Degradation property of degradable film and its effect on flue-cured tobacco development and soil ecological environment
Aiming at decreasing agricultural pollution caused by plastic film, degradation of photo-oxygen degraded and bio-degradable films and their effects on flue-cured tobacco development, soil temperature, moisture, enzyme activities and fungi community were studied. The results between plastic film covering and open field were compared. The results indicated that the degradation performance of bio-degradable film was better than that of photo-oxygen degradation film. The degradation degree of the two films applied to flue-cured tobacco in 245 days was degradation level 5 and 4, and the residual amount of the films was 40.1 % and 64.0 %, respectively. The development and biomass of flue-cured tobacco increased markedly with film covering compared to open field, and the effects of plastic film were best, followed by bio-degradable film, and lastly by photo-oxygen degradation film. In the early stage of tobacco plant growth, the temperature and moisture content of soil treated with two kinds of degradable film were higher than that of the open field, which was significantly lower than that of the plastic film. In the middle and later stage of the tobacco plant growth, it was similar to that of the plastic film, slightly lower than the open field. Film covering significantly increased the soil acid phosphatase activity, and soil enzyme activity of plastic film treatment was best, followed by open field and bio-degradable film. In addition, the number of fungi operational taxonomic units (OTU) in soil with bio-degradable film treatment increased by 12.7 % more than plastic film. The microbial abundance of Ascomycota and Basidiomycota in the soil promoted and decreased severely with the application of the two degradable films. The OTU species abundance of soil fungi with the treatment of open field was better than film-covered, and the soil fungi OTU uniformity of plastic film mulch was superior to other treatments. This illustrated that the microbial fungi community structure was more uniform and stable because the soil environment was less affected by the outside world with plastic film mulching. Bio-degradable film had excellent degradability and no significant difference in the development of flue-cured tobacco with plastic film, which showed that it could be applied to tobacco production.