Evaluation of Energy Flow in Irrigated Wheat Agro Ecosystems

Evaluation of energy flow in agro ecosystems is considered to be a valuable technique for evaluation the sustainability level of these ecosystems. Hence, a study was conducted in 2009-10 growing season to evaluate energy input, output and energy balance indices of irrigated wheat production in Shahre -e- Rey, Iran. The total energy input and output for wheat production was found to be 47377.6 and 124990 MJ ha-1, respectively. The largest share of energy inputs was related to chemical nitrogen fertilizer followed by diesel fuel and machinery which were responsible for 31.1, 19.9 and 12.15% of the total energy input, respectively. Net energy, energy use efficiency and energy productivity of the wheat farms were calculated as 77611.6 MJ ha, 2.63 and 0.11 kg MJ-1, respectively. The contribution of indirect energy was 62.1% and share of nonrenewable energy was 72.2% of the total energy input. Although the net energy produced in the wheat farms of the targeted area was considerably higher than those reported for the other areas of the country, but energy were not consumed quite efficient. Furthermore, the share of non renewable energy for wheat production was relatively high and efforts should be made to substitute renewable sources for some part of the non renewable sources.