How can alkaline soils be reclaimed?

Alkaline soils, also called sodic soils or high pH soils, are common in many parts of India, especially in dry and irrigated regions. These soils contain excessive sodium, which affects soil structure, reduces water movement, and makes nutrients less available to plants. As a result, crops show poor growth, yellowing, stunted roots, and low yields. Reclaiming alkaline soils is important for improving fertility and making them suitable for farming. With proper management, even highly alkaline soils can be restored and used for successful crop cultivation.
One of the most effective ways to reclaim alkaline soils is by applying gypsum. Gypsum contains calcium, which replaces the excess sodium in the soil. This helps improve soil structure, makes the soil more crumbly, and allows better water movement. Farmers generally apply gypsum based on soil test results, but a common recommendation is 1–2 tonnes per hectare for moderately alkaline soils. Gypsum should be applied and mixed well into the topsoil, followed by irrigation to help it dissolve and move into the root zone.
Adding organic matter is another very important step. Organic manure, compost, green manure, and crop residues help improve soil physical structure. They reduce the impact of sodium, increase soil microbial activity, and improve nutrient availability. Well-decomposed farmyard manure added at 8–10 tonnes per hectare every season gradually improves soil health. Growing green manure crops like dhaincha or sunhemp and ploughing them into the soil is also highly beneficial. Over time, organic matter helps lower soil pH and increases soil fertility.
Proper irrigation management also plays a major role in reclaiming alkaline soils. Many alkaline soils develop due to poor-quality irrigation water or continuous flooding. To improve these soils, farmers should use good-quality water when available and avoid over-irrigation. Light and frequent irrigation helps wash excess sodium downward. Installing proper drainage systems is important in areas where water stagnation occurs, as standing water increases alkalinity and creates hard soil crusts.
Using acid-forming fertilizers such as ammonium sulphate or single super phosphate can help reduce soil pH slowly over time. These fertilizers release mild acids into the soil when they dissolve, which helps neutralize alkalinity. They also supply essential nutrients like nitrogen, phosphorus, and sulphur, improving plant growth. However, they should be used based on soil testing results to avoid nutrient imbalance.
Growing salt-tolerant crops is another practical approach during the recovery period. Crops like barley, mustard, wheat, sorghum, and some grasses tolerate alkaline conditions better than many other crops. Growing such crops for a few years improves soil structure and reduces the negative effects of sodium. Once the soil improves, farmers can shift to more sensitive crops.
Mulching is also helpful because it reduces evaporation, prevents salt accumulation on the soil surface, and improves moisture retention. Straw, crop residues, or plastic mulch can all be used effectively.
In short, alkaline soils can be reclaimed through gypsum application, adding organic manure, improving irrigation and drainage, using acid-forming fertilizers, and growing salt-tolerant crops. These steps gradually reduce soil alkalinity, improve fertility, and restore the soil for productive farming. By following these practices consistently, farmers can convert unproductive sodic soils into healthy, fertile fields with better crop yields.