Study On Terroir Of Gezi Mountain Wine Sub-region At The Eastern Foot Of Helan Mountain Based On Soil And Variety Characteristics

The Gezi Mountain is a small wine sub-region at the eastern foot of Helan Mountain in Ningxia,China.Soil and variety are the two important factors that affect the wine terroir.In order to explore the climate,soil,grapes,and wine in the Gezi Mountain wine sub-region and to explore the internal relationship between "soil-berries-wine".In 2021,Xige Winery in Gezi Mountain was selected as the research basin.According to factors such as soil and variety,11 varieties and 14 sample plots were selected for the materials,including Gewurztraminer,Cabernet Sauvignon,Malbec,Merlot,Cabernet Gernischt,Dunkelfelder,Pinot Noir,Marselan,Petit Verdot,Chardonnay and Sauvignon Blanc.Based on various indicators of meteorology,soil,grapes,and wines,the methods such as heatmap analysis,cluster analysis,and mantel test correlation analysis were also used to analyze the relationship.The main results are as follows:1.The Gezi mountain has a typical continental monsoon climate,with cold and dry winters and hot summers being characterized with intense rainfall.The annual average temperature in 2021 is 18.4 ℃,with an annual precipitation of 167.3 mm,an effective accumulated temperature of 1862.0 ℃,and a frost free period of 176 days2.The soil type in the Gezi mountain includes sandy loam,sandy loam with stones,red clay,and calcareous soil.The soil texture is mainly sandy,including sandy clay loam,sandy loam,loamy sand,and clay loam;They are all alkaline soils with a p H of 8.0～8.5.The soil organic matter content in various areas ranges from 2.74 g/kg to 11.04 g/kg;The nitrate nitrogen content ranges from 0.28 mg/kg to 73.12 mg/kg;Ammonia nitrogen content ranging from 0.16 mg/kg to 8.25 mg/kg;The content of available phosphorus is 3.24 mg/kg～29.42mg/kg;The content of available potassium ranges from 36.22 mg/kg to 155.80 mg/kg.3.The sugar content of grapes is 164.0 g/L～246.5 g/L,and the titratable acid content is4.81 g/L～8.02 g/L.Wine alcohol content ranges from 11.10% vol to 16.62% vol,and titratable acid content ranges from 4.20 g/L to 6.26 g/L.4.The berry quality of the same variety in different soil type also showed significant differences.The berry weight,transverse and longitudinal diameter,titratable acid,sugar content,anthocyanins,flavonol and tannins in skin,the tannins in seed of Marselan in calcareous soil were higher than those in sandy soil,but the yeast available nitrogen(YAN)content was lower than that in sandy soil;The berry weight,transverse and longitudinal diameter,titratable acid,peel tannin and seed tannin of Dunkelfelder in calcareous soil are higher than those in sandy soil,but the sugar content,YAN,anthocyanin and flavonol content in peel are lower than those in sandy soil.5.There is a significant correlation between various indicators of soil characteristics:(1)The soil moisture content is negatively correlated with soil capillary porosity and total porosity,but positively correlated with electrical conductivity;(2)There is a significant positive correlation between soil p H and clay content,and a significant positive correlation between soil conductivity and available calcium content;(3)There is a significant positive correlation between soil organic carbon and total nitrogen and available phosphorus content;(4)There is a significant negative correlation between soil sand particles and available magnesium content,a significant positive correlation between soil powder particles and available magnesium content,and a significant positive correlation between soil clay particles and available magnesium content;(5)There is a significant positive correlation between soil total nitrogen,available phosphorus,and available copper content;There is a significant negative correlation between soil total phosphorus and total potassium content,a significant positive correlation with available magnesium,and a highly significant positive correlation with available zinc.6.There is a significant correlation between grape fruit quality characteristics and soil physicochemical properties:(1)There is a significant positive correlation between the basic physical and chemical indicators of grape fruits and soil available magnesium;(2)The tannin content in pericarp was significantly positively correlated with soil water content and soil texture,and also with soil available zinc content.7.There is a significant correlation between volatile substances in wine and soil physicochemical indicators:(1)There is a significant positive correlation between the esters in the volatile substances of wine and the ammonia nitrogen and available magnesium in the soil;(2)There is a significant positive correlation between higher alcohols in wine and soil moisture content,as well as a significant positive correlation with available zinc in soil;(3)There is a significant positive correlation between the fatty acids in wine and soil bulk density;(4)The benzene derivatives in wine have a significant positive correlation with organic carbon and total nitrogen in soil,and a highly significant positive correlation with available magnesium in soil.