Working for Better Soil on Earth:
IAEA Celebrates Global Soil Week and the International Year of Soil
Soil, a living body and home for many microorganisms, plays an essential role in clean water and air, healthy agricultural crops, fruits and vegetables, productive grazing lands, diverse wildlife and forests, and even life-saving medicines. But we are losing this precious resource at increasing rates through land degradation and soil erosion. Soil degradation and erosion can lead to food insecurity, agricultural productivity decline, biodiversity loss and falling income, and ultimately to human migration and socio-political unrest. Every year soil erosion is estimated to lead to a loss of 10 million hectares of land worldwide, while some form of land degradation is affecting approximately 1.5 billion people, particularly in developing countries.
The international community is coming together today for Global Soil Week to emphasize the importance of land and soil and the role it plays in achieving the United Nations Sustainable Development Goals. This week, the IAEA is highlighting its work supporting Member States to address land and soil issues and is supporting the designation of 2015 as the United Nations International Year of Soil.
To the root of food
A quarter of the rapidly growing world’s population depends directly on food produced from land that is degrading. Soil erosion contributes to a loss of soil fertility, diminished crop productivity and deterioration of water quality. Degradation and erosion are further exacerbated by intensive farming, improper soil management associated with subsistence farming, deforestation, nutrient mining, as well as heavy rains and storms.
To meet the need for more food and to help protect soil and land, ‘climate smart’ agricultural practices must be developed to make soil more resilient against land degradation and the changing climate. The IAEA, in partnership with the Food and Agriculture Organization of the United Nations (FAO) through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, assists the Member States of IAEA in using nuclear techniques to combat land degradation and adopting smart agricultural practices.
Local scientists and farmers in over 60 countries have received technical support from IAEA enabling them to measure soil erosion. Nuclear techniques such as the measurement of existing radionuclides, Caesium-137 (137Cs), Beryllium-7 (7Be) and Lead (210Pb), help to precisely quantify soil erosion rates, and analysis with Compound Specific Stable Isotopes (CSSI) can identify erosion hot spots (more information can be found here). This can be followed up quickly with mitigation measures, such as terracing, contour cropping, use of minimum tillage, mulching, cover crops, and building of small stone walls and fences.
Replenishing soil to tackle greenhouse gas emissions
The emissions of nitrous oxide (N2O), carbon dioxide (CO2), methane (CH4) and ammonia from fossil fuels, deforestation and fertilizers used in agriculture have a profound impact on soil quality and crop production. Approximately 14% of the total greenhouse gas (GHG) emissions are from agriculture mainly due to the inefficient use of chemical fertilizers, improper use of farm effluent and manure, and overgrazing.
Nuclear techniques can help to find integrated solutions to reduce the GHG emissions associated with agriculture, while making soil more resilient to climate change. To counterbalance the increase of GHGs from carbon dioxide in agriculture, carbon sequestration is key: this is a process of changing agricultural practices to minimize emissions and to help remove CO2 from the atmosphere by replenishing the depleting carbon dioxide stores in degraded soil, which can boost soil productivity and its resilience to harsh climate conditions.
One method is to combine fertilizers together with plant growth regulators, as well as conservation practices in agriculture, which offers a cost-effective way to maximize outputs from crop production systems while increasing carbon sequestration in soils. Here, the use of stable isotope technologies offers the best choice for identifying sources of emissions and to help researchers and land users to determine appropriate mitigation options to optimize sequestration and to reduce emissions.
FAO and IAEA work together to help Member States to mitigate the effects of GHGs using nuclear and isotopic techniques. As there are different pathways and processes in soil for N to be converted to N2O, the use of nitrogen-15 isotopic technique allows the identification of the exact source of N2O production as well as N2, a non-greenhouse gas, so that different mitigation practices can be applied to minimize the emissions.
Changing climate, changing soil
The drought, floods and extreme weather events of climate change can cause more acidity in soils and increased salinization — an accumulation of water-soluble salt in soil — leading to soil erosion, desertification, reduced crop yields and, in turn, increased food insecurity. Acidic soil in particular mobilizes many toxic heavy metals, which can be taken up by plants and lead to its incorporation into human and animal food chains.
Soil acidity reduction can be achieved by applying lime, an additive made from pulverized limestone or chalk, to correct most pH problems and improve soil health. The IAEA has been assisting Member States in Africa, Asia, Europe and Latin America through the use of Nitrogen-15 and Carbon-13 isotopic techniques, to track carbon, water and nutrient movement and their dynamics to boost conservation practices in diverse agroecosystems.
Addressing global soil and land challenges relies on close coordination between farmers, workers and researchers, as well as partnerships between national, regional and international organizations. The IAEA works to provide support to its Member States and to further its joint efforts with other organizations.
Through these collaborations, important information and new capacities to use tools like isotope and nuclear techniques can more easily reach those who need it, which can help to ensure that agro-ecosystems are managed sustainably for agricultural purposes and for achieving conservation objectives.