Characteristics Of Terroir And Its Influence On Grape And Wine Quality In Zhangxuan Producing Area Of Hebei Province

Zhangxuan wine-grape producing area is located in the golden geographical location of wine-grape planting in the world,with unique climatic conditions and rich and diverse soil resources,suitable for different types of grape growth and wine production.As an important index for growers to evaluate and promote grapes and wine of origin,terroir provides a new idea for the quality development of wine grape industry in Zhangxuan producing area,and also indicates that it is necessary to study the key terroir conditions affecting grape quality and wine quality.By analyzing the climatic conditions(water,light and heat)and soil conditions(physical,chemical and biological properties)of different wine grape parks in Zhangxuan producing area,this study also determined and analyzed the quality indexes of wine grapes and wine in local parks,so as to understand the characteristics of wine grape parks and the differences of grape and wine styles under the interaction of terroir factors.To judge the key factors of characteristic development of grape producing area.The main research results are as follows:(1)The climatic conditions in Zhangxuan producing area are suitable,with frost-free period of178～227 days,effective accumulated temperature of≥10℃ of 1 499.7～2 025.2 ℃,annual average temperature of more than 8℃,diurnal temperature range of more than 11℃,active accumulated temperature of ≥10℃ of 3 598.3～4 078.6℃,sunshine duration of 2 789.0～2 900.8 h.The daily illumination rate is 57%～71%,the annual precipitation reaches 366.4～387.6 mm,and the water heat coefficient is less than 1.5 1～3 months before the grape ripening stage,which has the climatic conditions for the production of fine wine.In Huailai,Zhuolu and Yangyuan,the water heat coefficient of the wine grape varieties at maturity in October were all less than 1.0 in the month before harvesting,which had the climatic conditions for producing the best quality wine.The climatic conditions of Huailai and Zhuolu regions were better than those of Xuanhua and Yangyuan regions,which both met the growth and development requirements of wine grapes in different ripening periods.(2)The soil texture types of vineyards in Zhangxuan area are mainly sandy loam and loam,with bulk density ranging from 1.23～1.70 g/cm3,total porosity from 35.84%～53.70%,and water storage from 9.68～74.38 mm.The soil pH value and nutrient content were higher on the surface.According to the nutrient grading evaluation criteria,the soil is alkaline(>8.09),and the contents of organic matter and exchangeable magnesium were low,which were below the medium level.The content of soil alkali-hydrolyzed nitrogen,available phosphorus,available potassium,available sulfur,available zinc,available boron and total potassium were above the medium level.The contents of exchangeable calcium,available iron,available manganese and total phosphorus in soil were above the rich level.The content of available copper and available molybdenum in soil is below the level of deficiency.The contents of total nitrogen,total copper and total zinc in soil were all distributed in each nutrient classification,and about 50%of the soil was below the deficiency level.In addition to the higher soil catalase activity in the bottom layer,the higher soil sucrase,urease and alkaline phosphatase activities in the surface layer is similar to the distribution of nutrient content.The content of chromium in soil heavy metals is at the level of light pollution and moderate pollution,and the content of arsenic in some parks is at the level of light pollution.(3)Among the grape fruit quality in the sampling park,the Cabernet Sauvignon fruit tightness in Tumu town was the highest,which was 12.18%;The contents of soluble solid,solid acid ratio,seed total phenol and seed tannin in Noble Chateau Cabernet Sauvignon fruit were the highest,which were 22.02%,53.29,27.12 mg/kg and 24.16 mg/kg,respectively;The content of anthocyanins in Cabernet Sauvignon peel of Wanteng Wine Base was the highest,which was 7.26 mg/kg;The kernels per spike,pH,total phenolic and tannin contents in Chateau Martin Marselan fruit were highest,which were 171 varieties,3.71,16.47 mg/kg and 16.12 mg/kg,respectively;Chateau Shengtang No.24 Chardonnay fruit had the highest titratable acid content(0.84%);Sandaowan Base longan grape ear length was the longest,which was 19.70 cm;The single ear weight and 100 grain weight of Longan grape from Waihugou Grape King were the highest,which were 809.89 g and 724.43 g,respectively.