亚热带茶园土壤酸度特征研究--以福建省武夷山市为例

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

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p H值为4.52,其中p H〈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p H值为4.52,p H〈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p H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p H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p H值的降低呈现下降趋势;总体上茶园土壤p H值与盐基饱和度呈极显著正相关关系,土壤p H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.

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 p H of 0~20cm soil layer was 4.52, and highly acidified soil with p H lower than 4.5 accounted for 55.00% of the total samples. Meanwhile, the average soil p H of 20~40cm soil layer was 4.52, and 53.33% of the samples were lower than 4.5. The average p H 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 p H 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 p H. Generally, the soil p H 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.