抄録
Determination of phosphorus concentration in lake sediments and test of phosphorus release were attempted successfully. For the deep core from the sediments of Lake Kasumigaura, it was observed that the greatest content of phosphorus occurred at the depth of 0-5 cm, followed by decreasing content down to 15 cm and constant below 15 cm : this was consistent with the decrease of Fe-P content.
It was noted from the release test that bio-available phosphorus which stimulated algal growth was Fe-P. A relationship between pohsphorus amount released from lake sediments and maximum growth yield of Selenastrum capricornutum was presented.
Fe-P released into liquid at 55th day of anaerobic release test to a level of 90% of that retained initially with sediments of Lake Biwa.