(4)Correlation analysis of grape fruit quality indexes showed that ear length,ear weight,100 grain weight were positively correlated with titrable acid,but were negatively correlated with other indexes except skin tannin and kernel number per ear.There was a positive correlation between phenolic indexes.The comprehensive score of principal component analysis showed that the best fruit quality of the same grape variety planted in different parks were Noble Chateau Cabernet Sauvignon grape,Chateau Martin Marselan grape,Chateau Shengtang No.13 Chardonnay grape and Sandaowan Base Longan grape.Grey correlation analysis showed that frost-free period,annual sunshine duration and effective accumulated temperature>10℃ were important meteorological factors affecting the comprehensive quality of fruit,and available phosphorus,available copper and exchangeable magnesium were important soil factors affecting the comprehensive quality of fruit.The regression analysis of climate and soil factors on grape quality showed that the increase of total copper,available zinc and exchangeable calcium in soil was conducive to the improvement of fruit appearance quality,but not conducive to the formation of basic chemical indexes and phenols.Soil available phosphorus,available sulfur and average daily temperature range were beneficial to the accumulation of fruit solid acid ratio and total seed phenol,seed tannin and peel phenol,respectively.(5)Among the wines collected from different regions,the contents of total phenol and tannin in Cabernet Sauvignon wine of Noble Chateau were the highest,which were 2 456.92 mg/L and 502.40 mg/L,respectively.The soluble solids,solid acid ratio and pH in Marselan wine of Chateau Martin were the highest,which were 8.17%,20.46 and 3.55,respectively.The total anthocyanins and chroma contents of Marselan wine from Chateau Amethyst were the highest,which were 409.36 mg/L and 22.43,respectively.Chateau Shengtang No.24 Chardonnay wine has the highest titrable acid content at 0.68%.Waihugou Grape King Longan wine has the highest hue at 2.60.(6)Correlation analysis of wine quality indexes showed that phenolic indexes,chroma,pH and solid acid ratio were positively correlated with each other,but negatively correlated with hue.The comprehensive score of principal component analysis showed that the best quality wines of the same variety produced in different parks were Noble Chateau Cabernet Sauvignon wine,Chateau Martin Marselan wine,Chateau Shengtang No.13 Chardonnay wine,Sandaowan Base Longan wine,which was consistent with the comprehensive evaluation results of grape quality.Gray correlation analysis showed that soil pH value,total potassium and available phosphorus were important soil factors affecting the comprehensive quality of wine,while anthocyanins,total phenols and soluble solids of fruit peel were important fruit quality indexes affecting the comprehensive quality of wine.The regression analysis of soil factor and fruit quality index on wine quality showed that grape fruit quality index had more influence on wine quality.With the increase of anthocyanin content,the phenolic indices,chroma,pH and solid acid ratio of wine were improved,but the tint and titrable acid content were decreased.The increase of soluble solids in fruit is beneficial to wine chromaticity and total anthocyanins.The soluble solid content of wine was decreased with the increase of fruit weight.With the increase of exchangeable magnesium content in soil,solid acid ratio of wine can be improved.In conclusion,climate conditions in Zhangxuan producing area are suitable for the growth of early,middle and late maturing wine grapes.There are great differences in soil physical,chemical and biological properties in different wine grape parks,which is suitable for developing characteristic grape industry.The soil organic matter content in some parks is low,so organic fertilizer should be added in time.Appropriate application of magnesium fertilizer and copper,molybdenum and other trace elements fertilizer,regulate soil pH,reduce soil chromium content.The response of grape fruit and wine quality to terroir conditions in different wine grape parks makes the dominant quality indexes different.Therefore,we should pay attention to the development of wine grape and wine unique style in the cultivation process.