林木稚苗の栄養生理に関する研究 [第VII報] : スギ, ヒノキ, アカマツ及びクロマツ稚苗における肥料要素含有量に関する2-3の綜合的考察

Abstract

The considerations in this report were carried on to obtain the basic materials for fertilizer-management of young trees in the nursery or forest. Then, I atempted to discuss on the characteristics regarding to the nutritive physiology, especialy connected with the average content and its seasonal changes and process of absorption of the nutritive element in the seedlings and on the factors which effect upon these conditions. Four main planting species in Japan, Sugi (Cryptomeria japonica D. Don, ), Hinoki (Chamaecyparis obtusa S. et Z.), Akamatsu (Pinus densiflora S. et Z.), and Kuromatsu (P. Thunbergii Parl.) were chosen to make comparative study. 1. The resulto of chemical analysis of the seedling are shown in consultation Tables 1-3, which were carried out by S. Tsuda or T. Shibamoto and others, and Tables 5~8 which were experimented by auther at Shirahama Experimental Forest, in 1956. 2. From these results, when we show the content of each element (N, P2O5, K2O and CaO.) in Sugi seedlings as 100, index number of them in other species is as shown in Tables 2-A, and when we show the content of Nitrogen in each species as 100, index number of P2O5, K2O and CaO is Table 2-B. As we can see in these tables, Sugi and Hinoki are considerably different from Akamatsu and Kuromatsu in the ratio of four elements, especaly in K2O and CaO, that is to say, Hinoki contains N and P2O5 more than Sugii, Akamatsu and Kuromatsu contain very much N, and very little CaO comparing with Sugi or Hinoki. 3. An analytical result of nutritive elements in several local forms in Kyushu-district is shown in Table 4. It is tliat there are some difference connected with the content of the element among these local forms, but the sure conclusion must be remain untill to be assumed by repeated examinations. 4. Some examples of the relation between the quantity of nutritive elements which were supplied and the content of the elements in the seedlings is shown in the Tables 5~8. From these results, it may be presumed as follows. (1) When very small quantity of nitrogen is fertilized, in case of Hinoki, the content of Nitrogen in all parts of the seedlings decreases, and also in case of Akamatsu or Kuromatsu, there are nearly same effects. (2) In the case of P2O5 which was limitted in quantity fertilizing, in many species, there is a tendency to decrasing the content of P2O5 in leaves, but in the case of K2O, there are no such effects except in Sugi. (3) Generally, in almost all species, the content of nutritive element (except N.) in fertilized seedlings is higher than these nonfertlized seedlings. (4) When two times of normal quantity fertilizer is applied, there is a tendency to increase the content of N and K2O. (See Table 9) 5. How dose deficiency of one elemement effect on the content of the elemen in tseedlings?. The results of experiments are as shown in tables 11-a and b. In this experiment, two elemerts are given enough and one element is not given. (1) Effect of N-deficiency is very clear on the content of N in all parts of Hinoki or Kuromatsu seedlings. (2) Effect of P-deficiency is noticeable on leaves of Sugi and Hinoki. (3) When K is deficient, Ca-content rises in Sugi seedlings, but in other species such effect are not find. I suppose that there is an antagonism between K2O and CaO. (4) Acording to the experiment by S. Miyazaki and others, in the case of Sugi seedling, if Ca is deficient, the content of P2O5, K2O and. MgO rise and on the other hand the content of CaO decreases. (See Table 12). Therefore, they recognized that there is an antagonism between CaO and MgO. 6. We examined with radio Isotope P32 to find out the seasonal variation of the absorption of phosphorus. Acording to the results of these experiments (See Fig.1 and Table 14), count number in leares by P32 absorbed are highest in June or August in the case of Sugi or Hinoki seedlings, but in December in case of Akamatsu or Kuromatsu. 7. On the seasonal variation of content of nutritive elements in seedling. (1) Seasonal variation of P2O5-content is shown as Fig. 2 and Table 15. It seems to be highest in July or August in the case of Sugi and Hinoki, but in the case of Akamatsu and Kuromatsu is higher in December. (2) In almost all seasons, the contents of P2O5 in Akamatsu and Kuromatsu are higher than these of Sugi or Hinoki. 8. On the rates of three parts; leaves, stems and branches and roots; and on the total quantity of nutritive elements per one seedling. (See Table 16, 17 and 18) (1) Weight percentages of the three parts of the seedlings will be change by the influences of cultivating conditions. But in generaly, it is occupied 45~55% by leaves, 20~30% by stems and branches. (2) Rates of quantity of nutritive elememt containing in three parts of seedling are as follows. 60~75% of each element except CaO in leaves, 10~30% in stems and branches. 9. From these things mentioned before, I suppose that it is desiable to change the rate of the elements and season of fertilizing for Sugi and Hinoki against to Akamatsu and Kuromatsu. But we can not yet reach to the certain conculsion for them. I hope you will give me kindly advice.