The Main Differences of Irrigated and Rainfed Barley (Hordeum vulrare L.) in Term of Pollutants Emissions in Khorramabad Using LCA

Expanding the global population and their requirement for water, food, and energy is a challenge that is compounded by increased pressure on natural resources. The decision on how and to what extent humans need to consume resources, requires precise and sophisticated scientific research and analysis. In this study, Life Cycle Assessment (LCA) methodology has been used. According to this method, it is possible to measure any performance of any given farm on the basis of the number of inputs that the farmer will provide to the plant and the outputs of it. To evaluate the effects of a production process, a goal and scope of the study should be explained, then it can be used to assess a life cycle inventory and to carry out an impact assessment. The goal of this study was to compare the environmental effects of irrigated and rainfed barley in Khorramabad.

The LCA includes the definition of the goal and scope, the analysis of the inventory, the impact assessment, and the interpretation of the results. The data was collected from farmers through questionnaires. The selection of impact assessments should reflect the comprehensive set of environmental issues associated with the product system under study, taking into account the goal and scope. The designed functional unit for the present study is to produce one ton of grain yield. SimaPro and ecoinvent-3 are used for LCA.
For investigating uncertainty and measuring random data, the Monte Carlo statistical method is used to prevent the exponential growth of data. To access the Monte Carlo method, the square or second power of geometric standard deviation must be estimated and it is indicated by the GSD2 method.

The great difference between irrigated and rainfed barley was due to inputs of electricity and irrigation. More energy consumption in irrigated crops resulted in higher yield at this condition. The amount of greenhouse gases (GHGs) emissions in producing one ton of irrigated and rainfed barley was equivalent to 1112.069 and 699.96 units per kg CO2 production, respectively. The potential for greenhouse gas emissions has been reported by researchers in irrigated and rainfed barley equivalent was to 898.24 and 604.66 units per kg CO2 production, respectively.Nitrate and phosphate are essential for plant life, but increasing their concentration in the water body causes excessive growth of algae in freshwater. Further, this will reduce the amount of oxygen in the water and ultimately lead to the deterioration of the ecosystem. The potential of eutrophication in the current study in Khorramabad for one ton of irrigated and rainfed barley was equivalent to 2.66 and 2.71 units per kg po4 production, respectively. The highest emission associated with eutrophication has been reported in wheat farms using agricultural machinery.Increasing mechanization and the use of fossil fuels contribute to increasing GHGs emissions. This problem will not affect impact assessment and in addition to increasing the potential of global warming. Therefore, any operation affects all environmental impacts and should be considered as a management solution to reduce them. The ozone destruction potential is represented by the reference of CFC-11 unit per kg production. A large number of emission factors associated with this environmental impact from the use of pesticides and herbicides during the agricultural process. CFCs are the most important substances that have the property of destroying the ozone layer (Guinee, 2002). In the present research, the difference in the potential for destruction of the ozone layer is evident in the production of irrigated barley and rainfall barley.

The environmental impact assessment for the production of one ton of barley has been calculated, but production is important. In the present study, considering that environmental production and release of pollutants in rainfall barley is far less compared to rainfed. Therefore, according to the research findings, corrective management for the production of barley should be applied to both irrigated and rainfed barley. Managing the use of pesticides and fertilizers is important. Properly integrated management such as rotation can be successful in reducing the application of pesticides and fertilizer.