Utilization of short-term high temperature pretreatment for food waste composting: Effects of end-products on soil properties and plant growth

Short-term high-temperature pretreatment helps accelerate the composting process and improve compost product quality. The aim of this research was to clarify the role of high-temperature pretreatment compost (PHC) on soil and plant growth. We conducted an experiment in which PHC, traditional compost (PTC), and high-temperature pretreatment food waste (PFW) were used as organic amendments (OA). Each type of compost was mixed into purple soil at mass ratios of 3, 5, 10, and 20% to establish a soil-compost mixture; they were then used in pot experiments with Lolium perenne L. Plant growth-promoting effects were stronger in the three experimental groups with 10% OA than in groups with other mixing ratios (p < 0.05). Plant growth-promoting effects were strongest in the experimental group with 10% PHC, and Lolium perenne L. biomass, the chlorophyll content, and plant height were 1.1-1.3 times higher in this group than in the PTC and PFW groups. Soil physicochemical analyses revealed that OA at various mixing ratios could enhance soil nutrient levels, the humification degree, and enzyme activity, and the strength of the positive effects increased with the mixing ratio. The most pronounced soil amendment effects were observed in the PHC group at all mixing ratios (p < 0.05). Microbial analysis revealed that both the microbial diversity and relative abundances of unclassified_f_Rhizobiaceae and Terrimonas were significantly higher in the 10% PHC group than in the 10% PTC and PFW groups (p < 0.01). Correlation analyses indicated that urease, peroxidase, and sucrase activities were positively correlated with plant growth indexes. The correlation coefficients of unclassified_f_Rhizobiaceae with urease and Terrimonas with peroxidase and sucrase were 0.997, 0.878, and 0.863, respectively. PHC can promote plant growth by altering the dominant microbial communities and enzyme activity in the soil. This study provides a theoretical basis for the application of high-temperature pretreated compost products.