Soil Fumigation Combined with Seed Rhizome Disinfection to Synergistically Promote Soil Health and Increase Ginger Yield

Soil-borne diseases have become increasingly serious due to continuous planting. Soil fumigation may be inadequate because of the persistence of soil-borne pathogens on ginger seed rhizome. A combined strategy of soil fumigation and seed rhizome disinfection would be necessary to achieve synergistic control. In this study, the approach of soil fumigation with chloropicrin (CP) coupled with seed rhizome disinfection (Copper, Cu) was first adopted to evaluate the synergistic effects on soil physicochemical properties, enzyme activities and microbial communities, and therefore reveal mechanisms for soil microecological health and crop yield promotion. The results showed the comprehensive strategy could reduce NO3−-N content, and the activities of soil enzymes, while increased NH4+-N content, EX-Cu, and OXI-Cu content, which were positively correlated with ginger yield but negatively correlated with soil-borne pathogens and plant mortality. On the other hand, there was a reduction in bacterial diversity and richness, which was positively correlated with the abundance of soil-borne pathogens. Moreover, some beneficial soil microorganisms’ relative abundance (such as Firmicutes, Actinobacteria, Bacillus, and Sphingomonas.) was increased. The strategy decreased the abundance of Fusarium spp. and Phytophthora spp. by 49.41–90.07% and 43.34–89.21%, respectively. Compared with other treatments, the combination decreased the ginger mortality by 5.70–57.02% and increased the growth of ginger plants and yield by 3.58–139.96%, and 13.11–399.74%, respectively. This study highlights a prospect to promote ginger growth and yield by blocking the transmission of primary infection pathogens in ginger cultivation and improving soil ecological environment.