Calculation of energy requirement and energy efficiency for production of major agricultural crops
2009
Gholami, Ahmad | Sharafi, Saeed
This study was carried out to determine the energy use in the Iran agricultural sector for the period of 1980-2005 to evaluate the impact of energy input to produce output. The inputs in the calculation of energy use include human labor, machinery, electricity, fertilizers, seeds and output energy included 16 agricultural crops yield. Energy values were calculated by multiplying the amounts of inputs and outputs by their energy equivalents with the use of related conversion factors. The energy efficiency is determined by dividing the output value by the input value. The results indicated that the total energy input increased from 55.64 x10⁹ MJ/ha in 1980 to 150.71x10⁹ MJ/ha in the year 2005. Similarly, total output energy rose from 325.56x10⁹ to 535.15x10⁹ MJ/ha in the same period. It was found that energy efficiency was declined from 5.85% in 1980 to 3.55% in 2005, which indicates that the energy input increased faster than energy output. It also indicates that the use of inputs in Iran agricultural production was not accompanied by the same results in the final product. This can lead to problems associated with these inputs, such as global warming, nutrient loading and pesticide pollution. Therefore, there is a need to choose a new policy to force producers to undertake energy efficient practices to establish sustainable production systems.
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