Additives Improved Saprotrophic F Ungi For Formation of Humic Acids in Chicken Manure and Corn Stover Mix Composting

The objective of this study was to analyze the effects of biochar (BC) and palygorskite (PG) on the succession of predominant fungi throughout composting of corn stover/chicken manure mix to influence the formation of humic substances (HS). Results indicated that both BC and PG promoted the polymerization degree of HS and formation of more humic acids (HA), and BC performed better than PG, 10% additive was better than 5%. ITS rRNA gene sequencing showed that the succession of predominant fungi was significantly affected by BC and PG, correlation between HS formation and predominant fungi indicated that BC and PG boosted lignocellulose-degradation fungi which could promote the degradation of fulvic acids (FA) and HM to form more HA. Fungi function analysis showed that 10% BC significantly increased saprotrophic fungi, and decreased pathogenic fungi. Therefore, addition of 10% BC was conductive to promote the formation of HA and improve compost quality.