Note: in the target, the (x) % is not specified as such a value will vary between countries and is recommended to be defined at country level instead.
The world is facing a progressive condition of scarcity of water and land resources that is threatening the ability of key agricultural systems to provide global food security. Freshwater resources are limited and the amount of arable land available for agriculture is decreasing. Demand for food is increasing from a fast-growing, wealthier and increasingly urbanized population, and cities are exerting pressure to re-allocate water from agriculture to urban needs.
Increased water productivity in agriculture is imperative to meeting global food needs and agricultural sustainability. Agriculture uses approximately 70% of total water withdrawals worldwide. Irrigated systems are 18% of the cropped area but they produce 40% of the food supply. However, the majority of large-scale irrigation systems are performing well below their potential. The world will not achieve food security without significant increases in the amount of irrigated land and in water use efficiency. Accordingly, to enhance the productivity of irrigated agriculture, a coherent strategy and plan to optimize irrigation technology and management is needed.
To meet the requirements of this target, global freshwater productivity will have to be increased. Water Productivity (WP) is defined as the ratio of net benefits from crop, forestry, fishery, livestock and mixed agricultural systems to the amount of water used to produce those benefits. More specifically, physical water productivity is defined as the ratio of agricultural output to the amount of water consumed. The efforts under this target will focus on the opportunities for improving physical water productivity, especially in areas of low productivity.
Measures to improve physical water productivity may include:
- enhanced operation and maintenance of irrigation systems;
- on-farm water management to minimize non-productive consumption of water;
- use of improved crop varieties;
- use of improved cropping systems and agronomics, such as conservation tillage;
- design and construction of upgraded or new irrigation water delivery systems;
- employment of improved or advanced irrigation systems;
- development of financial frameworks to provide incentives for the adoption of best practices and new technology;
- use of low quality water in non-conventional (not for direct human consumption) applications such as forestry;
- aquifer characterization to determine quantity and quality of available ground water;
- evaluation of surface water supplies to determine quantity and quality available for agriculture use.
Increased water use efficiency in irrigation through improved technologies and management practices is the path to the solution for improving water productivity in large-scale irrigation
The main stakeholders in the improvement of physical water productivity will include farmers,
landowners, irrigation districts/agencies, local governments, regional/state governments and
federal governments. Costs will necessarily increase for the farmers, but will be offset by increased yields, and thus greater total revenues.
Individual countries will have to assess their needs and develop strategies that are economically and technologically feasible given the constraints of the locality.
Consideration also will need to be given to the social, cultural and environmental issues surrounding water use in the locality. Individual countries will need to develop measurement tools to assess the progress toward the target. Once these tools have been developed, they can be used to determine the appropriate percentage increase as compared to the 2005 – 2007 baseline. Then, comparisons based on yield per m3, per ha and per year can be made for specific crop categories.