Production potential and economics of different rainfed rice (Oryza sativa)-based utera cropping systems and its effect on fertility build up of soil

A field experiment was carried out during rainy (kharif) and winter (rabq seasons of 2001-2002 and 2002- 2003 at farmer's field of Burdwan, West Bengal, in Entisol soil, having pH 6.8, total N 0.070 %, available P 7.83 kg and available K 191.7 kglha, to evaluate the physical and economic performance of different utera crops grown on residual moisture after rice (Oryza sativa L.) under rainfed condition and its effect on fertility status of soil. Lathyrus (Lathyrus sativus L.) and linseed (Linum usitatissimum L.) proved to be promising utera crops. The highest yield (1,063 and 1 , I20 kglha) was obtained in both the years with Lathyrus as utera crop which was fol- lowed by that (607 and 670 kglha) when linseed was taken as utera crop. Similar trend was also observed for dry-matter accumulation at harvest of the utera crops. In terms of Lathyrus-equivalent yield, linseed exceeded Lathyrus. The highest Lathyrus-equivalent yield (1,214 and 1,340 kglha, respectively, in both years) was ob- tained with linseed as utera crop which was followed by that (1,063 and 1,120 kglha) when Lathyrus was taken as utera crop. The highest rice-equivalent yield (6,340 and 6,887 kglhalyear) was obtained in rice-linseed utera cropping system. Maximum soil moisture content at flowering stages of utera crops was obtained when Lathyrus was taken as utera crop. The highest nutrient uptake of NPK was recorded in rice-Lathyrus utera cropping sys- tem. In relation to fertility build up of soil, nutrient status in terms of total nitrogen was found to be significantly in- creased in rice-Lathyrus utera cropping system. Highest benefit : cost ratio was obtained in rice-linseed utera cropping system, followed by rice-Lathyrus utera cropping system.