جستجوی مقالات مرتبط با کلیدواژه « راهکار » در نشریات گروه « آب و خاک »

Wheat is a strategic crop in Iran . As a result, various policies and plans have been developed and or implemented in Iran. In macro-level documents, attention to this crop as a strategic crop is still low. However, in the policies and executive plans within the system of those in charge of crop production , it is one of the main challenges and concerns and various policies and plan have been developed and implemented. Such as policies and plan to use more modern irrigation methods , more use of conservation agriculture, “mutation plan” of crop production in rainfed agriculture, various research-development plans with international research institutes, agro-technics and breeding programs, implementation of the plan to increase wheat self-reliance, increase, the productivity of cereals-based production systems, increase the yield and water productivity of wheat in wheat systems, and formulate policies and implement instructions related to encouraging the nominated farmers with high water productivity. Of the highlights of these policies and plans is the special attention to improving the production of rainfed crops and more involvement of the private sector and relevant institutions in improving the production and productivity of this crop. However, the results of this study show that the developed policies and plans have not been well documented, developed, and or codified, and are mostly in the form of official statements in the media or case reports and circulars. Moreover, reviewing the progress and monitoring of these policies and plans in regard to identify obstacles to their implementation, as well as their cross-sectional and sustainability in terms of work continuation, are some of the weaknesses and shortcomings of such policies and plans. In conclusion, recommendations and solutions of various categories including planning-policies and strategies to improve the yield and water productivity of wheat in the country are presented.

Under water scarcity conditions livestock production, because of its high content virtual water, has been one of the challenging issues in the scientific literature in this regard.A few scientific references believe that forage crops production, because of their high water requirements, make pressure on water resources of scarce-water countries.Other references are on this idea that there is to somehow exaggeration on the high water requirements of the livestock productions.Therefore, in most cases the livestock water productivity(LWP), especially when the protein content and nutritional values of livestock products and other services are considered, is comparable with the water productivity(WP) of agricultural crops. However, similar to the issues of improvement of WP in agriculture, the key point of livestock production from limited water resources is the improvement of LWP.LWP is defined as the ratio of the net benefit obtained from livestock products and other services to the water used for such productions and services. Livestock water productivity does not seek to maximise the number of livestock or the production of animal products and services. Rather, it opens opportunities to produce the same benefits with fewer animals and less demand for agricultural water. This paper reviews different views on livestock production under water scarcity circumstances considering WP and LWP improvement issues.It then deals with the definition and concepts of LWP and its methods of estimation and calculations.The paper provides some apparent values of LWP measured in different studies and elaborates the issues, difficulties, and sources of errors in this regard. Livestock production could be indicative of an efficient or inefficient use of water resources depending to the method of estimates,calculation approach, and or selected scale. Paper concludes that for the required links between livestock production and use of water resources, especially in the mixed livestock-farming systems and in basin-scale are not established well.

Climate change (CC) is an avoidable phenomenon, which is occurring in vast parts of the world, including Iran. Agriculture and crop production are among the sectors, which are affecting from CC. Although food production activities, especially animal protein production, which have high footprints of water, have been some causes, among other important and main causes of CC occurrence. The CC moreover to increasing air temperature and hence crop water requirements, cause crop yield reduction and crop production deficiency. Therefore, considering water shortage crisis in Iran country, and in order to fulfill food security objectives of the growing population, it is necessary to coincide with the CC impacts in agriculture and to take adaptation measures and approaches in these regards. However, there are two main strategies for coinciding with CC: 1. Mitigation of CC and 2. Adaptation to CC. The mitigation strategy deals with reducing greenhouse gasses (GHG) emissions, while the adaptation strategy deals with amelioration of unavoidable impacts of CC. It includes a wide range of measures, approaches, and action selected for a vulnerable system. In this paper following an in-depth review of international and national references and policies in the field of agricultural water and food security, visions and strategies of facing with CC from the mentioned aspects are elaborated. Based on results, the following strategies and measures of adapting to CC from the agricultural water management and food security aspects could be categorized as followings: 1-Reducing water consumption during irrigation, 2-  Water conservation and reducing evaporation losses from soil surface, 3-Inceasing crop yield (increasing the numerator of water productivity index-WP), 4- Reducing the economic risk through diversity in revenue, crop insurance, subsidies and other incentives, and 5-Eetablishing early warning systems and providing training and other capacity building on the subject of adaptation to CC. However, from the strategy aspects and based on the benefit to cost ratio, in short-term the managerial measures and approaches of adaptation to CC are more efficient and less costly than the other measures, i.e. infrastructural and even agronomic measures and approaches.

