Introduction
According to ISRO's Desertification and Land Degradation Atlas (2021), approximately 29.77% (97.85 million hectares) of India's Total Geographical Area (TGA) is undergoing land degradation. This progressive decline in soil quality and arable area poses a critical challenge to national food security, biodiversity, and long-term eco-agricultural sustainability.
Geographical Processes Responsible for Soil Degradation
Soil degradation across India manifests through diverse physiographic, climatic, and anthropogenic drivers:
- Water Erosion: Intense monsoon downpours combined with deforestation and steep slopes cause sheet, rill, and gully erosion. This is particularly acute in the Shiwalik foothills, the Chambal ravines, and the Western Ghats, stripping the nutrient-rich topsoil.
- Wind Erosion: Prevalent in arid and semi-arid tracts, wind erosion accounts for approximately 5.5% of the total geographic area. Strong seasonal winds displace loose, desiccated surface soil particles across western Rajasthan, northern Gujarat, and parts of Haryana.
- Salinization and Waterlogging: In the canal-irrigated commands of north-western India (such as Punjab and Haryana), unscientific flood irrigation paired with poor subsurface drainage induces high water tables. Capillary action subsequently draws dissolved mineral salts to the surface, creating barren saline-alkaline soils (reh or kallar).
- Chemical and Nutrient Depletion: Prolonged monocropping, distorted NPK fertilizer application ratios, and burning of crop residues severely deplete Soil Organic Carbon (SOC) and impair soil microbial diversity.
- Vegetation Degradation: Overgrazing in semi-arid rangelands and clear-felling of forest tracts diminish natural ground cover, leaving soils unprotected against thermal stress and raindrop impact.
Suitable Remedial Measures and Policy Interventions
Addressing soil degradation requires a combination of structural, biological, and policy-driven agronomic approaches:
- Chemical Soil Amendment: Amending alkaline soils with gypsum and treating acidic soils with lime or dolomite, strictly guided by localized testing under the Soil Health Card (SHC) scheme.
- Mechanical and Bio-Engineering Interventions: Constructing shelterbelts and windbreaks using drought-tolerant vegetation in arid zones; employing contour bunding, trenching, and bench terracing across hilly slopes to retard surface runoff.
- Hydrological Management: Adopting a decentralized 'ridge-to-valley' conservation approach through check dams, percolation tanks, and rainwater harvesting under the Watershed Development component of Pradhan Mantri Krishi Sinchayee Yojana (PMKSY).
- Agronomic and Conservation Agriculture: Promoting zero-tillage, residue mulching, intercropping with legumes, and crop rotation via the National Mission for Sustainable Agriculture (NMSA).
- Organic and Regenerative Practices: Incentivizing organic manures, bio-fertilizers, and green manuring through Paramparagat Krishi Vikas Yojana (PKVY) to rebuild Soil Organic Carbon levels.
Conclusion
Transitioning from resource-intensive agricultural practices to precision, climate-resilient farming is imperative. Sustained land restoration will enable India to meet its United Nations Convention to Combat Desertification (UNCCD) target of restoring 26 million hectares of degraded land by 2030 and fulfilling Sustainable Development Goal 15.3 on Land Degradation Neutrality.