Responses of grape yield and quality, soil physicochemical and microbial properties to different planting years

As an economically important fruit crop, continuous cropping of grapes can potentially impact soil health resulting in decreased yields. However, the mechanism of how soil microecological environment affects grape quality at different growth stages is not fully understood. A field experiment was conducted to investigate the effects of continuous grape cultivation for 0, 7, and 12 (CK, G7Y and G12Y) years on soil physicochemical properties and microbial community at different growth periods and soil depths, as well as on grape yield and quality. The results showed that grape yield, aroma compound contents, soil and grape leaf nutrients decreased significantly with the increase of planting years, soil acidification and secondary salinization intensified. Compared to G7Y, the relative abundance of the beneficial soil microorganisms Mortierella, Bacillus and Pseudomonas decreased significantly in G12Y, while the relative abundance of the potential pathogenic fungi Pseudaleuria and Aspergillus increased significantly. In addition, the nutrient content and biomarkers in the subsoil were lower than those in the topsoil. Particularly, the fruit setting stage appeared to be more sensitive to shifts in soil microbial communities over different planting years. Correlation analysis showed that grape yield was positively correlated with Bacillus and Mortierella, and negatively correlated with Fusarium. Grape yield was more sensitive to phosphorus and potassium fertilizers than to nitrogen fertilizer. In conclusion, continuous cropping reduced the content of soil nutrients and the number of soil beneficial microorganisms, increased the abundance of soil pathogenic microorganisms, and jointly caused changes in grape yield and quality. Therefore, it is necessary to optimize the management strategies to improve the soil microbial diversities especially beneficial microbial diversity to maintain the soil health and then to promote sustainable production of vineyards.