Economic and agronomic impacts of soil acidity in rainfed agriculture: Reclamation strategies for the north eastern hill region of India

Soil acidity poses a significant challenge to rainfed agriculture in the North Eastern Hill (NEH) region of India, where approximately 80% of the soils are classified as acidic (pH < 6.0). The study evaluates the impact of soil acidity on crop productivity and estimates the economic losses incurred due to untreated acidic soils. A total of 2,000 thousand hectares of cultivated land in the NEH region requires soil amelioration, with Meghalaya (610.24 thousand ha) and Nagaland (418.07 thousand ha) having the highest reclamation needs. Maize, pulses, and oilseeds are the most affected crops, with a projected production increase of 15–25% upon reclamation. Economic losses due to soil acidity are substantial, ranging from ₹92.4–153.9 crore for pulses, ₹87.2–145.3 crore for oilseeds, and ₹102.1–170.2 crore for maize annually. The study highlights liming as the primary reclamation strategy, with an estimated cost of ₹8.00 crore for pulses, ₹4.33 crore for oilseeds, and ₹5.42 crore for maize at an application rate of 200–400 kg/ha. Alternative amendments, such as poultry manure (2.5–5 t/ha) and lime sludge (400–500 kg/ha), have been identified as cost-effective substitutes. The findings underscore the urgent need for targeted interventions, including financial support, policy-driven soil reclamation efforts, and awareness programs, to ensure sustainable agricultural productivity in the NEH region.