The agriculture is the use of water implies increased demand worldwide. The farmland irrigation involves the use of 70% of water resources in the world. In developing countries, often the water used for irrigation accounts for 95% of total water use, and plays an essential role in the production and food safety. In the long term, the development and improvement of agricultural strategies for these countries is conditioned to the maintenance, improvement and expansion of irrigated agriculture.
Moreover, the increased pressure on water resources for agriculture competes with the use of water for other purposes and represents a threat to the environment and unsustainable use of water resources of the planet. Water is a resource that can create tensions and conflicts between countries that share this resource through its rivers located in the areas of primary or intermediate parts along the river (Hoekstra & Chapagain, 2007). The irrigation water is one of the biggest competition uses relative to other sectors, and accounts for 70-90% of water use in certain regions.
The water used for agricultural purposes represents 30% of the resources extracted. This of course varies according to climate, crop type and agricultural methods or techniques. For example, the role of irrigation systems is essential in the South that depends on irrigation to maintain agricultural production, compared with the countries of Central and West European (increased rainfall and therefore less reliance on systems irrigated).
In fact most of the irrigation water in Europe is for the southern European countries like Spain, Italy, France, Greece and Portugal with 85% of the total irrigated areas in the EU. On the other hand, in United States irrigated agriculture accounts for 56% of agricultural production and occupies the order of 18% of the total agricultural area (Howell, 2001).
Water Resources for Irrigation
The water used for irrigation comes from natural sources and alternatives. Natural sources include rainwater and surface runoff (lakes and rivers). These resources should be used in a responsible and sustainable manner. The amount of water that comes from rain water depends on atmospheric conditions of the area. Surface water is a limited resource, and usually requires the construction of reservoirs and dams for operation with significant environmental impact.
Sources alternatives are irrigated reuse of municipal water and drainage water. In any case the use of recycled water can have adverse effects on public health and the environment. This depends on the application/use made ??of this recycled water, soil characteristics and limitations, weather conditions and agricultural practices (Shafroth, et. al., 2005). Therefore, it is imperative that all these factors are taken into account in the management of water recycled. Then study this in greater detail.
Water Reuse for Irrigation
The use of recycled water for irrigation is a common practice. In Europe, for example, there is a major project in the area of Clermont-Ferrand, France since 1997 with recycled water irrigated an area of 700ha of maize. In Italy there are over 4000 also has a number of crops that use recycled water for irrigation. In United States there are several similar projects. The quality of water used for irrigation is crucial for the production and quality in agriculture, maintaining the productivity of soil in a sustainable and ...