地膜覆盖栽培机械化技术（续４）□张培增张建中（上接１９９７年第４期第１６面）（五）废旧地膜的回收和利用目前我国生产的地膜，大部分是以热塑性高分子化合物高压聚乙烯为基本原料，添加增塑剂、增色剂等制成的。这类地膜在土壤中不能被溶解，不仅给耕作和田间管理带... (Continued 4) □ Zhang Peizhong Zhang Jianzhong (Continued on the 16th of 1997, No. 16) (E) recycling and utilization of waste film At present, China’s production of plastic film, most of the thermoplastic polymer compounds are high-pressure polyethylene For the basic raw materials, add plasticizers, toner and other made. This type of film can not be dissolved in the soil, not only for farming and field management ...