Effects of Chloropicrin, Dimethyl Disulfide and Metham Sodium Applied Simultaneously on Soil-Born Bacteria and Fungi

Abstract

The area used to grow high-value crops is currently decreasing because production in the same soil for many years increases soil-borne diseases that reduce crop yield and quality as well as farmer income. Soil-borne disease is effectively controlled by soil fumigation prior to planting. In this study, the five different types of soils that had been used to grow tomatoes, watermelon, cucumber, ginseng and ginger were collected from field plots with high incidence of soil-borne diseases. This experiment adopts the indoor fumigation method to conduct triple fumigation of chloropicrin(PIC), metham sodium(MS) and dimethyl disulfide(DMDS) on different soil collected to examine changes in the soil microbial community, including pathogenic fungi and bacteria and beneficial microorganisms in order to clarify the impact on the overall structure of soil microbial community while controlling complex and multiple pathogens. High-throughput gene sequencing was used to detect bacterial and fungal taxonomic changes in the treated soils. Triple fumigation significantly reduced the abundance of at least five kinds of pathogenic fungi, Fusarium oxysporum, Mortierella, Neocosmospora, Nitrospira Alternaria and significantly increased the abundance of two kinds of beneficial species, Bacillus and Trichoderma. The research result observed increases and decreases in the biodiversity and richness of beneficial and pathogenic bacteria and fungi in response to triple fumigation of soil that had been used to grow tomatoes, watermelon, cucumber, ginseng and ginger. The most significant effect was observed in the experimental field of Panax notoginseng in Wenshan, Yunnan. Triple fumigation showed good potential to decrease pathogenic bacteria and fungi in soils and improve the disease resistance of soils, and that it has a good application prospect in the field of soil disinfestation.