マメ科樹木根瘤菌の接種効果に関する研究 アカシア・モリシマの直播造林（第２報） ; Studies on the effects of seed inoculation With Rhizobium on leguminous trees. On the direct seedings of Acacia mollissima Willd．（2）

１．琉大付属演習林、首里試験地（沖縄本島島尻郡那覇市首里石嶺町在）において、アカシア・モリシマの施肥、接種による直播造林および苗畑における施肥無接種による播種試験を実施した。２．直播造林地（播き穴、３０×３０ｃｍ、深さ４０ｃｍ、施肥区は１穴当たり７０g、硫安、過燐酸石灰、硫酸加里それぞれ１:4:２の割合に施与）の無接種区は接種区に比較し苗高、根元径の各平均値が小さく特に施肥接種区に比較しその生長は劣悪で問題にならない。３．苗畑（施肥量１壺穴当たり２０g、混合割合は直播地に同じ）では直播造林地より各種作業、管理も集約に実施、環境殊に土壌条件は割合良好であると推定されたが、苗木の生長は直播造林地の接種区特に施肥接種区より不良であった。４．即ち本直播試験は予報の結果を現地において裏付け、確認したものであり、また自然に根瘤菌の存在が或る程度考察される本苗畑においてもその分布は不十分か皆無に近いと思われるので、少なくとも本試験に供した類似の場所等でアカシア・モリシマの造林を実施する場合は根瘤菌の接種と適当な施肥の併用は絶対に必要条件であると思料された。 ; 1.Experiments on direct seedings by inoculation of root nodule bacteria to Acacia mollissima Willd., together with fertilization test and on seeding experiments by fertilized and uninoculated of Acacia mollissima in a nursery were conducted at the Shuri experimental site in Demonstration Forest of the University of the Ryukyu, Ishimine-cho, Shury, Naha-cyty, Shimajiri District, Okinawa. 2.The experiment was designed to have four sections: (1) unfertilized and uninoculated sec., (2) fertilized and uninoculated sec., (3)unfertilized and inoculated sec., and (4)fertilized and inoculated sec. Seeds of Acacia mollissima Willd., were sown in hole (30×30×40cm) made in each section. The fertilized sections were received 70g of fertilizer (nitrogen sulphate, calcium superphosphate, and potassium sulphate, at the ratio of 1:4:2). The results of the experiment showed that the plants in the uninoculated sections were smaller in height and diameter on ground than those in inoculated sections in average, especially they were for inferior to those in the fertilized and inoculated section. 3.Another test was designed to raise seedlings of Acacia mollissima Willd., in a nursery, applying 20g of fertilizer per seeding hole. The fertilizer ingredients were the same as used above. Although the environmental conditions, especially soil, of the nursery was considered to be relatively better than those of the directly sown land, and the seedlings were intensively managed, they were inferior in growth to those of the inoculated section, especially to the ...