Maximizing system productivity and profitability through crop intensification and diversification with rice (Oryza sativa)-based cropping systems in acid soils of Assam

A field experiment was conducted for 6 consecutive years during 2008–09 to 2013–14, at Jorhat, Assam, to study the soil fertility, system productivity and profitability through crop intensification and diversification with rice (Oryza sativa L.)-based cropping system under irrigated medium land acid soil situation of Assam. From the pool analysis of data, it was observed that rice-equivalent yield, system productivity and nutrient-use productivity were found to be the highest in winter rice-cabbage [Brassica oleracea (L.) greengram [Vigna radiata (L.) Wilczek] (REY 17.72 t/ha) sequence, followed by winter rice-chilli (Capsicum annuum L.)-blackgram [Vigna mungo (L.) Hepper] sequence (REY 14.37 t/ha) among the 8 cropping sequences under study. There were improvements in post harvest physico-chemical properties of soil in different rice-based cropping systems. Significant variation with 34.0, 36.9 and 65.5% increase in available N, P₂O₅ and K₂O, respectively, were recorded in winter rice-radish (Raphanus sativus L.)-French bean-greengram sequences over initial status of soil. Total uptake of nutrients were also the highest of winter rice-radish-French bean-greengram sequence followed by winter rice-knolkhol [Brassica oleracea L. convar. acephala (L.) Alef. Var. gongylodes L.]-French bean-cowpea [Vigna unguiculata (L.) Walp.] (fodder) sequence. Economic analysis of the systems revealed that the highest gross returns (210.8 × 10³/ha), net returns (145.1 × 10³/ha) and benefit: cost ratio (2.21) were recorded in winter rice-cabbage-greengram sequence under irrigated medium land situation of Assam.