Compost induces the accumulation of biopesticidal organic acids during soil biosolarization

Abstract Current agricultural soil pathogen control methods that rely on fumigation with toxic synthetic chemicals are not sustainable. Combining soil organic matter amendment with soil hydrothermal treatment via solarization is a biological pest control alternative to chemical fumigation. The application and bioconversion of readily-available organic amendment resources, such as green wastes (GW), have not been considered. The impact of compost inoculum on the bioconversion of GW to pesticidal volatile fatty acids (VFAs) in soil during solarization was investigated. Laboratory experiments showed a significant positive effect of compost inoculum at a rate ≥ 1% on aerobic and anaerobic decomposition of GW, but only when soils were heated. Field trials showed that GW induced conditions in soil that supported fermentation and resulted in accumulation of VFAs. When soil was inoculated with compost, VFA accumulation was enhanced at increasing soil depth. The results indicate that green waste bioconversion can be used to improve pest control conditions in soil during solarization. The findings have environmental implications on green waste management and use of toxic synthetic chemical fumigants.