Effect of afforestation on potassium and phosphorous status in chernozem-like soils of mesodepressions in northern caspian plain

摘要

The change of the virgin steppe vegetation by oak stands on chernozem-like soils was found to result in the decrease of the exchangeable and easily exchangeable potassium content and K+ activity due to more intensive uptake of potassium by oak plants. Under the elm stands the proportion of phosphate fractions I and III was observed to have been increased probably because of the high content f Ca and Al in the elm litterfall.