Emergy evaluation of Yaghuti grape of Sistan

The present study uses emergy methodology to assess environmental performance of Yaghuti grape production of Sistan. In Sistan, grape production is very important for the region in terms of both export to other provinces of Iran and domestic consumption. The renewable resources comprising free renewable local resources including sunlight, rain and wind and non-renewable including soil, and renewable purchased inputs embracing human labor, chemical fertilizer including nitrogen, phosphorous and potassium, and chemicals were the input used to estimate emergy indices. The analyses showed that the total emergy input was 1.94 × 1016 seJ, and approximately 43.41% and 23.16% were from human labor and irrigation water, respectively and followed by nitrogen fertilizer with quota of 11.32%. Emergy indices of grape production are as follow; emergy yield ratio: 1.31, emergy investment ratio: 3.25, environmental loading ratio: 0.541 and emergy sustainability index: 2.42, indicating that grape production system is sustainable and is less stressful on the environment in comparison with other research. It could be suggested with greater energy use efficiency through optimization of human labor, irrigation water and nitrogen fertilizer grape production could be recommended as suitable crop for Sistan region.