Nuclear techniques to slow soil erosion

Soil degradation affects 1.9 billion hectares of land worldwide, about two-thirds of the world's soil resources.

Soil erosion is the single largest contributor to land degradation, resulting in the loss of 75 billion tonnes of fertile soil per year, at an annual economic cost of some 126 billion US dollars.

Erosion affects the top, most fertile layer of soil and carries away much of the fertiliser used in agriculture, depositing it in freshwaters where it feeds algae, drastically reducing water quality.

Nuclear techniques can determine the exact cause and origin of soil erosion, the most common of which include radionuclides from radioactive fallout, which helps to assess soil erosion rates, and stable isotope analysis by compound, which helps to detect degradation hotspots.

Radionuclides from fallout can help to detect variations in soil redistribution patterns and rates over large catchment areas and to assess the efficiency of soil conservation measures to control soil erosion. They can be measured non-destructively and relatively easily using modern high-resolution gamma spectrometry.

The compound stable isotope technique makes it possible to determine where the eroded soil originated, as compound stable isotopes are specific to different plants. The study of their composition makes it possible to trace their origin.

The combination of the two methods makes it possible to establish a strong link between the sediment in the catchment area and the origin of the erosion.