Evaluation of grape quality and relationship between grape quality and soil texture
葡萄品质的评价及其与土壤质地的关系研究

The grape quality and soil texture were analyzed in the main grape production base of Zhuolu in Hebei Province.The analytical hierarch process and K-means cluster were applied to evaluate the main indices of the grape quality, which include soluble solid concentration, weight of single fruit, the ratio of soluble solid concentration to titrated acidity, pH and Vc. The soil mechanical composition was also determined in 0～60 cm horizons and the correlation between the indices of grape quality and soil fractions was also studied. The results showed that ①The weights of single fruit were >6.0 g for the first grade, >5.0 g for the second grade and <5.0g for the fourth grade. The soluble solid concentrations were > 175 g/kg for the first grade, > 160 g/kg for the second grade and <130 g/kg for the fourth grade; the excellent ratio of soluble solid concentration to titrated acidity varies from 20 to 30. ②There was significant positive correlation between the weight of single fruit and the fine sand fraction, a significant negative correlation between the weight of single fruit and the physical clay fraction and between also soluble solid concentration and the fine silt fraction. There was significantly or extremely significant negative correlation between soluble solid concentration and the physical clay fraction, a significant or extremely significant positive correlation between the ration of soluble solid concentration to titrated acidity and the coarse sand fraction.③The soil texture were all light loam for the high grape quality but were medium loam or heavy loam for the poor grape quality. Thus, soil texture, soluble solid concentration, weight of single fruit, the ratio of soluble solids concentration to titrated acidity can be used as the important indices to evaluate grape quality in Zhuolu.