Liquid mulch films based on polysaccharide /furfural Schiff base adducts with pH-controlled degradability

Liquid mulch, as a novel biodegradable mulch, can keep soil temperature and moisture, and also has the advantages of being applied without terrain restriction and biodegradable. However, the biodegradation of ordinary liquid mulch is not controllable and cannot meet the needs of different crop growth periods. In this study, we formulated a liquid mulch film (LMF) with pH-controllable degradation based on furfural and carboxymethyl chitosan, with polyvinyl alcohol, xanthan gum, and biochar added to improve the resistance to water solubility. The resulting LMF exhibited better mechanical strength and decreased light transmittance, air permeability, and water vapor permeability than commercial liquid mulch film (CLF). Compared with bare soli, LMF effectively reduced soil moisture evaporation and increased soil temperature, resulting in the growth promotion of cowpeas and maize with longer and thicker roots. Moreover, citric acid spraying could promote the degradation of LMF (9.26±1.64 %) and increase the abundance of beneficial bacteria in the soil. Overall, our study designed the controlled degradable LMF, which not only enhances crop growth but also fosters sustainable agricultural development.