| 摘要 |
Soil is improved for the growth of plants by providing a layer of synthetic resin foam beneath its surface. The foamed resin may be applied in the form of preformed pieces, or may be injected into the soil and foamed in situ. The preferred resins are urea-formaldehyde and melamine-formaldehyde resins, which may be used in conjunction with other resins, e.g. polyesters and phenolic resins. Also mixed with the foam there may be fertilizers, peat, humus, seeds and young plants. |
