How long does a phosphate ion remain in the solution of agricultural soils

摘要

This work was conducted to assess the influences of soil properties and agricultural practices on the mean residence time of phosphate ions in the soil solution (T(sub m)). T(sub m) was measured with the isotopic exchange kinetics method on the surface horizon of 213 soils from Albania. Almost 90 per cent of the samples presented a T(sub m) value included between 10(sup 4) and 10(sup -1) minute. T(sub m) depended primarily on the soil iron oxide content, and was only slightly affected by current farming practices. As a consequence T(sub m) could be inferred from the parent material of the soil. Taking into account this parameter could therefore help in a better management of fertilization. (author). 5 refs.