Effect of Fly Ash on Release Behaviour of Potassium In Soils of Arid Region

Effect of fly ash on release behaviour of exchangeatle (IN NH₄Ac-K) and nonexchangeable (boiling IN HNO₃-K) K⁺ were studied in laboratory in a sandy and a loamy soils by mixing fly ash at 0, 25, 50. 75 and 100% (w/w). A major portion (68 to 76%) of exchangeable K⁺ (NH₄Ac-K) was extracted in first extraction in sandy soil. The subsequent extractions decreased the K⁺ release. In loamy soil, only 38 to 42% of exchangeable K⁺ was released in the first extraction. The magnitude of K⁺ release was slower in loamy soil than the sandy soil. The release of nonexchangeable K⁺ was almost similar in both the soils in first extraction. Addition/mixing of successive levels of fly ash had little effect on the release pattern of K⁺ in these soils.