ehsan khodarezaie; Korous Khoshbakht; Hadi Veisi; Mohammad Reza Nazari
Abstract
IntroductionEnergy use in agriculture has grown faster than other sectors of the global economy. In developing countries, most agricultural systems consume significant amounts of energy to increase production and food security. Energy consumption leads to the emission of greenhouse gases and environmental ...
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IntroductionEnergy use in agriculture has grown faster than other sectors of the global economy. In developing countries, most agricultural systems consume significant amounts of energy to increase production and food security. Energy consumption leads to the emission of greenhouse gases and environmental pollutions in the agriculture sector. Besides, the use of fossil fuels in the production process and transfer of inputs emits greenhouse gases, which in turn cause global warming and climate change. Analyzing and good understanding of energy flow and Greenhouse Gas (GHG) emissions in agricultural production systems can help to optimize crop management practices thereby reducing environmental problems. Iran's average energy consumption is three times higher than the world average.Groundwater is the main source of agricultural water in arid and semi-arid areas. Electricity used in irrigation pumps consumes a large of energy and emits GHGs. Qazvin plain is one of the most important agricultural plains in Iran, which along with the use of groundwater, has the largest irrigation canal network in the country. Differences in agricultural water supply sources can lead to differences in energy consumption and greenhouse gas emissions as electricity and other inputs may be affected. Wheat, barley, alfalfa and maize silage are major crops in Qazvin plain. Alfalfa and maize silage need relatively a high irrigation water requirement. This paper evaluates the energy flow and Global Warming Potential (GWP) of alfalfa and maize silage farms with two different water supply sources (well and canal) in Qazvin plain.Materials and MethodsThe data were collected through face-to-face interviews with farmers in the year 2018. Energy indices were estimated based on the analysis of farm inputs and outputs. Global Warming Potential was calculated using the Life Cycle Assessment (LCA) method and SimaPro 8.2 software. GHGs were calculated using the conversion coefficients presented by the IPCC GWP 100 method. Results and DiscussionThe output energy values of maize silage and alfalfa were calculated as 232726, 191812 MJ ha-1 for well water irrigation system and 234167 and 248060 MJ ha-1 for the canal water irrigation, respectively. Results showed higher net energy values for alfalfa (172778 MJ ha-1) and maize silage (167618 MJ ha-1) in canal water irrigation system compared to well water irrigation (131300 MJ ha-1 and 60112 MJ ha-1 for corn silage and alfalfa, respectively) mainly because of the relatively lower input energy. The results showed that the highest and lowest values of input energy were related to alfalfa production with well water irrigation (131700 MJ ha-1) and maize silage with canal water irrigation (66548 MJ ha-1), respectively. Also, the energy use efficiency of maize silage (3.5) and alfalfa (3.3) were higher in canal water irrigation systems compared to well water irrigation systems (2.3 for maize silage and 1.46 for alfalfa). In the well water irrigation systems, GWP was calculated to be 7466.9 kg CO2-eq ha−1 and 7995.7 kg CO2-eq ha−1 for maize silage and alfalfa, respectively. These values were 5533.3 kg CO2-eq ha−1 and 4947.6 kg CO2-eq ha−1 for maize silage and alfalfa in the canal water irrigation systems, respectively. Electricity and direct emission showed the highest share of total energy consumption and GHG emission.ConclusionGenerally, our results showed that energy consumption and GWP were lower in the canal irrigation systems than well irrigation systems mainly as a result of electricity used for water pumping in well irrigation operations. It can be inferred from the present study that for efficient use of resources and decreasing environmental problems in the study area, practices such as optimal management of irrigation water, conservation tillage, and optimal management of chemical fertilizers can help to achieve these goals.
Salah Mafakheri; Hadi Veisi; Korous Khoshbakht; Mohammad Reza Nazari
Abstract
Introduction: Today, agricultural resource management is a fundamental task for managers and planners due to the need to address the challenging issues between the supply and demand sectors. Accordingly, many researchers have emphasized that water, food, and energy in the world are experiencing significant ...
