*2.5. Energy Calculation*

For calculation of gross energy, grain and straw yield was measured and their cited energy equivalents [16,18] were considered. The energy equivalents mentioned in [16–18] were used to calculate the energy input (Table 3). The energy input consists of both direct (human labour, diesel and electricity) and indirect (seed, fertilizers and machinery) energy in rice and wheat. The net energy output is calculated by subtracting energy input from gross energy output. The energy input is also expressed as energy tonne−<sup>1</sup> of economic yield produced.
