A study has uncovered alarming insights into India's soil health, indicating significant erosion across the country. The research, titled "Geospatial modelling and mapping of soil erosion in India," brings to light that nearly 30% of India's landmass is undergoing "minor" soil erosion, while a critical 3% is grappling with "catastrophic" topsoil loss.

Topsoil, the crucial upper layer of soil essential for agriculture due to its nutrient and moisture retention capabilities, is under threat from erosion. This erosion not only reduces soil fertility but also leads to diminished crop yields, impacting agricultural sustainability.

Manabendra Saharia, assistant professor of civil engineering at the Indian Institute of Technology Delhi and one of the study's authors, emphasised the need to classify soil erosion levels comprehensively, especially considering India lacked such a classification system previously. The study, which introduced six classifications ranging from "minor" to "catastrophic" based on soil erosion metrics, sheds light on the severity of soil degradation.

The study identifies the Brahmaputra Valley in Assam as a significant hotspot for soil erosion, with Assam alone losing nearly 300 square kilometres or 31% of its topsoil to "catastrophic" erosion. This loss is particularly concerning given that soil formation is a slow process, with the Food and Agriculture Organization of the United Nations noting it could take up to 1,000 years to produce a few centimetres of topsoil.

Aside from the Brahmaputra Valley, regions like the lower Himalayan reaches and Odisha also face critical erosion challenges due to factors like loose soil, unstable slopes, seismic activity, and anthropogenic interventions such as deforestation and intensive farming practices.

The study's use of the Revised Universal Soil Loss Equation (RUSLE) enabled a detailed analysis of potential soil loss across India, incorporating factors like predicted crop loss, rainfall, soil erodibility, slope steepness, and management practices. This holistic approach provides valuable data for future soil conservation planning and emphasises the urgent need for sustainable land management practices to mitigate soil erosion and preserve agricultural productivity.