اليوم العالمي للتربة : دور التقنيات النووية في وقف ملوحة التربة ودعم التعافي.

In partnership with the Food and Agriculture Organization of the United Nations (FAO), the IAEA applies various isotopic techniques to determine water and nutrient use efficiency and enhance soil fertility and productivity for climate-smart agriculture, including in very dry climates.

These techniques include the fallout radionuclides technique, which is used to help determine the rate of soil erosion and the effectiveness of soil conservation practices; the development of small scale irrigation techniques known as drip irrigation; and the use of the soil moisture neutron probe in dry climates to determine the moisture level in the soil and to decide when and how much water to add.

These nuclear techniques have been implemented in many countries in Africa, Asia and the Pacific, and Latin America, through the IAEA technical cooperation programme supporting the adoption of climate-smart agricultural techniques in Mali, Mauritania, Nigeria, Sudan (drip irrigation) and Chile, Morocco, Sri Lanka, Tunisia, Uganda, Viet Nam (soil erosion).

“According to the UN, approximately 20% of the Earth’s vegetated surface is either highly degraded or undergoing high rates of degradation, with 12 million hectares of land lost each year to degradation processes,” said Lee Kheng Heng, Head of the Soil and Water Management and Crop Nutrition Section at the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture. “Poverty-related agricultural practices are a major contributor to desertification in Africa. Continuous cultivation without adding adequate fertilizers, overgrazing, lack of soil and water conservation practices, and indiscriminate bushfires aggravate the process of desertification. Isotopic techniques can identify the causes to provide information to overcome these problems,” she added.

Some of the ongoing initiatives make use of modern communication technology. For instance, in Kenya, the use of mobile phone technology has enabled farmers to know when to irrigate and apply fertiliser, based on data transmitted to them from weather stations installed with the support of the IAEA, through its technical cooperation programme.

The sustainable use of groundwater can support life and agriculture in arid areas, enabling people to improve their livelihoods even when rain is scarce.

Honduras lies in the so-called Central American Dry Corridor, a region on the Pacific Coast of Central America that is among the most sensitive areas to climate change worldwide, according to Ricardo Sánchez-Murillo, Associate Professor at the School of Chemistry at Costa Rica’s Universidad Nacional Heredia. This is characterized by alteration between long periods of drought and extreme rainfall events, which makes these areas less habitable, causing many to leave their homes and migrate.

Deforestation is compounding the problem, said Sánchez-Murillo. “Once you have watersheds devastated by deforestation, you have a precipitation deficit; you don’t have seasonal water storage. Therefore, you don’t have a lot of surface water discharge or groundwater recharge, so wells can go dry.”

Solving the issue of drought with the help of nuclear techniques is one of the top priorities of the technical cooperation programme of Honduras with the IAEA. Around 40% of the Honduran territory is affected by land degradation. Therefore, sustainable land and water resource management is key to the sustainable development of the country, said Tania Peña Paz, Coordinator of the Master’s Program of Hydrological Resources at the National Autonomous University of Honduras, who uses isotopic techniques to study groundwater and determine its age and rate at which it recharges from rain. “The earlier we start with sustainable land management, the earlier we will achieve results,” she said. “The information is key for recovering degraded areas, as well as conserving those that have not yet been affected.”

The IAEA’s support is focused on helping Honduras use isotopic techniques to analyse data from water samples to understand from where exactly the water is being recharged and at what rate. This has enabled them to create an inventory of water sources.

Growing populations and expanding industries require more water. In arid climates subject to desertification, cities such as the Honduran capital Tegucigalpa are threatened by a shortage of water. Honduran experts sought the IAEA’s assistance to determine the suitability of aquifers as a quick and economical solution to improve the availability of drinking water in Tegucigalpa.

With the support of IAEA experts, they created a network of monitoring wells around the city and analysed the groundwater samples collected to determine which areas are critical for ecosystem protection and restoration. As a result of this joint work, local experts recommended setting up a water governance body of local stakeholders to prevent water disputes, as well as reforestation and the development of a strong environmental curriculum in schools to increase awareness and reduce water pollution.

The IAEA is supporting similar initiatives in several neighbouring countries, where it is building national capacity in evaluating groundwater resources, supporting sustainable groundwater management.

“For the community, the impact is very important because we are talking about the conservation of water resources and the sustainable use of our natural resources,” said Peña Paz.