Study on energy efficiency in corn production of Iran

The aims of this study are determining the energy use, qualitative analyzing of energy flow and also investigating energy efficiency by Data Envelopment Analysis (DEA) in corn production of Iran during a seven years period. Results indicated that the average of total energy input increased from 40.98 GJ ha(-1) in 2001 to 63.64 GJ ha(-1) in the year of 2007. Similarly, the average of total output energy rose from 89.03 to 107.54 GJ ha(-1) in the same years, respectively. Also the results showed that average energy use efficiency, energy productivity, specific energy and net energy gain in the studied period was 2.59, 0.17 kg MJ(-1), 7.24 MJ kg(-1) and 51.34 GJ ha(-1), respectively. DEA considered the yield (kg ha(-1)) as output and three major energy inputs; fertilizers, diesel fuel and machinery as input of 10 provinces in each year. Findings revealed that average energy efficiency score was 90.26%. There is impermanent trend in growth of energy efficiency in corn production of Iran, which needed to further analysis in future studies to realize relevant fluctuations in corn farming. (C) 2011 Elsevier Ltd. All rights reserved.