عنوان مقاله [English]
Earth's atmosphere plays an important role in preventing the temperature decrease. One of the principal factors of environmental pollution and the main source of earth's climate and biodiversity changes is greenhouse gas emissions from various sources, particularly agricultural sector. Agriculture sector is considered as a major source of greenhouse gas sequestration, including methane, nitrous oxide, carbon dioxide, ammonia, and nitric oxide. One of the most important sub-sectors of agriculture that produces greenhouse gases is agronomy. Nitrous oxide is one of the most important greenhouse gases mainly produced through agriculture. About 70 percent of N2O emitted into the atmosphere from soil, obtained from biomass. The total cultivation of pulses i.e. chickpea, beans and lentils, is equal to 845,848 hectares. In other words, pulses with share of 6.95 percent of the total cultivation, is one of the most important crop productions. In this study, the amount of greenhouse gas emissions of nitrous oxide (N2O) and carbon dioxide (CO2) from the production of Iran’s pulses (including chickpea, beans and lentils) was calculated using the GHGE Model at 2011-12.
Materials and Methods
In this study the emissions of CO2 and N2O, were measured using Greenhouse Gas Emissions Model (GHGEM). This model was used to estimate greenhouse gas emissions from activities directly and indirectly related to agriculture production and the effects of mitigation measures to reduce greenhouse gas emissions. To estimate the total production of N2O and CO2 in the agricultural ecosystem, 2011-12 crop year data reported by the Ministry of Jihad Agriculture were used. In addition, the provinces organized into different classes based on the production and emissions scale and their condition using means comparison test.
Results and Discussion
The total amount of N2O and CO2 emissions from pulses crops including chickpea, beans and lentils were estimated. Fars and Bushehr provinces, with production of 79.271 and 0.004 ton of N2O emission were the highest and lowest N2O producers, respectively. In addition, the Lorestan and Bushehr provinces respectively, with production of 10327.833 and 1.33 ton of CO2 had the highest and lowest annual production of CO2 emissions. Based on the results, Lorestan and Fars provinces had the largest share of emissions from pulses. In other words, these provinces had approximately 20 percent of N2O and CO2 emissions. Total N2O and CO2 emissions from the Iran’s pulses farms, was 361.849 and 50948.71 ton, respectively. However, Lorestan with production of 10405.7 tons of N2O and CO2 was the largest producer of greenhouse gas N2O and CO2 in Iran. The total amount of N2O and CO2 emissions from pulses crops was estimated 51310 ton. One of the best methods for analyzing greenhouse gas emissions in different provinces was comparing the emissions base on per unit of products level. With regard to the comparison, Isfahan province with the release of 1.64 ton per hectare had the highest level of N2O emissions in comparison with other provinces. In fact, Isfahan province with the largest consumption of nitrogen fertilizer was the largest producer of N2O per unit area. In addition, Bushehr province with the release of 66.5 ton per hectare had the highest level of CO2 emissions in comparison with other provinces. Fars and Lorestan provinces had the highest environmental costs caused by N2O and CO2 emissions, respectively. The environmental cost of N2O and CO2 release in these provinces were estimated roughly 13900 and 179,285$ (or 0.48 and 6.185 billion rials), respectively. Also, Bushehr province had the minimum environmental cost of N2O and CO2 emission. Totally, Lorestan province had the largest environmental cost of greenhouse gas N2O and CO2 emissions from pulses production that imposes on the environment. Eastern Azerbaijan, Western Azerbaijan, Kurdistan, Kermanshah and Lorestan provinces with a share of 66 percent were as the major producer of pulses, had the highest cost of environmental N2O and CO2 emissions.Total costs of environmental of N2O and CO2 emissions from the Iran’s pulses production was estimated about 947,971$ (32.705 billion rials).
In this study, according to the diversity of agricultural activities and greenhouse gas emission of these activities, the greenhouse gas emission of CO2 and N2O were estimated considering the pulses farms (i.e. chickpea, beans and lentils) under the crop production.Results showed that Fars and Bushehr provinces, with production of 79.271 and 0.004 ton of N2O were the highest and lowest N2O producers, respectively. Also the Lorestan and Bushehr provinces with an annual production of 10327.17 and 1.33 ton of CO2 were the highest and lowest CO2 producers, respectively. The total environmental costs of N2O and CO2 emissions was estimated about 947,971$ (32.705 billion rials). In addition, the most important factor of N2O and CO2 emissions of the crops production activities was crops cultivation. However, due to the influence of variables such as the use of nitrogen fertilizers, crops residue remaining of products on the farms and annual fallow of N2O and CO2 emissions in production of pulses, applying modern farm management strategies, management and increase the efficiency of nitrogen fertilizers used on farms and developing the emission reduction policies such as carbon sequestration was proposed to the decision makers of this scope. Also considering that, the cultivation of pulses was the main source of greenhouse gas of N2O and CO2 emissions, environment’ tax of greenhouse gas emission on level of production in compensation environmental costs due to the release of such pollutants can be useful.
Key word:Carbon dioxide, Greenhouse gases emission, Nitrous oxide, Pulses