Study of phosphate species of chernozem and sand soils by heterogeneous isotope exchange with 32P radioactive tracer.

Weakly and tightly sorbed phosphate species on chernozem and humus sand are investigated by radioactive tracer method using 32P. The comparison of the heterogeneous isotope exchange of 32P-labeled phosphate of non-radioactively incubated soils and desorption of 32P-labeled phosphate of radioactively incubated soils shows the transformation of weakly sorbed species to tightly sorbed ones. The quantity of weakly sorbed phosphorus and the steady state phosphorus exchange rate between soil and soil solution, transformation half-life of weakly to tightly sorbed phosphate are calculated.