Nguyễn Xuân Cự (trang 20-24)
Từ khoá: chuyển hoá, cố định, photpho, đất
Summary
Phosphorus fixation and transformation in some soil types of Vietnam
Most of studied soils have high P fixation capacity, which is decreasing from ferralit acrisols to xanthic ferrasols, gleyic fluvisols, eutric fluvisols and haplic arenosols. The fraction of Fe-P is predominant in most of studied soils, except xanthic ferralsols. Fraction of Al-P is higher than Ca-P I soil with highly ferralitization intensity in rhodic ferrasols, nut lower in soils with weakly ferralitization intensity in eutric fluvisols and haplic arenosols. Water logged has high effects on P fraction in soils. Contents of org-P, Ca-P and Al-P decreased but the contents of Fe-P increase due to logging, P applied also has significant effect on the sorption capacity as well as the fractions of P in soils. At high rates of P applied, all the fraction of P increases significantly, especially Fe-P and Ca-P