Biodegradable mulching vs traditional polyethylene film for sustainable solarization: Chemical properties and microbial community response to soil management

Soil solarization is usually performed with polyethylene plastic films, which are often disposed of by taking them to landfills, burying them in soil, burning them or occasionally recycling them, and these approaches have a great impact on the environment. Therefore, the use of biodegradable films seems to be an interesting eco-sustainable alternative to traditional films. The effect of soil solarization carried out by using biodegradable mulch or traditional polyethylene plastic film was determined under greenhouse conditions. The response of the soil was assessed by chemical determinations and microbiological culture-dependent and culture-independent ap-proaches to evaluate the microbial biodiversity, biological status and quality of the soil. The biodegradable film avoided a high ammonia concentration in the soil, thanks to both lower soil water content and slightly lower temperature than polyethylene film, and these conditions probably have been optimal for growth of nitrifying bacteria, which were more efficient in BIO, as highlighted not only by lower ammonia value but also by higher nitrate value. Both films did not affect organic matter and total nitrogen content. Moreover, the modifications of the environmental and ecological conditions associated with the different film covers applied to the soils affected prokaryotic and eukaryotic populations, leading to the establishment of a new dominant microbial community. Interestingly, microbiological analyses highlighted a different behavior modulated with the two films indicating different times of recovery post stress. Overall, the results highlighted the potential of biodegradable film that appears to be a suitable replacement for traditional polyethylene plastic film for soil solarization, with great environmental benefits.