Effects of agricultural plastic films on crop growth and soil health in tobacco fields: A comparative study

In recent years, the impact of microplastics on soil microorganisms and crop growth has gained significant attention. However, the effects of agricultural plastic films on crop growth and soil health in tobacco fields are not clear. In our study, we conducted field experiments to investigate the effects of six types of agricultural film treatments on soil fertility, soil microbial community, and plant growth. Compositions of study treatments were as follows: T1: farmhouse film; T2: photodegradation film; T3: black film (6 mu m); T4: black film (8 mu m); T5: transparent film (6 mu m); T6: transparent film (8 mu m). Our results showed that photodegradable film treatment was beneficial for promoting crop growth and root development. The fresh stem biomass, dry root biomass, and dry stem biomass were significantly increased by 14.58 %, 68.70 %, and 18.27 %, respectively, under the T2 treatment, when compared to the T1 treatment. In addition, our results showed that photodegradation film treatment maintained soil pH value, compared with other agricultural film treatments. The application of photodegradation film treatment offered advantageous effects in the preservation of soil moisture and temperature. In addition, the diversity of soil microorganisms improved with photodegradable film. Compared to T1 treatment, the number of OTUs of bacteria and fungi improved by 1.94-7.64 % and 7.39-30.08 % under other treatments, respectively. Furthermore, our study showed that pH emerged as the paramount environmental determinant. The number of subnetworks treated with photodegradable film significantly increased, indicating a more complex and stable functional diversity of soil microbial communities. Additionally, compared to bacteria, fungal communities exhibited greater adaptability and stability. The results of this study support the view that photodegradable film can be employed, as it can to enhance crop yield, improve soil quality, maintain a favorable ecological environment, and mitigate the adverse environmental impact of microplastics.