On the Change of Forms of Phosphorus Added in the Tea Soils

Abstract

Phosphorus contents of Ca-, Al-, Fe-, combined and other insoluble type of the tea soils of Southern Makinohara plateau, derived from the yellowish red soils were determined. Furthermore, the change of forms of phosphorus added in the tea soils was examined with radioactive 32P.The results were summarized as follows:1. Generally, phosphorus contents of Al-, Fe- combined and other insoluble type were much and that of Ca- combined type was a little.2. The ratios of phosphorus contents of Al-, Fe- combined and other insoluble type to phosphorus content of Ca- combined type were comparatively small in the sandy tea soils but those of the clayey tea soils having strong acid were very large.3. The change of forms of phosphorus added to the tea soils was measured with radioactive 32P and it was detected that 70% of the added phosphorus was quickly transformed to the Alcombined type.4. It seems that these phenomena are due to the increase of active Al and Fe ions by the strong acid reaction in the tea soils.