Water is a critical input for agricultural production and plays an important role in food security. Irrigated agriculture represents 20 percent of the total cultivated land and contributes 40 percent of the total food produced worldwide. Irrigated agriculture is, on average, at least twice as productive per unit of land as rainfed agriculture, thereby allowing for more production intensification and crop diversification.
Due to population growth, urbanization, and climate change, competition for water resources is expected to increase, with a particular impact on agriculture. Population is expected to increase to over 10 billion by 2050, and whether urban or rural, this population will need food and fibre to meet its basic needs. Combined with the increased consumption of calories and more complex foods, which accompanies income growth in the developing world, it is estimated that agricultural production will need to expand by approximately 70% by 2050.
However, future demand on water by all sectors will require as much as 25 to 40% of water to be re-allocated from lower to higher productivity and employment activities, particularly in water stressed regions. In most cases, such reallocation is expected to come from agriculture due to its high share of water use. Currently, agriculture accounts (on average) for 70 percent of all freshwater withdrawals globally (and an even higher share of “consumptive water use” due to the evapotranspiration of crops).
The movement of water will need to be both physical and virtual. Physical movement of water can occur through changes in initial allocations of surface and groundwater resources mainly from the agricultural to urban, environmental, and industrial users. Water can also move virtually as the production of water intensive food, goods, and services is concentrated in water abundant localities and is traded to water scarce localities.
Inter-sectoral water re-allocations and significant shifts of water away from agriculture will also need to be accompanied by improvements in water use efficiency and improvements in water delivery systems. Improving the efficiency of water use in agriculture will also depend on matching of improvements main system (off-farm) with appropriate incentives for on-farm investments aiming to improve soil and water management. Such options will require improved water delivery systems to provide adequate on-demand service as well as use of advanced technologies (i.e., soil moisture sensors and satellite evapotranspiration measurements) to improve efficiency and productivity of water in agriculture.The full article is for subscribed members only. To view the full article please subscribe. It’s FREE!Log In Register
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