Irrigated agriculture occupies 17% of the globally cultivated area, but provides 40% of global biomass production in agriculture (food, feed and fibre). However, water use efficiency in irrigated agriculture is typically low. Increasing human population, increased energy crop production and an increase in water demand from domestic, industrial and environmental sectors have resulted in an urgent need for improved water use efficiency in irrigated agriculture. There are several options for increasing water use efficiency, including the breeding of drought-tolerant cultivars, growing more water demanding crops in wetter regions, and ceasing irrigation on unsuitable land.
Improved water use efficiency can be achieved through:
i. Efficient irrigation methods such as sprinkler, surface drip, and subsurface drip irrigation. While they reduce labour requirements through automation, they require substantial investments and management skill, and are costly to operate.
ii. Innovative irrigation scheduling systems that fine-tune water volumes and dates of irrigation (Allen et al., 1998). This can be achieved through the use of sensors that measure soil water content in the root zone, satellite data, and measuring plant water status.
iii. Site-specific application of water, i.e. applying different amounts of water to different parts of the field, depending on local soil and crop conditions; it increases water use efficiency and reduces leaching.
Innovative water management can be coupled with innovative fertiliser and pesticide management, using water to transport nutrients and active ingredients for pest and disease control. Managed deficit irrigation can also conserve water in irrigated agriculture.
Valerie theme leader: Arianna Facchi