PROBLEM TO BE SOLVED: To provide organic soil for plant growth useable in aspects of quality, volume an economy.SOLUTION: All of raw woody parts, raw leaf parts and bark parts of a tree in an ordinary condition where branches thereof are pruned or removed are chopped with blades of a tree chopper while the tree remains in raw state. The chopped tree is immersed in pyroligneous acid solution for about 27 days or more so that the chopped tree is rotted and becomes artificial humus soil. The artificial humus soil is pressed so as to be crushed into the artificial humus soil having short fiber shape. Bark of woods mainly comprising Japanese cedar is removed from its woody part and being abundantly piled up in a mountain form. Inside of the piled bark is kept in anaerobically fermenting condition and left about 3 years or more so as to form rotted bark. The rotted bark of woods mainly comprising Japanese cedar is pressed and crushed so that bark compost having short fiber shape is constructed. The artificial humus soil and the bark compost are mixed so that soil for plant growth is constructed.【課題】品質的、量的、経済的に使用可能な植物育成用の有機質土壌を提供する。【解決手段】通常の樹木を剪定または枝打ちした状態の、生の木質部や葉部や樹皮部の全てを、樹木細断機の刃により生のままで細断し、該細断後の樹木を、木酢液に約２７日以上浸漬することにより、該細断樹木を腐食させて人工腐食土とし、該人工腐食土を押圧することにより破砕して短繊維状の人工腐食土とし、杉を主体とする木材の樹皮を、木質部から剥がして大量に山状に積み上げて、該積み上げた状態の内部において、嫌気性発酵状態として、約３年以上放置して、腐食状態の樹皮を形成し、該杉を主体とする木材の腐食状態の樹皮を押圧することにより破砕して、短繊維状のバーク堆肥を構成し、前記人工腐食土とバーク堆肥とを混合して、植物植生用の土壌を構成する。【選択図】図１４
