Energy and Greenhouse Gases Balances of Cotton Farming in Iran: A Case Study

Abstract

This study evaluated the impacts of cotton farming on the climate changes in terms of energy and greenhouse gas (GHG) emission indices. Energy consumption pattern and sensitivity of energy inputs were evaluated and share of each input in GHG emissions was determined in the form of direct and indirect emissions for cotton farms in Golestan province of Iran. The total energy input and energy output were calculated to be 34,424.19 and 41,496.67 MJ/ha respectively. The share of fertilizers by 45.0 % of total energy inputs was the highest. This was followed by energies of fuel (18.4 %) and irrigation (17.9 %) respectively. Fertilizers and fuels were also the biggest producers of GHGs in the farms with shares of 61.95 and 24.32 % of total GHGs emission. Energy ratio, energy balance, energy intensity and energy productivity were found as 1.21, 7,072.48 MJ/ha, 9.79 MJ/kg and 0.10 kg/MJ, respectively. Results of sensitivity analysis indicated that the cotton production was more sensitive to energies of seed and human labour than other inputs and an additional use of 1 MJ of each of these inputs would lead to a change in the yield by −0.75 and 0.73 kg/ha, respectively. The results also showed, in the process of cotton farming 897.80 and 1177.67 kg CO2 – equivalent of direct and indirect GHG were emitted per hectare respectively.

Keywords

• cotton
• efficiency evaluation
• energy analysis
• GHG emission