assessment of energy indices and optimizing energy consumption in greenhouse strawberry production: a case study of savojbolagh in alborz province

savojbolagh is the main region of hydroponic greenhouse agriculture in iran and is of the capacity to produce the highest in greenhouse production strawberry. the aims followed in this study were to calculate the energy use pattern and determine the relationship between energy input in greenhouse strawberry production and its yield through a linear programming model as based on data envelopment analysis (dea). technical efficiency of greenhouses were calculated and target input energies optimized. results indicated that greenhouse strawberry production consumed a total energy of 800 gj ha-1 with a specific energy of 12.5 mj kg-1calculated. linear regression analysis indicated that the impacts of diesel fuel, fertilizer, electricity and human labour were significant on yield. these effective inputs were assumed as inputs while yield as an output in the model of dea and the technical efficiency of a greenhouse (in input oriented variable return to scale model) estimated. energy technical efficiency of strawberry producing greenhouses was estimated as 0.93 and the maximum possible contribution to the total energy savings was estimated 61% that could come from diesel fuel saving. a determination of real and target energy inputs in inefficient greenhouses revealed that 16% of resources could be saved by raising the performance of these greenhouses to their highest possible level.