Fig. 3.

Scatter plot of treatments on PCA coordinates and their association with energy parameters (a). Loading value (correlation) of different variables for PC1 and PC2 (b). Heat map and cluster presentation of treatments based on the energy parameters (c). LP energy input for land preparation, RES crop residue energy input, S/T energy input for sowing/transplanting, FERT energy input for fertilizers application, IRR energy input for irrigation management, INT energy input for intercultural operation, HERB energy input for herbicide and its application, PP energy input for plant protection, HAR energy input for harvesting, IE input energy, OE output energy, RGEY system rice equivalent yield, ER energy ratio, EP energy productivity, NE net energy, RW rice–wheat, RM rice–maize, T1 CTTPR-CT, T2 NPTPR-ZT, T3 ZTTPR-ZT, T4 ZTDSR-ZT, R− residue removal, R+ residue retention (for heat map, R stands for residue retention)