Radioactive Cesium in Soil

  Jun 09, 2020

Radioactive Cesium in Soil

Why is soil erosion worrisome?

Soil erosion, which involves disaggregation and displacement of soil, leads to decrease in its organic content and eventually its fertility. Soil supports plants, insects and microbial life and is formed by natural forces over a long period of time. If it is eroded, it can be disastrous in multiple ways: threat to food security and biodiversity; floods will worsen etc.

How does soil absorb carbon? 

Carbon reaches soil through the microbial action on withering plant parts and remains in soil, changing its physio-chemical properties and also enhancing its fertility. This way soil also sequesters carbon helping in regulating carbon levels in the atmosphere.

Why should soil erosion be monitored?

Natural and human activities are contributing to soil erosion and posing problems for food production and contributing to climate change. Therefore, monitoring of soil erosion induced-carbon loss from soil is important.

What breakthrough was made in India recently? 

Researchers at the ICAR-Indian Institute of Soil and Water Conservation, Dehradun have come up with a way to monitor the rate of soil erosion and associated decrease in organic content in soil by assessing levels of radioactive cesium in soil.

This method can help assess effectiveness of soil conservation strategies.

Why is it significant?

Radioactive cesium technology is a more rapid and less expensive method for soil erosion studies in the severely intensive croplands, it gives more accurate results for all types of erosion studies including historic, comparative and long-term soil and soil organic carbon erosion. Studies had shown that carbon concentration in soil correlates with levels of isotope of cesium in Doon valley of Northwestern Himalayas.

In all, samples were collected from 16 eroded sites apart from undisturbed land to study their physical and chemical properties. For measuring cesium levels in soil, gamma spectroscopy technique was used.

Different sites were found to have varying levels of cesium pointing at different degrees of soil degradation in different sites. By applying various formulas, the cesium loss was then used to calculate erosion and associated carbon loss in soil.