbon, available N, P and K level of the respective cropping sequence over the others.