Question

1. When lime is added to an acid soil, explain what it does to 1) soil pH (and what is the mechanism by which it changes the pH); 2) cation exchange capacity (Hint: Think back to pH-dependent charge to understand the effect on cation exchange capacity.) and; 3) the composition of exchangeable cations.

2. Why do some soils need more lime to raise their pH than other soils? Explain your answer in terms of buffering capacity, and active vs. reserve acidity.

3. What is the key difference between saline-sodic and sodic soils, and which type of soil would be the most problematic in terms of trying to grow plants?

Answer 1