Energy input-output analysis under different farm sizes of forage maize cultivation in the Varamin region

Energy analysis in agriculture plays a significant role in developing the human perspective towards agricultural ecosystems, which enhances the quality of decision-making and planning in agricultural management and development. In this study, according to data obtained from the agricultural centers of the Varamin region, the different levels of forage maize cultivation were classified into three levels, less than one hectare (A1), between one to three hectares (A2), and more than three hectares (A3). By calculating the amount of input and output energy, energy evaluation indices, such as energy use efficiency, energy productivity, and net energy, were determined and compared at the different levels of utilization. According to the results, an increase in the cultivation levels, the human labor, machinery, diesel fuel, oil and nitrogen fertilizer (N) energies decreased, but the water for irrigation, phosphate (P2o5) fertilizer, potassium (K2O) fertilizer, pesticides, herbicides, and seed energies increased. On the other hand, the maximum amount of energy consumed at each level was calculated for nitrogen fertilizer inputs and diesel fuel, respectively, and the lowest ones were calculated for pesticides and potassium fertilizer, respectively. According to the results, the energy use efficiency in the different levels of utilization for A1, A2, and A3 levels was 11.02, 21.97, and 22.94, and the energy productivity for these levels was 1.37, 6.87, and 11.47 kg MJ-1, respectively. Finally, net energy ​​was calculated as 349175.43, 458157.76, and 478208.72 MJ ha-1, respectively.