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Introduction: Today, agricultural resource management is a fundamental task for managers and planners due to the need to address the challenging issues between the supply and demand sectors. Accordingly, many researchers have emphasized that water, food, and energy in the world are experiencing significant stress and scarcity, and demand for these resources will increase significantly in the coming decades. The main purpose of this study is to provide a method for decision-makers in analyzing the link between water, energy, and food in the crop production system at the regional level and to perform a quantitative evaluation of it, which can be used to create a suitable and optimal cultivation pattern with pay attention to the available resources of the area.Material and methods: The present study was conducted to evaluate the water-food-energy relations of agricultural products in Dehgolan County. The required data were collected through face-to-face interviews with farmers and agricultural jihad statistics. The method of this paper was based on six indicators of water and energy consumption, mass productivity of water and energy, and economic productivity of water and energy. Based on these indicators, a water-food-energy index (WFENI) was calculated for each product. This method was applied to evaluate 7 main crops of wheat, potato, alfalfa, cucumber, barley, carrot, and rapeseed in water farms of Dehgolan County in the years 2019-2020.Results and discussion: The results of data analysis showed that alfalfa and potatoes had the highest water consumption (13131 cubic meters per hectare) and energy (85404 megajoules per hectare), respectively. Barley had the lowest water consumption (4197 cubic meters per hectare) and energy consumption (31394.4 megajoules per hectare). The use of chemical fertilizers had the largest share in the energy sector (except alfalfa). In the alfalfa crop, due to high mechanization operations, machinery had the largest share of energy consumption. Carrot was the most productive in water consumption (7.08 kg/m3) and energy (1.03 kg/mJ). Also, the lowest water and energy efficiency for canola (0.44 kg/m3) and energy (0.06 kg/MJ) were obtained. In the economic index of water and energy productivity, the highest values were obtained for cucumber (92959 Rials per cubic meter) and carrot (13202 Rials per megajoule), respectively. The lowest economic efficiency of water and energy was calculated 1549 Rials per cubic meter for carrots and 10688 Rials per megajoule for canola. This study showed that the WEFNI was calculated 0.86, 0.73, 0.51, 0.41, 4 / 0, 0.3, and 0.26 for carrot, cucumber, potato, wheat, barley, canola, and alfalfa crops , respectively, in Dehgolan city. Carrots received the highest WFENI score (best score) and alfalfa the lowest (worst score). Although potato, which is one of the water crops with a high level of cultivation in the region, had high water and energy consumption, due to its high physical productivity and economic productivity, it obtained the third score of the total index.Conclusion: In this study, agricultural products were compared based on indicators of water and energy consumption, physical productivity of water and energy, and economic productivity of water and energy. Based on these indicators, the water, food, and energy link index were calculated. The results can also be used as an effective tool to determine appropriate strategies for cultivation patterns, management of water and energy resources in the region, and a basis for planning and agricultural policies in the county.
Maryam Akbarpoor; Hadi Veisi; Abdolmajid Mahdavi Damghani; Mohammadreza Nazari
Abstract
Introduction: Localization of the food system has become in line with sustainable agriculture for many reasons including ecological advantages, economic benefits, and social considerations. Yet the question is that to what extent food can be locally produced. To answer this question, the concept of ...
