Over 45 billion tons of soil is lost to erosion every year. Farmers and agricultural authorities in several countries have succeeded in slowing down erosion with the help of nuclear techniques.
All over the world, the Earth’s fine soil particles are losing ground to erosion. As 95 percent of food is cultivated in soil, the health and availability of Earth’s living surface impacts the quality and quantity of the food we produce. “Agricultural landscapes lose valuable soil mainly through soil redistribution processes,” said Emmanuel Chikwari, Head of the Chemistry and Soil Research Institute in Zimbabwe. “Once the soil resource is lost, it cannot be replaced for generations.”
To quantify the effectiveness of various soil conservation strategies, the Chemistry and Soil Research Institute in Zimbabwe launched a study utilizing caesium-137 (Cs-137) isotopes. In the 1950s and 1960s, Cs-137 radionuclides were released into the atmosphere by nuclear weapon tests and deposited in soils worldwide. By measuring Cs-137 concentrations, scientists could estimate soil erosion rates, specifically to compare the erosion of plots with and without tillage.
Soil erosion rates under conventional tillage reached 6.2 ton per hectare per year (t/ha/y), while rates were nearly 55 percent lower at no-tillage plots, at only 2.8 t/ha/y. “With the results of the study, we have the knowledge to improve our soil conservation efforts, and in turn, increase food security,” Chikwari said.
While wind and rain will always cause some erosion, this is amplified by improper agricultural practices, overgrazing, deforestation and climate change. Each year, approximately 45 billion tons of soil is displaced from agricultural use, and land is abandoned due to deteriorating productivity caused by erosion. The topic of this year’s World Soil Day is soil erosion — a process that nuclear techniques can help track and mitigate.
Healthy soils play an important role in achieving the United Nations Sustainable Development Goals — on hunger, clean water and the protection of the terrestrial environment. By applying nuclear techniques to measure and monitor the impact of land use and subsequently identify strategies to mitigate erosion, the IAEA, in cooperation with the Food and Agriculture Organization of the United Nations (FAO), is working to help conserve this vital resource.