Fabrication of waste bread-derived biodegradable mulch film with sustained-release atrazine performance.

Traditional agricultural techniques for the growth of agricultural demands and global population, such as polyethylene mulch film (PEMF) and herbicide, result in the problems of white pollution and herbicide contamination. Meanwhile, food waste is also a growing problem, producing millions of tons of discarded bread every year. Therein, waste bread was humified into fulvic-like acid (FLA) and K+-enriched bread crumb, and then it was mixed with talc powder, gelatin, glycerol, and atrazine (ATZ) to prepare a biodegradable mulch film (FTGG@ATZ) through molecular interaction. FTGG@ATZ not only had moisture retention and thermal warming effects similar to PEMF, but also possessed comparable hydrophobicity and flexibility. Besides, the final release of FLA and ATZ from FTGG@ATZ reached 94 % and 88 %, which had dual functions of slow-release multinutrient and herbicide. Furthermore, pot experiment demonstrated that FTGG@ATZ could effectively increase the yields of corn by 121.7 % and 37.8 % compared with Blank and PEMF groups, and increase weed inhibition ratio by 70 % compared to ATZ only. Notably, FTGG@ATZ showed an outstanding degradability with a rate of 74.5 % within a month and increased the relative abundance of beneficial bacteria (such as Bacillus). Additionally, earthworms experiment indicated that FTGG@ATZ had a high biosafety and could improve soil quality. Thus, the innovation of this study is the successful preparation of biodegradable mulch film through waste bread to realize the integration of fertilizer, pesticide, and film. It also provides a facile and viable strategy to mitigate the problems of plastic and herbicide pollution as well as food waste.