樹路樹の生態に関する基礎的研究

樹路樹の生育状況と根囲桝土壌状態との関係について

抄録

This study intends to research the effect of the state of soil on the growth of street trees in the city. The most of street trees, generally, lost vigour. Growth effections is rather less by air pollution, but more by physical and chemical condition of soil and subsoil, showing vital forces of such trees. Principal reasons to show poor growth are considered following data:
1. Gravel and gravel horizon are frequent in soil.
2. There is hardpan in the subsoil.
3. Soil is hard and compact.
4. Soil water permeability is not favourable.
5. There is decline in soil water-holding ability.
6. Soil acidity is excessive alkalization.
7. There is lacking in major elements of fertilizer, especially nitrogen and phosphoric acid in soil.
8. There are contained too much injurious materials against growing in soil.