جستجوی مقالات مرتبط با کلیدواژه « Life Cycle Assessment » در نشریات گروه « آب و خاک »

Today, the increase in food demand has led to an increase in energy use, which has some environmental consequences such as air pollution and global warming. Irrigation is one of the energy-intensive operations in agriculture, which consumes great part of energy inputs and has harmful environmental effects. Applications of modern methods of irrigation in agriculture can be considered from different aspects. So, the aim of this study was to evaluate the energy and environmental indicators of walnut orchards under surface and pressured irrigation methods. The required data, including information about inputs and energy consumed in walnut orchards, were collected using questionnaires and face-to-face interviews in Shahr-e Kord and Saman region of Chaharmahal and Bakhtiari province. The collected data belonged to the production period of 2021–2022. The averages of total energy consumed for walnuts production in pressured and surface irrigation systems were 29573.53 and 25058.46 MJ ha−1, respectively. This shows that despite less water consumption in the pressured irrigation system, the total energy input in this irrigation system is more than the surface irrigation system. No significant difference was observed regarding the performance of walnut in the two mentioned irrigation systems. The inputs energy consumption in the walnut production with the pressurized irrigation system were highest for plastic and farmyard manure (about 32% and 15%, respectively); while in surface irrigation system, the share of nitrogen fertilizer and farmyard manure were highest (about 30% and 25%, respectively). Energy ratio of walnut production in surface irrigation systems was computed as 3.58, while the corresponding value in pressured system was 2.77. In other words, surface irrigation had better conditions in terms of energy indicators. The LCA results of walnut production showed that in the two irrigation systems, the greatest effects in human health and the ecosystems are from on-farm emissions. In general, the investigation of the environmental indicators of walnut production in the two irrigation systems showed that the use of the pressured irrigation system reduces the environmental damage.

The purpose of this study was to investigate the environmental impacts of sugarcane production in Hakim Farabi Agro-Industry Company through life cycle assessment method in the 2019 crop year. The production of one ton of sugarcane considered as the functional unit. The required data was collected through face-to-face interviews with managers and experts. The results indicated that diesel fuel, electricity, urea fertilizer and direct field emissions from sugarcane cuttings had the greatest effect on all sectors in the studied effect groups. The evaluation showed that Marine aquatic Ecotoxicity released 103447.86 kg 1, 4-DB per one ton of sugarcane which has the highest potential for environmental damage. Therefore, three scenarios were defined to evaluate the effects of sugarcane cultivation on the impact categories in order to reduce water consumption, reduce fertilizers and chemical pesticides consumption and reduce electricity and diesel fuel consumption. The emission rate of this impact category after applying the first, second and third scenarios is estimated to be 99714.6, 95628.02 and 91894.77 kg 1, 4-DB per one ton of sugarcane, respectively. N2O, CO2 and CH4 greenhouse gas emissions were estimated to be 0.915, 261 and 0.506 kg, respectively. After applying the scenarios, CO2, CH4 and N2O emissions were estimated as follows: N2O emissions were 0.871, 0.827 and 0.784 kg, respectively, CO2 emissions were 251, 240 and 230 kg, respectively and CH4 emissions were 0.491, 0.475 and 0.460 kg, respectively.

Iran is one of the countries with the highest production of greenhouse gases in the world, which according to estimates is a significant part of these effects are related to agricultural activities. There are various methods for assessing the environmental impact of agricultural activities. Life cycle assessment is one of the methods for assessing the effects of sustainability that has been developed based on the product production process. Existing methods for assessing the effects of life cycle and determining the effects of agricultural activities are determined by classifying and modeling the evaluation and possible changes in soil quality indicators as a result of agricultural activities in the field. The main purpose of this study is to investigate the environmental effects of the forage maize production system using the Life Cycle Assessment (LCA) method in order to better manage and control these effects.

The study area is an educational farm of the University of Tehran with an area of 260 hectares. The required information was collected through interviews with field experts. The amount of inputs used and the emission of pollutants in several groups of effects including global warming, eutrophication, acidification, surface water poisoning and ozone depletion, classification per functional unit (one ton of forage corn) are determined and their effect on the exchange life cycle. Life cycle evaluation calculations were performed by Sima Pro software.

The results showed that (1): The most environmental degradation due to forage maize production is related to surface water pollution with a value of 1.94×10-13 kg, 1,4-DBeq that chemical fertilizers and irrigation have the most effect on this pollution 1.33×10-13 and 4.96×10-14, kg 1,4-DBeq, respectively: (2): The value of the environmental index is 2.19×10-13 points or 0.219 picopoint. It was calculated that the normalized values of the effect groups are due to the production of fodder corn, which is calculated by multiplying the total amount of contamination of each effect group by the normalization and weighting factors, specific to each effect group. The lower the value and the closer it is to zero, the less environmental impact of the product is less.

Using different methods of crop management such as the use of organic inputs, rotation, nitrogen-fixing plants, and tillage, at least based on the using of low input principles to reduce these environmental effects and also by selecting appropriate methods of irrigation yield and optimal crop yield management environmental degradation reduced these operations. The solution that can be proposed and implemented to reduce the effects of this operation is to use different methods of crop management such as the use of organic inputs, rotation, nitrogen-fixing plants, and tillage at least, based on the use of minimizing principles to reduce these environmental effects. By selecting appropriate methods for irrigation and optimal management of water consumption while increasing crop yield, the environmentally destructive effects of this operation were reduced.

Nowadays, around the world, environmental impacts, as one of the most important dimensions of sustainable development, play a significant role in strategic decision makings. Water resources management is one of the most sensitive measures due to its bi-directional relationship with sustainable development and also as a facilitator of this path, especially in arid and semi-arid regions. One of the main purpose of the LCA approach is to assess the environmental impact of emissions. In this study, environmental compatibility of mechanical watershed management measures to manage water resources is investigated by using this approach. Therefore, material flow, energy and environmental impacts of all stages of the life cycle of one unit of flood spreading system (located in Daefeh watershed in Rafsanjan plain) were analyzed based on IMPACT 2002+ method available in the Simapro software. The results showed that the earthen structure of the flood spreading system with 8.37 kPt environmental impact is the hot spot of this system (Mostly due to the earthworks), including 91.34% of environmental burdens in the construction phase and 55.2% of the total emission effects. The findings of this research showed that the environmental consequences of emissions during the life cycle of this system were 15.2 kPt. Construction process stage (with the highest amount of environmental burdens in each impact category except for resource depletion) 39.2%, use stage 31.3%, extraction and productivity of materials 23.3% and transportation stage 0.93% of Environmental burdens were allocated in this study. The environmental consequences of emissions in the categories of adverse effects on human health, climate change, resource depletion and ecosystem depletion of the flood spreading system are 6.63, 3.54, 3.06 and 1.94 kPt, respectively. Also the results of this study will be useful for evaluating the environmental effects of different structures. Finally, it is suggested that in the integrated watershed management, which is responsible for protecting our nation's natural resources, life cycle assessment approach be developed and the green building approach could be implemented, such as selecting the design discharge with environmental considerations, selecting quantities and types of environmentally friendly materials.