Water Availability and Management for Food Security.

Food security is directly linked to water security for food production. Water availability for crop production will be dependent upon precipitation or irrigation, soil water holding capacity, and crop water demand. The linkages among these components in rainfed agricultural systems shows the impact of a variable precipitation regime among years, the increasing crop water use rates due to climate change, and variable soil water holding capacity within a field. In rainfed environments, water management strategies focused on increasing water storage in the soil profile and reducing soil water evaporation rates provide for increased crop productivity and reduced variation in production among years. In temperate regions, the shift in seasonality of precipitation to a reduced and more variable summer rainfall pattern increases the positive impact of water management on food security. Irrigated environments are often considered as being more resilient to variations in environmental conditions because of the ability to supply water to meet atmospheric demand; however, there are two aspects which need greater attention. First is management practices that improve irrigation efficiency to enhance food production per unit of water applied. Second is the improved understanding of how climate and soil interact to determine the need for irrigation and how supplemental irrigation could offset the impacts of short-term water stress at critical growth stages. If we assume that food production is a direct function of water availability then food security will also depend upon water availability. Management of agricultural systems to provide food security will require increased attention to the soil resource in both irrigated and rainfed environments because both result in increased quantity and quality of food production to ensure food security.  Management of our agricultural systems for food security will place a greater emphasis on the management of our soil and water resources.