Due to low rainfall and unplanned distribution of time and space, Iran has insufficient surface water resources and the agricultural sector is largely dependent on groundwater. This issue, along with other technical, economic, cultural and legal issues, has caused the country's plains to be overrun in recent years and have been hit by a stagnant level and the resulting consequences of it. If quantitative and qualitative destructive effects are evaluated and quantitatively measured, then these water resources are used optimally and with proper planning based on the type and amount of complications, suitable strategies for dealing with them will be identified. In this research, the quantitative and qualitative changes of groundwater resources in the Kabodar-Ahang and Malayer plains, which are located in the sub-basins of Ghareh-Chay and Gamasiab in Hamedan province, have been investigated. For this purpose, the balance of groundwater resources, volatility of water table, salinity changes, variations in Qanats and springs, were analyzed from 1994 to 2007, and then the various complications were observed in the region. According to the results, the complications due to unauthorized withdrawals in Kabodar-Ahang and Malayer plains, respectively, include the creation of 77.8- and 61.3-million cubic meters of negative balance in the year 2005-2006, the average annual drop in water table of 1.6 and 1 M, 35.7 and 52.7% decrease in discharge volume, 75% decrease in the number of Qanats and drying of a lot of wells and Qantas. Also, other complications have caused the land to land at several points in the Kabodar-Ahang plain with an average depth of 15 m, ascending and 30% increase in silt, and an increase of 20% in urban migration. Based on this existing situation and its causes, there are some solutions that some of them are policy-making and implementation issues by government agencies, while others can be done through the. Among the effective activities that can be done by the users to improve their economic situation and protect water resources for optimal use of water resources include: 1. Activities that reduce the need for pumping water from the well, 2- Activities that prevent the pollution of groundwater resources, and (3) activities that increase production without increasing water consumption.

Development of agriculture and sustainable crop production in the arid and semi-arid regions depends mainly on improving water productivity (WP) at the field scale¡ which is referred to as water use efficiency (WUE). The WUE index is indicative of the amount of crop produced per unit amount of water consumed at the field level. This index increases with the increase in crop yield¡ reduction in water used¡ and both of the effects of these two factors together. The issues and sources of inefficiencies leading to the low values of WUE at the field scale could be various. The field scale is the domain which all of the agronomic practices¡ including land preparation¡ cultivation¡ crop treatments¡ and crop harvest occur in this environment. Moreover¡ the field is the place which all of the water management activities¡ from the source of water to the location of consumption¡ are all for this place. Therefore¡ the problems and issues of this water management scale directly and significantly affect on the extents of water use and the yield¡ which is the final goal of the producers. Considering interrelation and linkage of different scales¡ the issues of the field scale¡ causes higher scale problems¡ e.g.¡ environmental pollution¡ over exploitation of water resources¡ and socio-economic problems.Through facilitated brain storming meetings and harvest of the ideas of experts¡ resource persons¡ and the stakeholders from water management sector in general and the agricultural water in specific¡ the issues¡ problems¡ and challenges regarding improvement of WUE in the field scale in Iran were systematically and in a participatory way was identified. The experts were gathered and participated in the different brain storming meetings to identify the relevant problems¡ issues¡ and the challenges. The research outputs were mainly in the form of problem-tree. However some related measures and strategic executive and research pivots and objectives were also developed.Based on the results¡ the main sources of inefficiencies in field-scale WP (WUE) could be summarized in six main category as: 1) Low irrigation efficiencies¡ 2) Inadequate sources of reliable irrigation water resources¡ 3) Low quality of soil and water resources¡ 4) Low values of mechanization indices¡ 5) Problems associated with the irrigation systems¡ 6) Low levels of farmer’s knowledge and skills. From quantitative aspects¡ the number of problems in each of the six categories included 10.9¡ 9.3¡ 13.9¡ 39.5¡ 17.1¡ and 9.3 percent of the total problems respectively. From the strategic view points¡ the results of this research indicated that the issues and measures of improving WUE should not only followed in the water management sector but the agronomic issues and measures¡ especially agricultural mechanization¡ also play and important role in this aspect.