Abstract
The diversity and community structure of soil fungi play an important role in crop production and ecosystem balance, especially in paddy-upland vegetable field systems. High-throughput sequencing was used to study changes in the soil fungal community structure and function in paddy-upland vegetable field systems. The results showed that compared with traditional planting, the diversity and community structure of soil fungi were changed by the combination of flooding and drought, the Shannon index increased by 11.07%, and the proportion of the dominant species, Mortierella, decreased by 22.74%. Soil available nitrogen, total phosphorus, available phosphorus, total nitrogen and organic matter played a leading role in the initial stage of the experiment, while the dominant factor changed to total potassium 3 years later and then to soil pH and water content 6 years later. FUNGuild analysis showed that the proportion of three independent trophic modes of soil fungi were increased by the combined flooded-drought model, and there were multiple interaction factors, For example, nutrient supply, pH and planting pattern. This study showed that soil fertility, crop yield and economic benefits were better than the traditional model after three years of planting and breeding. The longer the time, the better the effect.