Temporal and Habitat Dynamics of Soil Fungal Diversity in Gravel-Sand Mulching Watermelon Fields in the Semi-Arid Loess Plateau of China
Wenqing Zhou, Xin Zhou, Lei Cai, Qi Jiang, Rong Zhang
Abstract
Gravel-sand mulching is a traditional agricultural practice in arid and semiarid regions, providing a surface barrier for soil and water conservation. However, application of such practice in monocropping systems may lead to outbreaks of several devastating plant diseases, such as watermelon Fusarium wilt. Our results with amplicon sequencing suggest that soil fungal communities differ significantly between mulched farmland and mulched grassland and are more sensitive to gravel-sand mulch in grassland. Under continuous monoculture regimens, long-term gravel mulch is not necessarily detrimental and may result in decreased Fusarium abundance. However, some known beneficial soil fungi may be enriched in the gravel-mulch cropland as mulch duration increases. A possible explanation for the reduction in Fusarium abundance may be the formation of disease-suppressive soils. This study provides insight into the need to explore alternative strategies using beneficial microbes for sustainable watermelon wilt control in continuous monocropping system.