Acid Soils of India

Understanding spatial distribution of acid soils in the country is important for their effective management, ensuring sustainable crop production and informed policy decisions. The present assessment revealed that about 31 % area (approximately 98.71 mha) of the country has soil pH ≤ 6.50. In the last 13 years, area with strongly acidic soils decreased from 6.24 to 0.61 mha and area with moderate soil acidity increased from 24.41 to 36.25 mha in India. Integrating soil acidity information into policy and practice will enable more efficient, evidence-based decision-making and support sustainable agricultural development. State governments could use spatial maps of soil acidity to identify and prioritize high-risk areas for intervention. 

Focused application of lime and other ameliorants can improve soil fertility and optimize the use of public resources. Soil acidity data could guide site-specific fertilizer recommendations. Addressing nutrient deficiencies (e.g., phosphorus, molybdenum) and toxicities (e.g., aluminium, iron, manganese) will support balanced fertilization and enhance crop productivity. Policies should promote the adoption of acid-tolerant crop varieties and cropping systems suited to local soil pH conditions, thereby improving resilience and farm incomes in affected regions. The data could be used by the state agricultural departments to develop locationspecific management practices. This includes determining the correct type and amount of amendments needed for different soil types and acidity levels. Soil survey data, including acidity levels, is a crucial input for state planners and stakeholders in preparing strategic sustainable land use plans, watershed development programmes and managing natural resources. Information on acid soil areas could be used in preventing further land degradation and associated environmental issues, such as the leaching of toxic metals (like aluminium) into groundwater, by guiding appropriate management and conservation measures. Research institutions should leverage soil acidity data to develop site-specific technologies, including improved soil conditioners and crop varieties. Strengthened extension systems are essential to ensure effective field-level adoption.