关键词: 土壤修复, 厌氧土壤灭菌法, 土壤退化

Abstract: Continuous cropping of watermelon has become increasingly common in China. However, yield and quality of watermelons are seriously affected by soil degradation caused by continuous cropping due to soil acidification and proliferation of Fusarium oxysporum f. sp. niveum (FON). In the present study, anaerobic soil disinfestation (ASD) was used to treat soil samples collected from dry farmlands and paddy fields used annually for planting watermelons. Each soil category was divided into 5 groups, namely: (1) controls (H1, S1), (2) flooded controls (H2, S2), (3) flooded and incorporated rice straw alone (H3, S3), (4) flooded and incorporated rice straw with sulfur powder (H4, S4), and (5) flooded and incorporated rice straw and ammonia water (H5, S5). Each group had 15 replicates. The soil samples were then placed in plastic bags, mixed thoroughly, sealed, and incubated outdoors for 20 days. Pot experiment was then performed to test the effect of ASD by planting watermelon seedlings instead of grafting. Results showed that the NO^-₃-N and SO₄^2- contents in soils were reduced significantly by ASD (P<0.05), while the pH values of the soil were elevated. The EC values of the soil were effectively adjusted, and the soil-borne pathogenic FON was remarkably suppressed (P<0.05). The mortality rate of the control group was 43.3%. The treated groups had better watermelon growth than the control group, and the watermelon yields of all the treated groups were higher than that of the control group. It was concluded that the ASD method could repair and improve degraded soil caused by continuous cropping.

Key words: soil remediation, anaerobic soil disinfestation, soil degradation