TILLAGE AND RESIDUE MANAGEMENT FOR IMPROVING PRODUCTIVITY AND RESOURCE-USE EFFICIENCY IN SOYBEAN (GLYCINE MAX)—WHEAT (TRITICUM AESTIVUM) CROPPING SYSTEM

Abstract

SUMMARYContinuous rice–wheat (RW) cropping in an area of 13.5 million ha with intensive tillage has resulted in over exploitation of resources, decline of the factor productivity, loss of soil fertility and biodiversity and decline of resource use efficiency in the Indo-Gangetic plains (IGPs) of South Asia. This has led to unsustainability of agriculture in the region. Replacement of a cereal-cereal system with a legume–cereal system may prove beneficial for long-term sustainability of the system. A field experiment was conducted with soybean–wheat (SW) rotation in the IGP of India during 2009–10 and 2010–11 to assess the suitability of conservation tillage versus conventional tillage (CT) and crop-establishment techniques, namely bed (B) planting versus flat (F) planting. The study revealed that the zero tillage (ZT) for soybean during rainy and for wheat during winter season either in flat or in bed system performed equally good with CT. The maximum system productivity (7.06 t ha−1in 2009–10 and 8.48 t ha−1in 2010–11) was obtained with combined application of wheat + soybean residue. The maximum net returns of ₹46.98 and ₹65.08 thousands and B:C ratio of 2.35 and 3.08 were recorded in the SW system with zero tillage-flat (ZT─F) during 2009–10 and 2010–11, respectively. The minimum energy of 64.67 and 63.01 ×103MJ ha−1was utilized as input energy with zero tillage-bed (ZT─B) while the maximum energy use efficiency of 4.10 and 5.14 was obtained with ZT─F and ZT─B for the SW system during 2009–10 and 2010–11 respectively. The gross output energy was maximum with wheat + soybean residue (241.6 and 265.7 ×103MJ ha−1) contrary to this the net energy (194.4 and 213.4 ×103MJ ha−1) and energy use efficiency (9.03 and 10.96) was maximum with control (no residue) in the SW system. In wheat there was 37.85% improvement in irrigation water use efficiency (WUE) in raised bed planting than flat planting and 28.57% of irrigation water was saved. The study suggested that ZT either bed or flat planting to both the crops can successfully adopted along with application wheat + soybean residue together with full recommended dose of NPK fertilizers to the system for improving productivity, profitability, soil health and sustainability of SW system in the IGPs of South Asia.