| 摘要 |
PURPOSE:To obtain soil having adequate intergranular voids of soil and good suitability for the growth of vegetable whose roots and stalks are edible even in hot or cold areas, by mixing granular polyurethane foam of a specific grain size with soil. CONSTITUTION:Dry soil is mixed with 10'60vol% granular rigid polyurethane foam of a grain size of 2-30mm, preferably 3-15mm, whereby the amount of voids in the soil is increased. Thus, water can penetrate deeply into soil through the voids when rain falls and also when rain stops, the soil receives water from large voids and air from small voids, increasing the absorption of fertilizer. Also, because of the small thermal conductivity of the polyurethane foam, the burning of the ground surface due to direct sunshine during the summer season is prevented and also, in the winter season, the lowering of temperature on the ground surface is suppressed, thus making the soil suitable for the growth of vegetables. |
