*3.1. Energy Input*

Energy requirement was higher in rice than wheat in both years (Figures 1 and 2). In both crops, the second year had a higher energy requirement than the first year. Among all major operations, fertilization requires higher energy in rice, wheat and the rice–wheat cropping system. The share of fertilizer application in total energy consumption is 54–62%, 66–75% and 59–68% in rice, wheat and RWCS, respectively. The fertilization (54–62%), land preparation (17–22%) and irrigation (8–10%) are the three major consumers of energy in rice. The energy required for nursery, seed and sowing accounts for 10–11% in PTR, 5–6% SRI and 6% in ARS. In wheat, 66–75% of the total energy was accounted for by fertilization. The contribution of land preparation to the total energy consumption was 16–17% in CDW and SWI, while it was zero in ZTW (Figures 1 and 2). The seed requirement was the lowest in SWI and therefore accounts for only 3–4% of total energy. The CDW and ZTW require 11% and 16% energy for seed. In the case of system energy inputs, fertilization, land preparation and irrigation accounts for 59–68%, 9–19% and 6–10% of total energy, respectively. Among all operations, the energy required for nursery, seed requirement, land preparation and fertilization varies across CEMs. The renewable energy (seed and labour) consumption in rice varies from 1257.0 to 1879.7 MJ ha−1, while in wheat it varies from 1258.2 to 2516.6 MJ ha−<sup>1</sup> (Table 4). The highest renewable energy consumption was observed in ARS and ZTW, while the highest non-renewable energy consumption was recorded in PTR and CDW. In all CEMs of rice, indirect energy accounts for 61.8 to 69.9% of total energy inputs and in wheat its share is 75.9 to 90.7%. In rice, both direct and indirect energy consumption was highest in PTR. In case of wheat, direct energy consumption was highest in SWI, while indirect energy use was highest in ZTW (Table 5). The application of microbial consortia and Zn fertilization require 20 and 101 MJ ha−<sup>1</sup> energy, while the application of microbial consortia decreases energy requirements by 1964.5 MJ ha−<sup>1</sup> over RDN (Tables 4 and 5). Among CEMs, PTR had the highest energy requirement and it was higher by 1222–1229 and 2043–2391 MJ ha−1, respectively, than SRI and ARS. In wheat, ZTW reduces the energy requirement by 1655 and 684 MJ ha−<sup>1</sup> over CDW and SWI. On the system basis, ARS-ZTW was found superior in saving energy.

**Figure 1.** Effect of crop establishment methods on energy requirement for different inputs and operations in rice–wheat cropping system in 2013–2014.

**Figure 2.** *Cont.*

**Figure 2.** Effect of crop establishment methods (**a**) and nutrient management (**b**–**d**) on energy input requirement in rice–wheat cropping system. (T1: Control, T2: RDN, T3: RDN + Zn, T4: 75% RDN, T5: 75% RDN + Zn, T6: 75% RDN + MC1, T7: 75% RDN + MC1 + Zn, T8: 75% RDN + MC2 and T9: 75% RDN + MC2 + Zn). RDN Recommended dose of nutrients 120 kg N ha−<sup>1</sup> and 25.8 kg P ha−1; Zn: Soil applied with 5 kg Zn ha−<sup>1</sup> through zinc sulphate heptahydrate; MC1: (*Anabaena* sp. (CR1) + *Providencia* sp. (PR3) consortia; MC2: *Anabaena-Pseudomonas* biofilmed formulations.
