Agriculture consumes, on average, 70% of the total freshwater used around the world, mainly through irrigation for food production. However, less than half of this water is being used efficiently; the rest is wasted through evaporation and deep drainage and runoff. This water – whether from rainfall or irrigation – carries nutrients, pesticides and chemicals to ground and surface water resources, harming water quality and habitat, said Heng.
Isotopic and nuclear techniques are contributing to better soil and irrigation management by improving water use practices and efficiency. These techniques are becoming an integral part of agricultural water management, as isotopes (oxygen-18 and deuterium) can help determine the origin and movement of water in plants and soils (see The Science box). For instance, scientists can measure with isotopes how much water is used and “transpired” by a plant or is evaporated from the soil.
With such information, strategies can be developed to improve crop production, reduce water losses and prevent land, water and ecosystem degradation.
In Africa, which suffers from severe drought in some areas, the IAEA has run several technical cooperation projects on adaptation to climate change using drip irrigation. In Sudan for example, scientists were successfully trained to use the minimal amount of water and fertilizer crops need to flourish, and in turn they supported 1050 small scale women farmers – among them many refugees from neighbouring countries – improve subsistence agriculture production. They succeeded turning dry lands into vegetable fields that feed families and entire villages, contributing to poverty alleviation and local food security enhancement in rural areas.
In Mauritania, 400 rural women, family farmers, living in a hostile desertic environment – with water scarcity, high temperatures and sandy soils – have benefited from the support of scientists trained by the IAEA. They increased yield and varieties of vegetables grown in the desert and grew their income for improving education and health.