Energy-use audit and data envelopment analysis based optimization of tillage and residue management in rice-wheat system of Indo-Gangetic plains

Implementing zero and minimum tillage practices, along with residue and nitrogen management, significantly boosts crop production, energy efficiency, and environmental sustainability. The study evaluated energy use in rice-wheat cultivation under various tillage regimes: zero tillage with residue retention (ZTR), conventional tillage with residue incorporation (CTR), minimum tillage with biochar incorporation (MTB), conventional tillage with biochar incorporation (CTB), and conventional tillage alone (CT). These were combined with nitrogen management using biochar-coated fertilizers at different doses. Using data envelopment analysis (DEA) with BCC and CCR models on 30 decision-making units, the results indicated that ZTR with 125 % of the recommended nitrogen produced highest grain yield energy (206939.3 MJ ha⁻¹), followed by MTB. The MTB regime was energy efficient, using 13.7–52.1 % less input energy than other tillage methods. Significant energy savings were observed in irrigation (521 ± 127 MJ ha⁻¹), fertilizers (173 ± 65 MJ ha⁻¹), fuel (172 ± 39 MJ ha⁻¹), and electricity (168 ± 44 MJ ha⁻¹). According to the DEA models, 70 % of the DMUs were inefficient in input energy use, while 30 % were efficient. By optimizing tillage, residue, and nitrogen management, up to 20,795 ± 5557 MJ ha⁻¹ (12.76 %) of input energy can be conserved in the rice-wheat system.