关键词: 腐植酸, 可降解地膜, 生物降解性能, 土壤微生物

Abstract: This paper studied the biodegradation of humic acid degradable mulching film  by observing microbial growth through experiments of microbiological degradation and controlled soil-buria. Meanwhile, the weight loss was also measured during degradable mulching film degradation. Microbial number and soil enzyme activities in mulched film soil were tested to explore the impact of used plastic film on the metabolic activities of microbes. The results showed that microorganisms stimulated the degradation of mulch film, fungi played obvious role in film degradation, and film with the highest starch content had fast degradation speed. The intermediate product during film degradation could  increase soil microbial number and color their biochemical activity. Compared with the soil without plastic film, the numbers of bacteria, fungus, and actinomycetes, activities of catalase and sucrase, soil respiration in the soil covered with plastic film were increased by 205.1%, 110.4%, 46.9%, 156.2%, 198.6%, and 24%, respectively. The influences were related not only to the content of humic acid, but also to the degradation degree of the film.

Key words: humic acid, degradable mulching film, biodegradability, soil microorganism