MỘT SỐ DẠNG KALI CỦA ĐẤT PHÙ SA SÔNG HỒNG VÀ KHẢ NĂNG CỐ ĐỊNH KALI CỦA ĐẤT

Nguyễn Hữu Thành, Cao Việt Hà¹

¹Đại học Nông nghiệp I

Từ khoá:  kali, đất phù sa, sông Hồng, cố định kali

Summary

Some forms of potassium of fluvisols in Red River Delta and soil potassium fixation capability

Some K forms and K fixation of 30 soil samples were determined, collected from surface (0-20cm) and subsurface (20-40cm) horizons in 15 profiles of Red River alluvial soil in Gia Lam, Ha Noi. The content of available K in soils was small. Water soluble K was 0.44-1.54mg/100g soil and exchangeable K was 4.07-11.09mg/100g soil in surface horizons. Whereas the content of the total and nonexchangeable K was rather high, it was 1.54-2.56% and 32.6-64-67mg/100g soil in surface horizons, respectively. Most of soil samples had a high K fixation, fixed K ratio of these samples was >37.3% when K concentration of 0.11cmol(+)/l added to the soils. This ratio was decreased when increasing of the K concentration added to the soils.