Mohammad Bahadori - Department of Soil Science Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran,Karaj, Iran
Reza Tabatabaekoloor - Department of Biosystem Engineering, Faculty of Agricultural Engineering, Sari University of Agricultural Science and Natural Resources, Sari, Iran

Energy is a fundamental ingredient in the process ofeconomic development, as it provides essential servicesthat maintain economic activity and the quality of humanlife. Modern agriculture has become very energyintensive.This study was carried out in Mazandaranprovince in Iran and aim of investigation was energyanalysis (input-output) of apple production systems inMazandaran Province of Iran. Data were collected from55 apple farms by using a face to face questionnairemethod in 2013. The results revealed that in appleproduction systems total energy input was 34.640 MJ ha-1. The highest share of energy consumed was recordedfor N fertilizer (20.80%) which is a nonrenewableresource. Output energy was 102.973 MJ ha-1.Accordingly, energy use efficiency (output-input ratio)was 2.97, energy productivity calculated as 0.20 kg MJ-1and net energy was observed as 68.333 MJ Kg-1. Also,agrochemical energy ratio was 48.97% which is highratio of input energy in these agro ecosystems

Energy use efficiency, Energy productivity,Apple, Agrochemical, Renewable energy