Assessment of energy flow in irrigated and dry-land wheat farms under different climatic conditions in Kermanshah province

Energy management in agroecosystems helps to attain efficient and sustainable use of energy. The aims of this study were to evaluate the energy input, energy output and energy indices in irrigated and dry-land wheat farms under different climatic conditions in Kermanshah Province. Data were collected from irrigated and dry-land wheat growers by using a face-to-face questionnaire during 2012-2013. The results showed that, regardless of climatic conditions, total energy input in irrigated and dry-land wheat farms was 52444 and 15612 MJ ha-1, respectively. Among irrigated wheat farms, the highest and the lowest energy inputswere calculated in aridwarm (60157 MJ ha-1) and wet-moderate (48083 MJ ha-1) climates while, in dry-land wheat farms, these were calculated in semiarid-cold (15295 MJ ha-1) and wet-cold (16263 MJ ha-1) climates, respectively. In irrigated wheat farms the highest energy output was 174289 MJ ha-1 for a semiarid-cold climate and the lowest was 11494 MJ ha-1 for an arid-warm climate while, in dry-land wheat farms, the highest was 70806 MJ ha-1 for a semiaridwarm climate and the lowest was 36955 MJ ha-1 for an arid-warm climate. Energy use efficiency was about 19.9% higher in dry-land farms than in irrigated ones. The highest energy use efficiencyin irrigated and dry-landwheat farms was 3.5 (in a semiarid-cold climate) and 4.4 (in a semiarid-warm climate), respectively. The highest energy productivity in irrigated farms was 0.11 for wet-cold and semiarid-cold climates while it was 0.11 for wet-moderate and semiarid-cold climates in dry-land farms. Based on our results, dry-land wheat farms had higher efficiency and productivity compare to irrigated wheat farms.