01667naa a2200169 a 450000100080000000500110000800800410001910000210006024500860008126000090016752012070017665000120138365000190139565300110141470000160142577300560144112795452025-01-20       1990    bl uuuu     u00u1 u    #d1 aGILLESPIE, A. R.  aA comparison of tree rock phosphates for use forest soils.h[electronic resource]  c1990  aThe use of rock phosphates in forestry is an important and economic alternative to soluble phosphorus sources for some soils. Interactions of tree rhizosphere processes and rock phosphates may increase availability and uptake efficiency, but interactions of rock phosphates in different forest soils may reduce availability. This study examined phosphorus diffusion rates in three forest soils fertilized with either of three rock phosphates of varying solubility. Diffusion rates were calculated from phosphorus buffer powers determined by desorption in pH adjusted solutions. Diffusion rates and rock phosphate solubilities were compared to quantities of phosphorus in whole-seedlings of black locust (Robinia pseudoacacia L.) grown in the experimental soils fertilized with the experimental rock phosphates. Results indicated that phosphorus uptake varied by rock phosphate solubility, but the pattern was different for each soil. Increasing solubility did not always increase phosphorus uptake. Diffusion rates with and without pH adjustment proved superior in predicting phosphorus availability in each soil and therefore may provide a better index for forestry use than rock phosphate solubility.  aFosfato  aSolo Florestal  aForest1 aPOPE, P. E.  tFertilizer Researchgv. 23, n. 3, p. 141-147, 1990.