جستجوی مقالات مرتبط با کلیدواژه « sustainable management » در نشریات گروه « اکولوژی »

Limited water resources and population growth have made the agricultural sector more in demand than other water-consuming sectors, so today the challenge for the agricultural sector is related to food production using less water. This case study was conducted in the plains of Tehran province in 1397-98 and it is based on the information available in agricultural management of Tehran province. Therefore, the purpose of this survey is to investigate the challenges and factors affecting the sustainability of water resources management. First, we did random sampling from agricultural producers and 110 producers determined based on Cochran's formula as the sample size. The reliability of questionnaire determined between 75%-93% by Cronbach's alpha index with SPSS. Then the appropriate production function called Cobb–Douglas production function is given and using the shepherd theorem, the production cost function and then Demand function for agricultural water has been calculated. The added value of the agricultural sector was considered as a dependent variable and independent variables including economic, social and technical variables. According to the results of the correlation test, there is a significant relationship between sustainable management of water resources and the variables of economic factors and then the views of experts is at the level of 99%. There is no significant relationship between age and background of experts and water sustainability. In other words, these factors are independent of sustainable water management.

Since there are various social factors and differences between different sectors of the system, ignoring water users’ attributes and their social behavior as well as considering only the homogeneous and up-down management scheme, would not be a successful approach in sustainable water management. Agent-Based Modeling is a relatively new approach that provides helpful tools to simulate social behaviors in sustainable water management. In this study, the agriculture sector’s water use is simulated using a conceptual framework and an Agent-Based Model to study the behavior of the decision-making agents. Therefore, to prepare the conceptual model and to simulate and analyze the social behavior of water users (in three decision levels of the Government, local organizations, and farmers) to decide on the cropping pattern, the irrigation method, and consequently the water withdrawal volume, the MAIA framework has been applied. In this regard, the Agent-Based Model for a pilot study area (the Hablehroud River basin, Iran) was coded, verified, calibrated, and validated. This model had a good performance in simulating the basin’s conditions, including cropping patterns and areas, and therefore the stream flow and groundwater use. Furthermore, to assess the impacts of the government’s water conservation policies on the hydrologic conditions, different scenarios of taking and increasing water costs were defined and modeled (one to ten thousand IRR per cm of water use led to a decrease in the total water withdrawals in the range of 8-32 million cubic meters per year).

Water is one of the most valuable natural resources used in different sectors and as one of the main inputs of agricultural production, it has a special place in sustainable agriculture development. Currently, water consumption is actually higher than its supply sources, and it is the highest in the agricultural sector; therefore, sustainable management of agricultural water is necessary. The purpose of this research is to identify the most important potential and constraints of the water resources of East Azarbaijan province and to formulate appropriate strategies and strategies. Identification and analysis of strengths, weaknesses, opportunities and threats using the SWOT model. The strengths, weaknesses, opportunities and threats facing water resources of the province were identified from the viewpoint of 43 provincial water experts and university professors through a questionnaire. In order to select the statistical sample, inaccurate and targeted sampling was used. Snowball sampling was used to select target samples. In this study, the SWOT model was used to analyze the strengths, weaknesses, opportunities and threats, and the IEF and EFE matrix were formulated and formulated strategies. The results of the internal and external factors evaluation matrices showed that considering the overall final score obtained for internal and external factors, strategic strategy of sustainable management of agricultural water resources of the East Azarbaijan province is an opportunistic strategy (Mini-Maxi strategy).

The purpose of this descriptive- survey research was analysis of explaining factors of actions related to sustainable management of water resources and the factors affecting it. The statistical population of the research consisted of 5100 agricultural heads of household in the rural areas of the Komijan County, which a sample size of 300 was selected using multiple stage sampling technique. Data collected using research-made questionnaire. Content validity of the questionnaire was confirmed by a panel of experts. A pilot study was conducted to establish the reliability of the instrument. The Cronbach alpha's coefficient for main scales of the questionnaire was at an appropriate level (higher than 0.75). The results showed that five factors of management, farming, technical, control and maintenance and restoration explained about 69.83 percent of variances of actions related to sustainable management of agricultural water resources. Also, the results revealed that 68.91 percent of variances of factors affecting the sustainable management of agricultural water resources were explained by four factors, including knowledge- supportive, extension, participatory- interactional and the use of mass media.

