عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Energy method of evaluation is widely employed in analyzing problems associated with sustainable agriculture. In this study, energy ratio (ER) of dryland wheat for three regions of Eghlid township was quantified. The total cropping area of Eghlid is nearly 8282 hectares comprised of: Khosrowshirin (5000 ha), Sedeh (1682 ha) and Dezhkord (1600 ha). The corresponding values of wheat yield in these subareas are 1, 1.02 and 0.9 ton/ha, respectively. In this township, dryland cropping is performed via two methods: mechanized (using moldboard plow and then deep seed drilling) vs semi-mechanized (manual seed broadcasting, or using a seed broadcaster and then applying the moldboard plow). In this study, the equivalent energy inputs and outputs for either one of the methods was evaluatted and then the corresponding energy ratio determined. Inputs were: fertilizer, seed, pesticide, fuel, equipment, labor, while outputs being grain yield and straw. Grain energy ratio for Khosrowshirin, Sedeh and Dezhkord were obtained as 1.068, 1.19 and 0.91, respectively, while the corresponding values related to both grain and straw (total biological output) were 1.61, 1.80 and 1.36, respectively. Consequently, for the township, the corresponding mean values related to grain vs both grain and straw were calculated as 1.06 and 1.60, respectively. Input energy of dryland wheat was found to be 12.49 GJ/ha and total output energy (grain and straw) was 20.056 GJ/ha leading to the net energy gain (NEG) of 7.54 GJ/ha. Mean values of fertilizer, fuel seed, equipment, pesticide, and labor were becomes evident 57.5%, 28.4%, 12.1%, 1.25%, 0.38%, and 0.02%, respectively. It becomes evident that the input items fertilizer and fuel have dedicated to themselves the highest values of energy consumption the magnitudes of which should be optimized for implementation of an efficient management. Improportionate consumption of these inputs not only increases the production costs involved but also adds to the pollution of the atmosphere, soil and water resources as well.