Biodegradable Plastic Mulch Films for Sustainable Specialty Crop Production

Plastic mulch films are employed in the production of vegetables and other specialty crops worldwide due to the benefits they provide, such as reduction of weeds and water loss by evaporation, and control of soil temperature. The benefits can lead to better product quality and yield, and to a more efficient utilization of agricultural inputs such as water. Unfortunately, polyethylene (PE), the most commonly employed constituent of plastic mulches, is poorly biodegradable, thereby requiring the mulch’s’ expensive and laborious retrieval after harvest. The opportunities for recycling and landfilling of PE mulches are not readily available or are impractical. Residual PE fragments are readily dispersed in soil-related ecosystems and watersheds, where they can harm micro- and macro-organisms. Biodegradable plastic mulches (BDMs) have been developed to address the disposal-related deficiencies. Although the purchase costs of BDMs are over two-fold higher than PE mulches, BDMs are inexpensively plowed into the soil after harvest. Despite the environmental benefits of replacing PE plastic mulches with BDMs, and potential savings of labor costs at harvest, the long-term impact of multiyear BDM employment on soil health and specialty crop productivity is still a concern. This chapter provides a review of BDMs in specialty crop production, including commonly employed polymeric constituents. The authors’ recent interdisciplinary research on the long-term impacts of BDMs on specialty crop production and soil fertility will also be discussed.