In recent years, the effect of exogenous organic amendments on soil properties and plant growth characteristics has received renewed attention. Although the utilization of mineral fertilizers could be viewed as the best solution in terms of plant productivity, this approach is often inefficient in the long-term in tropical ecosystems due to the limited ability of low-activity clay soils to retain nutrients. Intensive use of agrochemicals in agricultural systems is also known to have irreversible effects on soil and water resources.
The use of organic and biological fertilizers are important strategies to reduce harmful effects of chemical fertilizers in sustainable management of agroecosystems.
Spent mushroom compost is the residual compost waste generated by the mushroom production industry. It is readily available and its formulation generally consists of a combination of wheat straw, dried blood, horse manure and ground chalk, composted together. It is an excellent source of humus, although much of its nitrogen content will have been used up by the composting and growing mushrooms. It remains, however, a good source of general nutrients, as well as a useful soil conditioner.
Most mineral soils contain mycorrhizal fungi, but often at levels that are too low for adequate colonization, especially in disturbed soils. Mycorrhizae are host specific and will only colonize certain plants; so in some soils, there are no native mycorrhizae that will benefit these plants. Therefore, most plants would benefit from mycorrhizae addition to the soil. Symbiosis begins when fungal spores germinate and emerging thread linke structures, called hyphae, enters the epidermis of plant roots. After colonization of the root, the fungus sends out a vast network of hyphae throughout the soil to form a greatly enhanced absorptive surface area. This results in improved nutrient acquisition and uptake by plant roots, particularly elemental phosphorus, zinc, manganese and copper and water. In return, the plant provides carbohydrates for the fungi.
In order to study the effect of mushroom compost and mycorrhiza on yield of garlic (Allium sativum L.), a split plot experiment based on RCBD design with three replications was conducted in 2010-11 growing season in research farm of Ferdowsi University of Mashhad, Iran. Mycorrhiza (Glomus mosseae) (use and non-use) and spent mushroom compost levels (SMC) (0, 20, 40, 60, 80, 100 t ha-1) were considered as the main and sub factors. In order to determine the physic-chemical properties of soil, sampling was done at a depth of 0 to 30 cm. Distance on and between rows was considered 10 and 20 cm, respectively. In order to weeds control, manual weeding was done three times. At the end of the growing season, economic yield, biological yield, plant height, shoot dry weight, bulb diameter, bulblet weight per plant, bulblet volume per plant and bulblet number per plant were measured. Analysis of variance was done with SAS Ver 9.1 software.
Result and The results showed that the effect of different levels of mushroom compost was significant on the most studied traits, but mycorrhiza had no significant effect on yield and yield components of garlic. Based on the results, highest diameter and length of the bulb and bulblets were observed in application of 100 t ha-1 SMC. The highest economic yield (12760 kg ha-1) was observed in application of 100 t ha-1 SMC, so that the application of SMC increased economic yield by 48 percent compared to control. The highest dry matter production and harvest index also were observed in application of 100 t ha-1 SMC.
Organic and biological fertilizers are among the most significant resources for development of agricultural soil quality and increase in the yield of different medicinal plants. It has been reported that this ecological inputs provide favorable conditions for plant growth and development through improvement of physical, chemical and biological properties of the soil (Cabrera et al., 2009), therefore, it can be concluded that improvement of the most studied traits in the present study were due to use of organic fertilizers.
In general, the results showed that it seems use of SMC can improve quantitative and qualitative characteristics of garlic, thus it can be considered as a suitable alternative to chemical fertilizers.

Irrigation systems have various impacts on agriculture in terms of their ecological, social and economic aspects. Understanding these effects may contribute to develop appropriate policies and strategies for sustainable agriculture. Accordingly, the present research was conducted to determine the impacts of irrigation systems development on agriculture in Tehran. A survey was undertaken with a sample of 72 experts and specialists of irrigation systems development selected using the Snowball technique as a non-probability sampling. The main research tool was a questionnaire the validity of which was reviewed by members of the expert group. Reliability of the questionnaire was obtained at 0.85. The results revealed that sustainable resource management, employee and income, environmental impacts, intuitional trust and development, mechanization, productivity, improvement of quality of life, expansion of land fields and improvement of population profile are all key impacts of irrigation systems development on Iranian agriculture. These factors could measure about 73.142 per cent of total variance.