Economic assessment of energy consumption and greenhouse gas emissions from wheat production in Ardabil provience

Introduction:
Today, the agricultural sector is dependent on energy consumption in order to respond to the growing demand for food and etc. The efficient use of inputs in agriculture lead to the sustainable production and help to reduce the fossil fuel consumption and greenhouse gases emission and save financial resources. Furthermore, detecting relationship between the energy consumption and the yield is necessary to approach the sustainable agriculture. It is generally accepted that many countries try to reduce their dependence to agricultural crop productions of other countries. The being Independent on agricultural productions lead to take more attention to modern methods and the objective of all these methods is increasing the performance with the efficient use of inputs or optimizing energy consumptions in agricultural systems. The purpose of this study was to determine the amount of inputs and production performance, energy inputs and energy consumption, energy indices, and the environmental impacts of wheat production systems.
Material and methods:
This study was carried out in Ardabil province of Iran. To achieve these objectives, data were collected from 100 irrigated wheat farms selected from three counties including Parsabad, Bilesavar, and Ardabil during 2017-2018 using a random sampling method. Energy consumption in wheat production was calculated based on direct and indirect energy sources including human, diesel fuel, chemical fertilizers, pesticides, machinery, irrigation water, electricity and wheat stalk. Energy values were calculated by multiplying inputs and outputs per hectare by their coefficients of energy equivalents. Renewable energies include machinery, wheat stalk, chemical fertilizer while non-renewable energy consisted of machinery, chemical fertilizer, electricity and diesel fuel. Energy values were calculated by multiplying inputs and outputs per hectare by their coefficients of energy equivalents.
Results and discussion:
The results indicated that the total energy input was 38755.34 MJ ha-1, of which approximately 37.38% and 19.04% were produced from nitrogen fertilizers and diesel fuel, respectively. Approximately 39.03% of the total energy inputs used in wheat production was the direct energy, while the remaining 60.12% was indirect. Also, the results showed that energy use efficiency for grain production and biological yield of wheat was 1.67 and 1.99, respectively. Energy efficiency was estimated 0.116 and 0.142  MJ Kg -1. Total emissions of CO2, N2O, and CH4 from wheat farms were 1271.52, 517.14 and 1.65 kg ha-1, respectively. Gross value of production and Total production cost Was obtained 52268792 and 39015747. Benefit-cost ratio was obtained 1.52 and fixed and variable production cost were 54.45 and 45.6, respectively.
Conclusion:
The global warming potential was estimated 161620.14 kg CO2e ha-1. Direct, indirect, renewable, and non-renewable energy forms had positive impacts on the output level. It seems that management systems based on a low input system, including organic fertilizers, No tillage and minimum tillage, could be regarded as an alternative management strategy for  reducing problematic environmental impacts.