Effect of liming, planting time and tillage on system productivity, profitability and resource-use efficiency of rice (Oryza sativa)-based cropping systems under rainfed valley land condition of North East India

A field experiment was conducted during 2010–12 at Imphal, Manipur, to study the effect of liming, planting time and tillage on system productivity, profitability and resource-use efficiency of rice (Oryza sativa L.)-rapeseed [Brassica campestris (L.) var. toria] and rice (Oryza sativa L.)-lathyrus or khasari (Lathyrus sativus L.) cropping systems. The treatments consisted of 2 factors, i.e. liming (liming and no liming) and planting time (early and normal) which were given to rice crop during rainy (kharif) season in the main plots. During the winter (rabi) season after rice, 2 tillage practices (no tillage and conventional tillage) were given in sub plots and again 2 rabi crops (rapeseed and lathyrus) in sub-subplots. The experiment was laid out in split split plot design with 3 replications. Application of lime @ 500 kg CaCO₃/ha before planting rice recorded higher system productivity in terms of riceequivalent yield (REY) of 6.30 t/ha, nitrogen-use efficiency (NUE) and water-use efficiency (WUE) of the system; however, it failed to increase benefit: cost ratio. Advancing planting time of rice 15 days ahead of normal planting enhanced growth and yield of rabi crops, resulting increase in REY (6.57 t/ha), land use efficiency (LUE), production efficiency and partial factor productivity (PFP) of the system by 16.70, 2.90, 13.05 and 16.1% respectively. No tillage enhanced PFP and NUE of the system, while conventional tillage increased energy consumption by 12.4%. Regarding cropping system, rice-rapeseed gave higher net return, benefit: cost ratio and production efficiency over rice-lathyrus system. However, rice-lathyrus system increased NUE, WUE and energy productivity. Rice-rapeseed system showed higher productivity and profitability under conventional tillage and normal planting, but rice-lathyrus gave better performance under early planting with no tillage.