Efficiency of different solarization-based ecological soil treatments on the control of Fusarium wilt and their impacts on the soil microbial community

Fusarium wilt is considered one of the most destructive soil-borne diseases. Solarization-based soil treatments for the control of Fusarium wilt are considered ecological and are widely used. In this study, differences in the efficiency of Fusarium wilt control and the impact on the soil microbial community were investigated among three types of solarization-based soil treatments, including soil solarization (SS), soil solarization with flooding (SS-F), and soil solarization with organic amendment and flooding (SS-OA-F). The SS and SS-F treatments partially killed the Fusarium oxysporum over the first 6 days. However, these treatments had no or little effect on the deteriorated soil environment and soil microbial community. The remaining Fusarium oxysporum proliferated quickly after cucumber planting, and serious Fusarium wilt still occurred in the SS and SS-F treatments at the second planting. SS-OA-F significantly improved the efficiency of Fusarium wilt control. Soil Fusarium oxysporum were killed in greater numbers in a shorter time by SS-OA-F. The deteriorated soil environment was remediated over the 15-day treatment process due to increases in the acidified soil pH and reductions of the soil electrical conductivity. SS-OA-F also had a notably impact on the soil microbial community. The proportion of anaerobic microorganisms greatly increased, and that of aerobic microorganisms greatly decreased in SS-OA-F soil. The proliferation of soil Fusarium oxysporum was significantly inhibited after the SS-OA-F treatment. However, different organic matter types used in SS-OA-F resulted in different suppression durations. Compared with glucose, Medicago sativa amendment increased the soil bacterial diversity and prolonged the suppression duration.