Simple synthesis and excellent performance of the cow dung-based biodegradable liquid mulch for sustainable agriculture.

The environmental pollution caused by the extensive use of plastic films in farmland and the discharge of large amounts of manure from animal husbandry has seriously affected the sustainable development of global agriculture and environment. In this study, using cow manure as raw material, a cow dung-based biodegradable liquid mulch (CD-BA) was synthesized through grafting polymerization and as an eco-friendly alternative to the traditional agricultural plastic film. By studying the effects of the proportion of cow manure raw materials and additives on the performance of liquid plastic film, the optimal CD-BA was synthesized with 48.36 wt% of cow dung, 26.77 wt% of glycerol and 2.08 wt% of quartz sand (red soil), respectively. The soil test results indicate that CD-BA has the capability to reduce soil water evaporation by 15%-42%, which is marginally lower than the 67% reduction observed with plastic mulch. Its temperature-increasing capacity ranges from 0.63 °C to 1.21 °C, which is comparable to the capacity of plastic mulch. Moreover, CD-BA achieves a soil degradation rate of 41.2%-69.5% within 120 days, significantly addressing the persistent non-degradability issue associated with traditional plastic mulch. In plant experiments, CD-BA demonstrated a 97.5% inhibition rate on weed seed germination, whereas CD-BA positively influenced crop growth and its drought resistance. This study provides a feasible resource utilization method for simultaneously solving the environmental pollution problems of animal breeding waste and farmland plastic film.