Systematic review of biodegradable mulch film site suitability and adoption among farmers

Abstract

Given the increasing effects of climate change and land degradation on agriculture, plastic mulches could play a vital role in maintaining soil moisture, retarding soil evaporation, suppressing weeds, and controlling soil temperature in marginal lands. These vital roles provide valuable services that reduce irrigation requirements, decrease the use of inorganic herbicides inputs in weed control, and reduce nutrient leaching. However, plastic mulch materials take a longer period to degrade and are associated with ecologically and agronomically detrimental outcomes. For instance, plastic mulch requires more labor and financial investments for removal and disposal. In addition, micro- or nanoparticles may persist in soil and negatively affect microbial activity, physical soil properties, and nutrient availability. As such, biodegradable mulch films are being developed as a sustainable alternative to plastic films and are designed to be integrated into the soil after use where they are degraded by local soil microorganisms. Despite its environmentally sustainable prospects, adoption and utilization of biodegradable mulch films among farmers are reported to be limited. Among the factors impeding adoption include predictability of degradation rate across local conditions, impacts on yields, and effectiveness at preventing weeds or retaining soil moisture. Although research into the degradation rate and adoption is ongoing, there exists limited synthesis of evidence across studies and sites. This impedes ability to effectively identify gaps in biodegradable mulch knowledge, establish evidence for best-practice, and help inform policymakers and producers. Therefore, this study seeks to conduct a systematic review of factors that influence biodegradable film utility for crop production.