Characterization of soil phosphorus in different land use over calcareous soils by chemical extraction methods and 31P-NMR spectroscopy

Resumo

Many natural ecosystems around the world have been altered by human activities such as clearing for agriculture and pasture or timber harvesting. These land-use changes modify soil P status and dynamics. To evaluate the effects of land-use change on P chemical forms we used chemical fractionation and ³¹P-NMR spectroscopy. Soil samples were collected in calcareous moors in Castilla y León region (Spain) at 4 different depths and in three different land-use systems: natural holm-oak forest, affforested pine forest, and agricultural land. Our results indicated that land-use change from holm-oak forest to cereal crops increased orthophosphate P concentrations and P availability due to phosphate fertilization. However, soil phosphorus distribution in pine forest was similar to that in native oak forest.