Nguyễn Thế Hùng, J. Schoenau (trang 14-18, 24)
Từ khoá: ảnh hưởng, bón phân, đạm, sắn, độ phì, đất dốc, ferralic acrisol, Thái Nguyên
Effects of long-term N fertilization for cassava on soil fertility of sloping ferralic acrisols in Thai Nguyeen province
Long-term N application tended to increase soil total C, N, S and extractable Al, but to reduce soil total P and K with no significance at P<0.10. However, long-term N application increased soil extractable NH4-N, S but reduced soil extractable P, K and Mg. Moreover, NH4-N and Al supply rates increased with increasing N rates but Mg supply rates decreased significantly. Soil nutrient supply rates measured by ion exchange membrane performed well in acid soils. Further method development for P is required in order to use the resin membranes effectively in high P fixing and low P content soils such as these.