Nguyễn Hữu Thành (trang 19-27)
Từ khoá: khoáng vật, sét, cố định, kali, fluvisol
Cailay mineral composition and potassium fixation in some soil units under fluvisols soil group in Vietnam
Clay mineralogical composition and fixation of potassium was determined in some fluvisols. Mica was a predominant mineral. Chloride and kaolinite with lesser amount. Minor amounts of smectite and vermiculite were detected in one pedon of the Red river plain. 2 kinds of mixed-layer minerals were identified. The amount of K fixed was determined. The magnitude of the K fixation rate varied widely among the soils. Highest K fixation rate 76.9% was observed in the subsoil of eutric fluvisols of Red river plain. Dystric fluvisols of Thaibinh river plain had medium K fixation. The lowest K fixation rate 20.7% was detected in thionic fluvisols.