The aim of this paper is to provide policy-makers with a helpful overview of the technical and economic aspects of water use in agriculture, with particular emphasis on crop and livestock production. Through 2050, in many countries, agriculture will remain an important determinant of economic growth, poverty reduction, and food security, even as, over time, the proportion of agricultural revenue in national gross income declines. Water use in agriculture will remain substantial, irrigated areas will expand and competition for water will increase in all sectors. Most likely, overall supplies of land and water will be sufficient to achieve global food production goals in 2050; although poverty and food insecurity will remain pressing challenges in several regions and countries. Thus, the focus of this report is on the regional and national aspects of food security.

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p. 213-255 | Food security and water security in the Mediterranean are intrinsically linked and are facing similar challenges. Food security is threatened mainly by the high dependency of Mediterranean countries on food imports, making them vulnerable to external pressures such as volatile food prices. From a nutritional standpoint, the number of overweight and obese people has increased as a result of the traditional Mediterranean diet being abandoned. Water security has degenerated due to the deterioration of internal freshwater resources, both in terms of water quantity and quality, with a high dependency on external water resources, higher regional water footprints than the global average, increasing scarcity of renewable water resources, an increased number and capacity of dams exerting pressure on freshwater ecosystems, and a growing risk of conflicts between water users and countries. Access to water and sanitation remains a major challenge in the region. Territorial divisions separating coastal urban and remote rural areas are growing stronger, making isolated populations such as smallholder farmers particularly at risk of food and water insecurity. With climate change, precipitation is expected to decrease and temperatures to rise in the region, which will affect water supply (and thereby energy and food supply). It will also directly affect soil moisture and crop growth, thereby further increasing irrigation water needs. There are clear but difficult to measure interactions between the water, energy and agricultural sectors, as they are all interdependent, which calls for integrated policies and management. Agriculture being the largest water user in the region, further efforts need to be made to promote the use of non-conventional water resources. The conservation and restoration of Mediterranean agroecosystems is key to ensuring sustainable development. This requires better management of continuing arable land loss, land use intensification, and soil erosion and salinization. Integrated Water Resources Management and Water Demand Management (WDM) provide guidelines for achieving better water efficiency and reducing conflicts between users.

Seventy-one percent of the earth surfaces is covered by oceans. Water therefore is an important habitat for microorganisms and the other living beings. A consistent microbial biodiversity is present in water from phototrophs to chemioorganotrophs. The complex relationships between different microorganisms and the environment are often modified by organic, chemical and physic contaminations. The input of organic material can determine pathogenic pollution. The presence of pathogens has to be monitored to eliminate serious problems for animal and human health. Water, in fact, can be a vehicle direct (drinking water) or indirect (irrigation water) for microbial pathogens | Il 71% della superficie terrestre è costituito dagli oceani. L'acqua pertanto è un importante ambiente per i microrganismi, oltre che per tutti gli altri esseri viventi. Una grande varietà di tipi microbici colonizzano l'habitat acquatico, dai fototrofi ai chemiorganotrofi. Le dinamiche che si creano fra i diversi componenti microbici e l'ambiente sono spesso alterate da contaminazioni organiche, chimiche e fisiche. L'immissione di materiale organico può anche essere fonte di inquinamento di microrganismi patogeni la cui presenza va monitorata al fine di evitare seri problemi alla salute umana e animale. L'acqua, infatti, può rappresentare un veicolo di trasferimento, sia diretto (acqua potabile), sia indiretto (acque di irrigazione), di microrganismi patogeni

PR | IFPRI3; ISI; CRP5 | EPTD | CGIAR Research Program on Water, Land and Ecosystems (WLE)

Water resources are already very scarce. With further demand from population growth, dietary changes, biofuel production, urbanisation and climate change, it will be extremely difficult to find enough supply to enable an increase in global food production by 70 per cent. There are, however, potential solutions that involve increasing water productivity, improved water storage, more irrigation and re-using waste water. But current investment levels in overseas development aid and spending at country level are unlikely to be sufficient to ensure food security in the relatively short- term, let alone by 2050, when the global population is forecast to be nine billion. This article describes some of the issues that have to be faced to deliver food security and overcome water scarcity, and how these improvements can be achieved through a combination of science, policy and investment.