Alipour A., Veisi H., Darijani F., Mirbagheri B., Behbahani A.G., 2012. Study and determination of energy consumption to produce conventional rice of the Guilan province. Res. Agr. Eng., 58: 99-106.The aim of this study was to determine the energy efficiency indices in the agro-ecosystems of the Guilan province in 2010. One hundred and twenty-seven farmers were interviewed using a particularly designed questionnaire. The inputs in the calculation of energy use in agro-ecosystems embraced labour, machinery, electricity, diesel oil, fertilizers, seeds, while rice and straw yield were included in the output. The results depicted that total input and output energy into these agro-ecosystems were about 47,604 and 90,680.04 MJ/ha, respectively. The highest energy input was related to water (38.84%), electricity (27.87%) and nitrogen fertilizer (17.5%). Energy efficiency and energy productivity in these agro-ecosystems was 2.19 and 0.064 kg/MJ, respectively, and water productivity was 0.11 kg/m 3 . The results also showed that due to application of flood irrigation in these agro-ecosystems and also water elicited from subterranean sources by electrical pump, the inputs had the largest portion among the energy inputs to agro-ecosystems that this matter increased energy use in the unit area and also reduced energy efficiency and productivity.