Conventionally, in the plantations represented cedar, cypress, thinning, by forest maintenance died surprise, etc., it has been function of forest is restored if you ensure the forest illumination by reducing the stand density. However, where not recovered vegetation progressive acidification of the soil may be prominently because the period is maintained by the low illuminance longer has many plantation was planted in overcrowded. Also, even at a place which is strongly acidic soil pH is lowered significantly since it is a special soils acid sulphate soils, etc., can not be expected the improvement of the soil environment in a state of being left alone. Soil dressing comprising a mixture with (3) organic materials and (4) converter slag in (2) additional material consisting of (10) binder fertilizers (8) and (9) Seeds of the plant (7) and configured to supply the target area to be a (1) acidic relaxation based material that is added has a highly acidic soil soil pH is lowered to (1) the acidic relaxed base material (G).従来,スギ,ヒノキに代表される人工林では,間伐,抜打ち等の森林整備亡よって,立木密度を低下させることで森林内照度を確保すれば森林の機能が回復するとされてきた。しかし,過密に植栽された人工林内は低照度によって維持されている期間が長いことから土壌の酸性化の進行が顕著となって植生の回復していない箇所が多くなっている。また,酸性硫酸塩土壌等の特殊土壌であることから土壌pHが著しく低下して強酸性となっている箇所においても,そのまま放置した状態で土壌環境の改善が望めない。転炉スラグ(3)と有機質資材(4)とを混合してなる客土(2)に植物の種子(8)や肥料(9)及び粘結剤(10)からなる添加材(7)を加えたものを酸性緩和基盤材(1)とし,当該酸性緩和基盤材(1)を土壌pHが低下して強酸性土壌となっている対象地(G)に供給する構成。