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Introduction: Localization of the food system has become in line with sustainable agriculture for many reasons including ecological advantages, economic benefits, and social considerations. Yet the question is that to what extent food can be locally produced. To answer this question, the concept of foodshed can be considered. The concept provides a framework for analyzing local food production at any scale. The foodshed is a land that can supply all or parts of a given population's nutritional needs within a given geographical area. So far, no foodshed study has been conducted in Iran, so this study proposed a model to study foodsheds. By taking a sustainable food system into account, the current research examined the concept of foodshed, the status of food production and consumption in Tehran Province, and the capacity of this province to meet its nutritional needs. Material and methods: The model was used in Tehran Province using a unit named "plant equivalent" to calculate and compare the amount of food produced in the study area and the nutritional requirement of the province’s population. Production of each crop (based on the plant equivalent unit) in each region was calculated by multiplying the crop cultivation land area in the crop yield. The amount of need for each plant equivalent unit in each region was calculated by multiplying the population of that area in the weight of food that is needed of a person in a year. Then, using self-sufficiency formulas, we estimated how much of the population's needs are being supported by the existing production. To calculate self-sufficiency, a concept known as threshold production was used. Calculation of threshold production was done with Matlab using conditional programming and coding. Excel, Matlab, and GIS were used in this research. Results and discussion: One of the most important achievements of the present study was the foodshed assessment of Tehran Province considering its increasing population and providing food security in this province. In the present study, which was carried out on a provincial scale, self-sufficiency in providing the desired food basket for the population of Tehran Province was 22% and the highest and lowest self-sufficiency was estimated in Pishva and Tehran counties, respectively. Self-sufficiency percent in producing crops to provide the desired food basket in Tehran Province was higher in fodder corn (100%) (self-sufficient), vegetables (79%), fruits (56%), barley straw (53%), wheat straw (45%), barley grain (16%), wheat bran (8%), wheat grain (5%), forage crops except corn (4%), rapeseed meal (0/1%), rapeseed (0/06%), respectively. However, in legumes, rice hull, root, pulp, and molasses of sugar beet, corn, and soybean meal self-sufficiency percent was estimated zero percent, meaning non-self-sufficient or total dependence. Conclusion: The results of this study indicated that the percentage of foodshed self-sufficiency in providing the desired food basket for the population of Tehran Province was 22%. Although localization has benefits, it seems that considering the small area and the overcapacity population of Tehran Province and the environmental issues (water scarcity and soil erosion), the boundaries of Tehran Province foodshed should be broadened and the foodshed radius must be increased.
Parichehr Najafi; Masoud Fehresti-Sani; Mohammad Reza Nazari; Akram Neshat
Abstract
Introduction: Considering the high transportation costs of sugar market (produced by sugar beet), the logistic management of its supply chain is of particular importance, which can reduce costs as well as air pollutants, and help with locating facilities, on-time delivery of services and customer satisfaction. ...
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Introduction: Considering the high transportation costs of sugar market (produced by sugar beet), the logistic management of its supply chain is of particular importance, which can reduce costs as well as air pollutants, and help with locating facilities, on-time delivery of services and customer satisfaction. Up until now, few studies have been conducted on the optimization of the distribution network of agricultural products in the supply chain, taking into account the economic and environmental impacts. Therefore, the present study aimed to optimize the sugar beet’s distribution network from production areas to refineries in Iran’s sugar supply chain and determine its economic and environmental impacts. In this study, in addition to comparing transport costs in the current and optimal distribution situation, changes in fuel consumption per shift in sugar beet’s distribution, reduced emissions due to the reform of the transportation network and its economic benefits in the country were also evaluated. Material and methods: The present study was carried out using data obtained from Iran's statistics center in 2014 for 10 provinces producing sugar beet’s sugar, including Western Azerbaijan, Kermanshah, Khuzestan, Fars, Yasuj, Lorestan, Semnan, Qazvin, Khorasan Razavi, and northern Khorasan and 24 demand centers. This study used a linear programming model to consider the simple transport model to analyze the data using GAMS software. Results and discussion: The implementation results of optimal transportation plan showed that the implementation of the proposed program decreased the costs of about 4.5 billion USD, equivalent to 3.84%. Also, the implementation results of the optimal transportation plan considering the environmental impacts indicated two million and 177 thousand liters reduction of gasoline and 5.7 billion rials increase in environmental benefits. Conclusion: It can be concluded that implementing an optimal transportation plan may reduce transportation costs as well as environmental pollution. Therefore, implementation of an optimal plan resulted in the reduction of transportation costs and consequently, on the final price of sugar. Based on results, it is suggested that, during transportation planning in the sugar supply chain, the proposed model in this study should be used for sugar beet transport.
