亚热带茶园土壤酸度特征研究——以福建省武夷山市为例

调查测试福建省武夷山市60个茶园6个土类120个土层的土壤酸度指标,分析茶园土壤酸度特征,结果表明:福建省武夷山市茶园0~20cm土层土壤平均pH值为4.52,其中pH < 4.5的重度酸化土壤占总调查样本的55.00%;20~40cm土层土壤平均pH值为4.52,pH < 4.5占53.33%;茶园红壤、紫色土、粗骨土0~20cm、20~40cm土层土壤平均pH值均低于4.5,茶园土壤酸化严重.总体上茶园土壤中交换性Al³⁺的数量和相对比例随交换性酸总量增加而增大,交换性H⁺的相对比例则呈相反的变化特征,交换性Al³⁺占交换性酸的比例为76.67%~98.40%;茶园土壤pH值与交换性酸、H⁺和Al³⁺均呈极显著的负相关关系,相关系数分别为-0.61、-0.46和-0.59.茶园土壤酸碱缓冲性能随着土壤pH值的降低呈现下降趋势;总体上茶园土壤pH值与盐基饱和度呈极显著正相关关系, 土壤pH值与盐基饱和度的正相关主要受到交换性Ca²⁺、Mg²⁺饱和度的制约.但不同土壤类型表现不一,体现了茶园土壤酸度的复杂性、多样性.

Acidic characteristics of subtropical tea garden soil: A case study in Wuyishan city,Fujian province,Southeast China

Based on the data of the 120 layers of 6soil groups which distributed in 60 tea gardens in Wuyishan city in Fujian province, the acidic characteristics of tea garden soils in subtropical China was investigated. The results were as follows: the average soil pH of 0~20cm soil layer was 4.52, and highly acidified soil with pH lower than 4.5 accounted for 55.00% of the total samples. Meanwhile, the average soil pH of 20~40cm soil layer was 4.52, and 53.33% of the samples were lower than 4.5. The average pH of red soils, purple soils, coarse soils in tea garden were all below 4.5in 0~20cm and 20~40cm soil layers. Therefore, high acidification was a serious problem in the majority of tea garden soil in Wuyishan city. Soil exchangeable Al³⁺ and the ratio of exchangeable Al³⁺ against exchangeable acid increased proportionally to the increasing rate of exchangeable acid, while the ratio of exchangeable H⁺ against exchangeable acid has the contrary phenomena. Exchangeable Al³⁺ made up 76.67%~98.40% of exchangeable acid. The pH of tea garden soil has significantly negative correlation with exchangeable acid, exchangeable H⁺ and exchangeable Al³⁺, of which the correlation coefficients were -0.61, -0.46 and -0.59, respectively. The buffering capacity to acid and alkali decreased with the decreasing soil pH. Generally, the soil pH had significantly positive correlation with base saturation, which is mainly controlled by exchangeable Ca²⁺ and Mg²⁺. However, different soil types had different characteristics in terms of their relationships. Therefore, it reflected the complexity and diversity of tea garden soil acidity.