Relation of Forms of Phosphate to Absorption of Phosphorus by Tea Plant

The absorption of phosphates by the tea plant was examined with radioactive (32P) monocalcium phosphate, iron phosphate in pots filled with Makinohara plateau reddish yellow tea soil.The results were summarized as follows:1) In the 1st crop, radioactive phosphates were dressed 12 days before plucking tea leaves.The percentage of dressed phosphorus content to total phosphorus content in new leaves of the 1st crop was lower than 10% in every type of phosphate.2) These rates of three phosphate in new leaves and young stalks through the 1st, 2nd ane 3rd crop were as follows ; mono-calcium phosphate ?? iron phosphate>aluminum phosphate.These rates of mono-calcium phosphate and iron phosphate plot in young leaves and stalks were 40-70%, and that of aluminum phosphate plot was 35% in the 2nd and 3rd crop.3) These rates in young stalks were higher than that in young leaves of every plot.4) The transformation of radioactive phosphate in pot soil 90 days after dressing was. investigated.Fifty eight percent of dressed mono-calcium phosphate was transformed into aluminumbound phosphate and 19% of that into ironbound phosphate.Thirty five percent of the iron phosphate was transformed into aluminum-bound phosphate and 30% of the aluminum phosphate was transformed into iron-bound phosphate.