What is used to treat acid soils?

Lime calcium, often referred to simply as lime, is used to treat acid soils primarily because it helps to neutralize soil acidity. When applied to acidic soils, lime reacts with the hydrogen ions that contribute to acidity, increasing the pH level towards a more neutral range, which is beneficial for most crops. A proper pH range is essential for the availability of nutrients and overall soil health.

Adding lime not only makes the soil less acidic but also adds calcium, which is an important nutrient for plant growth. This amendment enhances the soil structure, promotes beneficial microbial activity, and can help reduce aluminum toxicity, which often becomes problematic in highly acidic soils.

The other choices, while beneficial in their own contexts, do not serve the primary purpose of addressing soil acidity in the same way that lime does. Potash, for instance, is primarily a source of potassium, gypsum provides calcium and sulfur but does not change soil acidity, and organic matter helps improve soil structure and fertility but does not directly neutralize acidity.