The food-energy-water-carbon nexus of the rice-wheat production system in the western Indo-Gangetic Plain of India: An impact of irrigation system, conservational tillage and residue management

Abstract

The conventional rice-wheat system in the western Indo-Gangetic plain of India is energy and water intensive with high carbon footprint. The transition towards resource-efficient eco-friendly production technologies with lower footprint is required for inclusive ecological sustenance. A five-year (2016–17 to 2020–21) field experiment was conducted in RWS with hypothesis that pressurized irrigation systems [drip (DRIP) and mini-sprinkler (MSIS)] in conservation tillage [reduced (RT)/zero (ZT)] and crop residue management [incorporation (RI)/mulch (RM)] might result in higher resource use efficiency with lesser carbon footprint compared to conventional system. Experiment consisted five treatments namely (1) puddled transplanted rice followed by conventionally tilled wheat (PTR/CTW), (2) DRIP irrigated reduced till direct seeded rice (RTDSR) followed by zero-till wheat with 100 % rice residue mulching (ZTW + RM) (DRIP-RTDSR/ZTW + RM), (3) surface irrigated RTDSR followed by ZTW + RM (SIS-RTDSR/ZTW + RM), (4) MSIS irrigated RTDSR followed by ZTW + RM (MSIS-RTDSR/ZTW + RM), and (5) MSIS irrigated RTDSR with 1/3rd wheat residue incorporation followed by ZTW + RM (MSIS-RTDSR + RI/ZTW + RM). The pressurized irrigation system in RWS established under conservational tillage and residue management (DRIP-RTDSR/ZTW + RM and MSIS-DSR + RI/ZTW + RM) produced at par system productivity compared to PTR/CTW. Substantial nitrogen (79–114 ka ha−1) and irrigation water (536–680 mm) savings under pressurized irrigation systems resulted in 41–64 % higher partial factor productivity of nitrogen with 48–61 % lower water footprint. These systems had lower energy consumption attaining 15–21 % higher net energy, 44–61 % higher energy use efficiency, and 31–38 % lower specific energy. Efficient utilization of farm inputs caused lower greenhouse gas emission (39–44 %) and enhanced carbon sequestration (35–62 %) resulting 63–76 % lower carbon footprint over PTR/CTW. The information generated here might useful in developing policies for resource and climate–smart food production system aiming livelihood security and ecological sustainability in the region. Further, trials are needed for wider adaptability under different climate, soil and agronomic practices to develop site-specific climate smart practices.