Maryam Foroughedin; Mahdi Jalili Ghazizade; Maryam Mirabi; Mohammad Reza Nazari
Volume 15, Issue 4 , January 2018, , Pages 177-192
Abstract
Introduction: Liner is one of the most important components of waste landfills, which its main function is to limit the penetration of leachate caused by the waste from landfill base. Since the cost of a lining system is a significant part of landfill’s total cost, therefore, it is necessary ...
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Introduction: Liner is one of the most important components of waste landfills, which its main function is to limit the penetration of leachate caused by the waste from landfill base. Since the cost of a lining system is a significant part of landfill’s total cost, therefore, it is necessary to design the compacted clay liner with environmental and economic considerations in the same way, which requires identification of factors affecting the construction cost of clay liner. Materials and methods: For this purpose, using the performance-based approach, the factors affecting the technical design and hydraulic performance of clay liners in preventing leachate leakage, four variables include of trench height, trench lifespan, land price and distance from the soil loanl, have been identified as the variables affecting the cost of clay liner construction. Using the HYDRUS one-dimensional model, the appropriate liner thickness was determined in the scenarios of 30, 60,180,360,720 and 1080 days for the trench lifespan. Then by defining design scenarios based on the effective variables, the cost of different parts is estimated. Results and discussion: Investigating the cost variations shows that increasing the height of the trench in different parts leads to lower costs of construction.While changes in the cost of liner construction over the lifespan of the trench first had a downward trend and then incremental pattern.The variations in total cost is affected by land cost variations and indicates the importance of land prices in assessing the overall costs of constructing the liner. Also an increase in the distance from the loan increases the cost of liner construction significantly, and if the suitable soil for lining to be located more than 100 km from the site, then the use of Geosynthetic clay liners is more cost-effective. The trench life time as a variable with less design constraint, can be considered depending on the cost of other parts. Conclution: Investigating costs in different parts of compacted clay liner construction shows the necessity of economic modeling and creation of cost functions for optimal design of compacted clay liners in every area.
Fahimeh Bahrami; Momadreza Nazari
Volume 15, Issue 3 , October 2017, , Pages 39-54
Abstract
Introduction: Policies and plans for water resources management, especially in the agricultural sector, are aimed at achieving goals such as increasing the level of self-sufficiency, reducing gaps in food, reducing crop cultivation and maximizing the economic value of irrigation water. The main objective ...
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Introduction: Policies and plans for water resources management, especially in the agricultural sector, are aimed at achieving goals such as increasing the level of self-sufficiency, reducing gaps in food, reducing crop cultivation and maximizing the economic value of irrigation water. The main objective of this research is to reduce macroeconomic objectives in the agricultural sector, reducing the food security gap (in the field of garden products) with an emphasis on optimizing water use in the agricultural sector. Materials and methods: In pursuit of this goal, the goal of maximizing the economic value of water has been used to determine the optimal level of cropping of major crops in the country and to reduce the gap between supply and demand. The methodology used in this study is a linear mathematical programming model. Required data were collected through the databases of the Agricultural Jihad Organization and the relevant departments in the relevant areas. Result and discussion: The results of the research show that, suggested cropping pattern increases the economic value of water by 20%, and the level of crops such as dates, apples, citrus, grapes and pistachios increases. Changing the cropping area of major crops in some areas, such as Khorasan, Central, Central Zagros and Khuzestan, has reduced net profit, but generally increased net yield by 19 percent, and most importantly, the amount of water saved in the whole area is equivalent to the cultivar About 6869768 thousand cubic meter. Conclusion: The results showed that considering the economic value of water in each area, instead of using a steady state value, an effective and effective cropping pattern is necessary. The proposed cropping pattern reduces the nutrient gaps and cropping water levels and saves water consumption, which, while providing a land for allocating this amount of water to the cultivation of strategic products, can have a positive effect on the sustainability of water resources In each area.
