生物降解膜降解、保墒增温性能及对玉米生长发育进程的影响

Property of biodegradable film degradation,water-retention and increasing soil temperature and its impact on maize growth and development process

通过3年试验,研究生物降解膜降解、增温保墒性能及全覆盖双垄沟播玉米苗期0-25 cm土壤温度动态和对玉米生长发育进程的影响,明确生物降解膜在生产中对普通农用地膜的可替代性。结果表明,生物降解地膜埋入土壤约30 d左右可以观测到降解效果,40 d以后开始快速降解,到80-90 d时降解可达到85%-95%,种植地膜玉米后,压入土壤或地膜上有土覆盖的部分同样有明显的降解效果,而垄上的地膜在玉米收后绝大部分仍与常规膜一样保持完好;生物降解膜保墒性能达普通农用地膜的90.4%-95.4%;作物生育前期0-25 cm土层08∶30、14∶30和20∶30平均温度比普通农用地膜低0.85℃,比露地高1.91℃;生物降解膜全覆盖双垄沟播玉米比裸地平作出苗提前5-9 d,成熟期提前11-12 d。生物降解地膜具有一定的增温、保墒作用,降低生产成本后,可在一定程度上替代不能降解的普通农用地膜。

With the extensive use of plastic film to elevate soil temperature as well as soil moisture content in arid farmland in northern of China, pollution of residual plastic film has become the urgent ecological concerns. To mitigate the pollution of farmland plastic film and improve water use efficiency in rainfed areas, three years of filed experiments were conducted to study the property of biodegradable film degradation, and its effect on soil water- retention and temperature under the planting pattern of film mulching on double ridges and growing corn in furrows. The results showed that biodegradable film was observed to be decomposed about 30 days after mulching, and began to be rapidly decomposed after 40 days, with 82% of it degraded until 80 - 90 days. The partially mulched film on ridge was basically the same as common plastic film remaining intact after harvesting, but the partly landfilled in furrow was decomposed significantly. Water-retention of biodegradable film was 90.4% - 95.4% of common plastic film. The average temperature in 0 - 25 cm soil of full biodegradable film mulching on double ridges and planting corn in furrows was increased by 1.91℃ in comparison with non-mulching, and was reduced by 0.85℃ in comparison with full plastic film mulching. Emerging date was advanced 5 - 9 days and whole growing period was shortened 11 - 12 days. Degradable mulch film had the effects of increasing soil temperature, moisture-keeping, and therefore will replace common film if lowering the production cost.