کارآیی انرژی و بهره‌وری در نظام‌های تولید سیب‌زمینی و چغندرقند استان اصفهان

A study was conducted in 2009/2010 cropping season in order to determine energy input/out put and productivity of potato and sugar beet production systems in Isfahan province, Central Iran. The data used in this study was based on data collected from growers by using a face to face survey. Total energy consumption and total out put enegy in potato production systems were calculated to be about 84633 (56.4% direct energy, 43.7% indirect energy, 33.9% renewable and 66.1% non renewable energy) and 119917 MJ ha-1, respectively. These values in sugar beet production systems were 61862 (66.4% direct energy, 33.6% indirect energy, 23.2% renewable and 76.8% non renewable energy) and 563645 MJ ha-1, respectively. The majority of energy in potato production systems was consumed as disel fules (33.7%), irrigation water (14.3%), nitrogen fertilizer (14.1), and seed (13.2%) and in sugar beet production systems were consumed as disel fules (40.5%), irrigation water (16.4%) and nitrogen fertilizer (15.9). The energy use efficiency (output/input ratio) in potato and sugar beet production systems were 1.42 and 9.11, respectively. Gross and net income were estimated to be about 5486 and 4270 in potato and 2126 and 958 $ ha-1 in sugar beet farms, respectively. Benefit to cost ratio and productivity in potato were 2.2 and 7.2 kg $-1 and in sugar beet fields were 1.33 and 11.6 kg $-1, respectively. Even though a higher economic profitability was obtained in potato than in sugar beet production system, however, aconsiderably higher energy use efficiency was achieved in sugar beet production system.