橡胶树人工林地土壤酸度特征及酸化原因分析

以玄武岩发育的砖红壤地带橡胶树人工林地为研究对象，通过测定土壤交换性酸、交换性盐基离子组成和土壤的pH,探究橡胶树人工林地土壤酸化特征以及土壤pH与潜性酸、交换性盐基之间的关系。结果表明:橡胶树人工林地土壤pH范围在4.97~5.77，二代胶园表层土壤pH略高于裸地和一代胶园；交换性铝在交换性酸中所占的比例随交换性酸总量增加而增加，相关系数达到0.987 7，而有机质对交换性酸度影响较小；供试土壤中对应土层的盐基总量大小依次为:裸地土壤＞二代胶园＞一代胶园，二代胶园中交换性钙的饱和度高于其他盐基离子，而一代胶园中交换性镁占优势；土壤pH与交换性酸度呈极显著正相关性,与盐基总量呈负相关，且主要受交换性钠和交换性镁的影响。交换性铝是橡胶园酸性土壤酸度的主要贡献者，Na⁺和Mg⁺盐基离子淋失是加速胶园土壤酸化的一个重要影响因素。

Characteristics and Causes of Soil Acidification in the Rubber Plantation

In this aticle,ferruginous laterites derived from basalt in rubber tree plantations were used as research objetc to study the relationship between the rubber tree plantation soil acidification characteristics and active acidity and latent acid,exchangeable base by measuring the soil exchangeable acid,pH and exchangeable cation composition in the soil.Soil pH of rubber plantation ranged from 4.97 to 5.77, the pH of the surface soil in second generation of rubber plantations was slightly higher than that in the open field and the first generation plantation.The proportion of exchangeable aluminum in exchangeable acid (EA) increased with the increase of EA,with the correlation coefficient of 0.987 7 h.Wile organic matter exhibited little influence on EA.The total base in corresponding soil layers was in the order of open field > the second generation rubber plantation > the first generation rubber plantation.The degree of saturation of exchangeable calcium was higher than other cations in the second generation plantation.While in the first generation plantation,exchangeable magnesium was the dominant cation.Soil pH was very significantly and positively correlated with exchangeable acidity,and negatively correlated with total base,and was mainly affected by the exchangeable sodium and exchangeable magnesium.Exchangeable aluminum was the major contributor for soil acidity,leaching loss of sodium and magnesium was the key factor for the acidification of rubber plantation.