不同土地利用方式下南亚热带赤红壤酸化特征

土地利用方式是影响土壤酸化的重要因素，研究不同土地利用方式下赤红壤酸化特征可为缓解和治理赤红壤区土壤酸化提供依据。本研究采集了4种土地利用方式(菜地、果园、水田、林地)的赤红壤区土壤样品，测定了表层(0～20 cm)和表下层(20～40cm)土壤的理化性状，结合田间调查和统计数据分析了不同土地利用方式下土壤酸化特征及成因。结果表明：果园表层土壤pH显著低于林地，果园表下层土壤p H显著低于水田和林地；菜地、果园土壤交换性Al³⁺含量显著高于水田和林地；果园表层土壤的盐基饱和度与阳离子交换量均显著低于自然林地，菜地表下层土壤盐基饱和度显著低于水田；与水田和林地相比，菜地和果园的酸化更严重，酸缓冲能力更低。不同土地利用下施肥、复种指数以及耕作方式上的差异可能是造成气候与母质相似地区土壤酸化差异的主要原因。

Acidification Characteristics of Lateritic Red Soil Under Different Land Use Types in Typical Subtropical Region

Abstract: Land use types is an important factor affecting soil acidification. Study on the acidification characteristics and differences of lateritic red soil under different land use types is the premise of mitigating and controlling soil acidification in lateritic red soil region. In this study, we selected four land use types (vegetable lands, orchards, paddy fields, woodlands) of lateritic red soil, by measuring different levels (surface: 0-20 cm, subsurface: 20-40 cm) of soil physical and chemical properties, and combined with field investigation to analyze the acidification characteristics and causes of lateritic red soil under different land use types. The results showed that the pH value of orchards was significantly lower than that of woodlands in the surface layer, and the pH value of orchards was significantly lower than that of paddy fields and woodlands in the subsurface layer. The exchangeable Al3+ content in vegetable lands and orchards was significantly higher than that of paddy fields and woodlands. In the surface layer, the base saturation and CEC of orchards were significantly lower than those of woodlands. In the subsurface layer, the base saturation of paddy fields was significantly higher than that of vegetable lands (p < 0.05). Compared with paddy fields and woodlands, vegetable lands and orchards had more serious acidification and worse acid buffering capacity. Differences in fertilization, multiple cropping index and tillage methods may be responsible for soil acidification under different land uses.