Productivity-profitability-energy-carbon footprint nexus of wheat in relation to its establishment vis-à-vis in-situ rice residue management with a novel Surface Seeding-cum-Mulching technique

Rice residue management remains one of the critical challenges for rice-growing regions of North-Western India, on the other hand, it's one of the big opportunities to suppress weeds by laying these residues horizontally in-situ as mulch for weed suppression. An experiment was conducted to evaluate the effects of weed control and wheat seeding techniques in rice residue management during 2019–2020 and 2020–2021. Treatments included two weed control methods (herbicide and without herbicide) in main plots and three seeding techniques (Surface Seeding-cum-Mulching, Happy and Super Seeder) arranged in subplots with three replications. Post-emergence herbicide application resulted in higher grain yield (53.3 q/ha), straw yield (72.2 q/ha), energy ratio (10.7), energy productivity (0.33) and carbon sustainability index (6.68) over without herbicide application. Surface Seeding-cum-Mulching recorded significantly lower weed density, higher number of ears/m2, grains/ear, grain and straw yield, gross returns, net returns and benefit cost ratio followed by Happy and Super Seeder. Surface Seeding-cum-Mulching demonstrated 45 and 32.4 % lower diesel fuel energy input and 48.2 and 35.4 % lower agri-machinery energy input compared to Super and Happy Seeder, respectively. Surface Seeding-cum-Mulching also recorded significantly higher total energy output, energy ratio, energy productivity and net energy gain than the other methods. The highest carbon footprints were recorded under the Super Seeder (0.16 kg CE/kg wheat yield), followed by the Happy Seeder (0.14 kg CE/kg) and the Surface Seeding-cum-Mulching technique (0.13 kg CE/kg).