*3.2. Energy Production*

The PTR and SRI were found statistically superior to ARS in gross energy production in both years (Table 6). The net energy production in SRI was significantly higher over both PTR and ARS, while between PTR and ARS, PTR was found superior to ARS. The net energy production in SRI was higher by 1000 to 1500 MJ ha−<sup>1</sup> over PTR and 4800 to 5100 MJ ha−<sup>1</sup> over ARS. The lower net energy production in ARS was mainly due to lower yield. The saving in energy per tonne of rough rice produced in ARS was 401–492 and 86–167 MJ t−<sup>1</sup> more than PTR and SRI. In the case of wheat, both gross and net energy production in ZTW were significantly higher than CDW and SWI. The increase in gross and net energy production in ZTW over CDW was 7500–8000 and 9200–9600 MJ ha−<sup>1</sup> and similarly for ZTW versus SWI was 8200–8600 and 8900–9300 MJ ha−1, respectively. The ZTW required the lowest amount of energy for production of a tonne of grain. The saving in energy per tonne of grain produced was 216–488 and 274–275 MJ ha−<sup>1</sup> over CDW and SWI, respectively. The system gross energy output was highest in ARS–ZTW but remained on par with all other CEMs in the first year. During the second year, gross energy production in ARS–ZTW was significantly higher than SRI–SWI and remained on par with PTR–CDW. In regard to net energy production, ARS–ZTW was found superior to both PTR–CDW and SRI–SWI and increased net energy production by 5900 and 4100 MJ ha−1. The energy required to produce a tonne of system yield varied between 2523 and 3039 MJ ha−<sup>1</sup> and all three systems differed significantly, with ARS–ZTW found superior over the rest.

*Sustainability* **2022**, *14*, 5986





**Table 5.** Partitioning of energy inputs in different forms of energy in selected crop establishment methods of wheat during first cycle of RWCS.


*Sustainability* **2022**, *14*, 5986



**Table 6.** Effect of crop establishment methods on energetic and protein yield of rice, wheat and rice–wheat cropping system.

Within a column, means followed by the same letter are not significantly different at the 0.05 level of probability by the Duncan's multiple range test.

The gross energy production in rice was highest in RDN + Zn applied in PTR and found significantly superior over same treatments applied in SRI and ARS in both years (Table 7). Application of 75% RDN + MC1 + Zn and 75% RDN + MC2 + Zn in PTR and SRI remained on par with RDN and found significantly superior over same treatment applied in ARS in first year, while in second year only 75% RDN + MC2 + Zn in SRI was found on par with RDN. The net energy production was highest in 75% RDN + MC2 + Zn in SRI and found superior over same treatment applied in ARS in both years. The net energy production in 75% RDN + MC2 was higher by 900–1000 and 7300–8600 MJ ha−<sup>1</sup> than RDN and 75% RDN (averaged over all CEMs). Application of MC1 increased net energy production by 6800–8300, 6900–8500 and 7100–8600 MJ ha−1, respectively, in PTR, SRI and ARS. Similarly, increase in net energy production by MC2 was 7100–8400, 7000–8600 and 7500–8800 MJ ha−1, respectively. The zinc fertilization significantly increased gross and net energy production in all CEMs and in all treatments. The increase in gross and net energy production due to Zn fertilization varied between 1600 and 7300 and 1400 and 7100 MJ ha−1, respectively. The lowest amount of energy for production of one tonne of grain was in control. Among CEMs, control in ARS had significantly lower energy per tonne of rice grain produced. Application of MC1 lower energy required per tonne of grain produced by 167–233 MJ tonne−<sup>1</sup> and MC2 by 183 to 234 MJ tonne−<sup>1</sup> over 75% RDN.


**Table 7.** Effect of nutrient management options on energetic and protein yield of rice in different crop establishment methods.

Within a column, means followed by the same letter are not significantly different at the 0.05 level of probability by the Duncan's multiple range test. "\*": Indicates significant different of treatments the 0.05 level of probability by the Duncan's multiple range test; RDN \*: Recommended dose of nutrients 120 kg N ha−<sup>1</sup> and 25.8 kg P ha−1; Zn \*\*: Soil applied 5 kg Zn ha−<sup>1</sup> through zinc sulphate heptahydrate; MC1: (*Anabaena* sp. (CR1) + *Providencia* sp. (PR3) consortia; MC2: *Anabaena-Pseudomonas* biofilmed formulations.

In wheat, the highest amount of gross energy production was recorded in RDN + Zn in ZTW and remained on par with 75% RDN + MC1 + Zn and 75% RDN + MC2 + Zn in ZTW (Table 8). These three treatments were found significantly superior over same treatment applied in CDW and SWI except RDN in CDW. The net energy production in second year was 100 to 3500 MJ ha−<sup>1</sup> higher than first year. The application of 75% RDN + MC2 + Zn had the highest net energy production. Application of MC1 and MC2 increases net energy production by 5500 to 6700 and 6800 to 7700 MJ ha−1. Similarly increase in net energy production due to Zn fertilization was 1200 to 7900 MJ ha−1. The energy per tonne of wheat grain produced varied between 786 and 2858 MJ tonne−<sup>1</sup> in the first year and 853 and 2956 MJ tonne−<sup>1</sup> in the second year. Application of microbial consortia significantly reduces energy required for production of one tonne of wheat grain, while Zn fertilization found statistically superior when applied with RDN in CDW during both the years and 75% RDN + MC1 in CDW and SWI in first year. The system gross and net energy production varied between 247.2 and 311.9 <sup>×</sup> <sup>10</sup><sup>3</sup> MJ ha−<sup>1</sup> and 233.6 and 288.3 <sup>×</sup> <sup>10</sup><sup>3</sup> MJ ha−<sup>1</sup> (Table 9). The highest gross and net energy production was found with RDN + Zn in ZTW and 75% RDN + MC2 + Zn in ZTW, respectively. The increase in system net returns due to microbial consortia and Zn fertilization was 12,900 to 16,100 and 4800 to 12,040 MJ ha−1, respectively.

**Table 8.** Effect of nutrient management options on energetic and protein yield of wheat in different crop establishment methods.



**Table 8.** *Cont.*

Within a column, means followed by the same letter are not significantly different at the 0.05 level of probability by the Duncan's multiple range test. "\*": Indicates significant different of treatments the 0.05 level of probability by the Duncan's multiple range test; 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.

**Table 9.** Effect of nutrient management options on energetic and protein yield of rice–wheat cropping system in different crop establishment methods.



**Table 9.** *Cont.*

Within a column, means followed by the same letter are not significantly different at the 0.05 level of probability by the Duncan's multiple range test. "\*": Indicates significant different of treatments the 0.05 level of probability by the Duncan's multiple range test; 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.
