Relationship between the available copper content in soil and the copper content of flue-cured tobacco in Enshi tobacco-growing areas | 恩施烟区土壤有效铜含量与烤烟铜含量的关系

Chinese. 以湖北恩施烟区有代表性的宣恩县和咸丰县为试验地点，分析其土壤有效铜含量与烤烟铜含量的关系。选取湖北恩施烟区不同海拔高度（600~1 500 m）地区的129个土壤样本及不同品种（云烟87，云烟85和K326）和不同等级（下橘（X2F）、中橘三（C3F）和上橘（B2F））的124个烤烟样本，测定土壤有效铜含量和烤烟铜含量，研究二者之间的关系。（1）恩施烟区土壤有效铜含量为(1.45±1.99) mg/kg，变幅0.17～9.88 mg/kg；其中土壤有效铜含量≥0.2～1.0 mg/kg的样本最多，占65.12%。土壤有效铜含量与土壤pH关系密切，当pH＜5.5时，土壤有效铜含量最高；当pH≥5.5～5.9时，土壤有效铜含量最低；当pH≥5.9时，土壤有效铜含量中等。在海拔高度600～1 500 m，土壤有效铜含量随海拔高度的增加呈先降低后升高的变化趋势。土壤有效铜含量随土层深度的增加而降低。（2）恩施烟区烤烟铜含量平均为(6.62±6.74) mg/kg，变幅为1.26～34.30 mg/kg，与巴西优质烤烟铜含量（4.90～10.60 mg/kg）符合频率为29.31%。不同品种、等级烤烟之间铜含量差异显著，不同海拔高度地区烤烟之间铜含量差异不显著。不同品种烤烟铜含量依次为云烟87＞K326＞云烟85；不同等级烤烟之间依次为B2F＞C3F＞X2F；不同海拔高度地区烤烟之间依次为低海拔＞高海拔＞中海拔。（3）随着海拔高度的增加，烤烟铜含量与土壤有效铜含量均呈现出先降低后升高的变化趋势。随着土壤有效铜含量的升高，烤烟铜含量也升高。烤烟铜含量与土壤有效铜含量在不同pH范围表现出相同的变化趋势。土壤有效铜和烤烟铜含量之间存在正相关关系。

English. Based on the representative locations of different altitudes of Xuan’en and Xianfeng in Enshi tobacco-growing areas, the relationship between copper content in soil and flue-cured tobacco was analyzed. 129 soil samples and 124 tobacco samples (contain Yunyan87, Yunyan85 and K326 which of three gradings of X2F, C3F and B2F) were selected to study the copper content in soil and copper content of flue-cured tobacco and their relationship. (1) The available copper content in soil in Enshi tobacco-growing areas ranged from 0.17 mg/kg to 9.88 mg/kg with the mean of (1.45±1.99) mg/kg, and the soil samples took a major proportion for the available copper content of ≥0.2~1.0 mg/kg. The available copper content in soil was closely related to pH. When pH was lower than 5.5, the available copper content in soil was the highest; when pH value was between 5.5 and 5.9, the available copper content in soil was the lowest; when pH was bigger than 5.9, the available copper content in soil was medium. The available copper content in soil decreased first, and then increased with altitude height (between 600 m and 1 500 m) going up. The available copper content in soil decreased with the soil depths deepening. (2) The copper content of flue-cured tobacco averaged (6.62±6.74) mg/kg, with amplitude of 1.26C34.30 mg/kg, and coincident frequency for Brazil's (4.90C10.60 mg/kg) was 29.31%. There existed significant differences among various cultivars, different gradings for the copper content of flue-cured tobacco, but not for the different altitudes. They showed the trends of Yunyan87K326 Yunyan85, the trends of B2FC3FX2F, and the trends of lower altitude high altitudemiddle altitude respectively. (3) The copper content of flue-cured tobacco and the available copper content in soil both increased with the altitude height going up. The copper content of flue-cured tobacco increased as the available copper content in soil increased. In addition, the copper content of flue-cured tobacco and the available copper content in soil showed similar trends in different pH scopes. There exists a positive correlation between available copper content in soil and copper content of flue-cured tobacco.