Africa Water, Sanitation & Hygiene September 2018 Vol.13 No.4 | Page 4

Guest Editorial
Water in Agriculture
Water use in agriculture is at the core of any discussion of water and food security.
Agriculture accounts for, on average, 70 percent of all water withdrawals globally,
and an even higher share of “consumptive water use” due to the evapotranspiration
requirements of crops. Worldwide, over 330 million hectares are equipped for
irrigation. Irrigated agriculture represents 20 percent of the total cultivated land,
but contributes 40 percent of the total food produced worldwide.
Competition for water resources is expected to increase in the future, with particular
pressure on agriculture. Significant shifts of inter-sectoral water allocations will be
required to support continued economic growth. Due to population growth,
urbanization, industrialization, and climate change, improved water use efficiency
will need to be matched by reallocation of as much as 25 to 40% of water in water
stressed regions, from lower to higher productivity and employment activities.
In most cases, this reallocation is expected to come from agriculture, due to its
high share of water use. 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 as well as conveyance of water
‘sales’, mainly from 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 localitie