Conservation tillage and planting practices in rice (Oryza sativa)-wheat (Triticum aestivum) cropping system for sustainable agriculture

A field experiment was conducted during the 6 consecutive rice (Oryza sativa L.)-wheat [Triticum aestivum (L.) emend. Fiori & Paol] crop cycles, starting from rainy (kharif) season 2004 to winter (rabi) season 2009–10 at the Research Farm, All India Coordinated Research Project on Integrated Farming System (ICAR), SKUAST-Jammu, Jammu and Kashmir, in a clay loam soil, with pH 8.1, soil organic carbon 0.55% and available N, P and K of 247.7, 22.0 and 103.3 kg/ha, respectively, to evaluate four rice (Oryza sativa)-establishment methods, viz. direct dry seeding, direct seeding of sprouted rice by drum seeder, manual transplanting and transplanting by hand transplanter and 4 wheat establishment methods in succeeding wheat crop, viz. bed planting by bed planter, conventional sowing by seed drill, strip till drilling by strip till drill and zero-till drilling by zero till drill for sustainability, productivity, profitability and energetics of rice-wheat system under sub-tropical irrigated conditions. The experiment was laidout in stripplot design with 3 replications. Keeping 4 rice and 4 wheat establishment methods in the strip resulted significantly higher overall yield attributes and average grain yield of rice (4.80 t/ha) under manual transplanting, whereas lower yield of 3.81 t/ha was obtained under direct dry seeding rice. Succeeding wheat crop sown with bed planter showed significantly higher number of tillers, grain/panicles and grain yield of 3.72 t/ha over other methods but at par with conventionally sown (3.63 t/ha). System productivity (8.44 t/ha) and sustainable yield index (0.75) of rice under conventional practices and wheat (0.79) under conventional sowing were the highest. Net return and benefit: cost ratio of the system was higher in the manual transplanting of rice (47.85 × 10³/ha and 1.81) and bed planting of wheat (46.40 × 10³/ha and 1.73). Manual transplanting reduced weed biomass by 26.7, 36.4 and 56.6% over hand transplanter drum seeding, and direct sowing of rice respectively. Among wheat establishment methods lower weed biomass (6.90 g/m²) was noticed under bed planting which was at par with conventional sowing of wheat (7.09 g/m²). Organic carbon content was slightly (up to 5%) build up in all the tillage and planting methods over initial level, but available N, P, K varied considerably from the initial status. Soil-bulk density was improved under manual transplanting (1.19 g/cm³) of rice and bed planting of wheat treatment (1.19 g/cm³). In fuel consumption, 18.6% and 44.1% savings were achieved with direct seeding in rice and zero till drilling in wheat establishment methods over conventional methods. In term of system energy-use efficiency and energy productivity was higher under manual transplanting of rice (10.79% and 0.19 kg/MJ) and bed planting for wheat (10.81% and 0.18 kg/MJ), whereas higher water productivity was noticed in paddy established through manual transplanting method (0.49 kg grain/m³) and wheat established through strip till drill (0.45 kg grain/m³).