The main aim of this study was to determine and discuss the aggregate of energy use and greenhouse gas emission (CO 2, N 2O, and CH 4) for sugar beet agroecosystems in western of Iran. For this propose data was collected by using questionnaires and face to face interview with 50 farmers. Results showed that total inputs and output energy were 49517.2 and 1095360.0 MJ ha -1, respectively. Energy use efficiency was 22.12. Total CO 2, N 2O and CH 4 emissions due to chemical inputs were 2668.35, 22.92 and 3.49 kg, respectively. In sugar beet farms total global warming potential (GWPs) was 9847.77 kg CO 2eq ha -1. In terms of CO 2 equivalents, 27% of the GWP s come from CO 2, 72% from N 2O, and 1% from CH 4. In this research input and output carbon were 29340.0 and 2678.6 kg C ha -1, respectively. Hence, carbon efficiency ratio was 10.95.
