柿樹の養分吸収量について(第2報)

抄録

(1) In order to estimate the amounts of the nutrient elements absorbed by 25 year old Japanese persimmon trees (Fuyu), trunk circumference .and linear growth of branches, leaves and fruits were weighed and analysed.
From this datum, amounts of growth and nutrient elements absorbed for one year by the tree were calculated.
In addition, amounts of nutrient elements contained in branches pruned in winter were estimated.
(2) The dry weight of new tissues in these trees was as follows.
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(3) Total amounts of nutrient elements contained in new tissues were as follows (per tree).
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Sum of these elements in shoots leaves and fruits was 70% of N, 68% of P₂O₅, 79% of K₂O, respectively, of total of these elements in all new tissues.
(4) Average amounts of the nutrient elements absorbed by these Japanese persimmon trees were 9.96kg of N, 2.36kg of P2O5 and 9.24 kg of K2O, when persimmon trees were planted at a rate of 18 trees per Tan(about 114 acre) and produced 452 Kan (1695kg) fruits.
(5) The amounts of absorbed nutrient elements, when yield of fruits was 100 Kan (375kg) per tan in 9 and 25 year old trees, were as follows.
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This datum showed that amounts of nutrient elements absorbed by 9 and 25 year old trees we-re almost the same.
(6) The amounts of nutrient elements contained in pruning branches were as follows (per Tan).
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The amounts of nutrient elements contained in pruning branches were 7_??_14% of total amounts of these elements absorbed by these trees.