不同利用方式对潮棕壤交换性钾钠及盐基总量的影响

Profile Distribution of Exchangeable Potassium, Sodium and Sum of Base Cations in an Aquic Brown Earth as Affected by Land Use

为深刻认识土地利用变化对土壤交换性离子的影响,本文对潮棕壤水稻田、玉米地、撂荒地和人工林地4种土地利用方式经过14年后,在0～150cm剖面中土壤交换性钾、钠、交换性盐基总量的剖面分布及交换性钾钠比值变化进行了比较研究。结果表明,林地和撂荒地各土层交换性K含量及土体中交换性K储量具有高于水稻田和玉米地的趋势;水稻田和撂荒地0～20cm各土层的交换性Na含量显著高于林地和玉米地;林地0～150cm深度土壤交换性Na储量显著高于其他三种利用方式(P<0.05);0～150cm深度内土壤交换性盐基总储量大小依次为林地、玉米地、撂荒地、水稻田;水稻田剖面土壤交换性K/Na随土层深度增加而增大,其他3种土地利用方式则是随土层深度增加而降低。土壤管理和植物自身的特性在土壤剖面中交换性离子的构成以及土壤交换性盐基库的重建等方面可能起到重要作用。

Aimed to further understand the effect of land use pattern on soil exchangeable cations, this study examined the profile variation and storage of soil exchangeable K, Na, the sum of exchangeable base cations, and K/Na ratios at 0-150cm depth of an aquic brown earth under four land use patterns over 14 years. Results showed that soil exchangeable K in each layer and K storage were tended to be higher in woodland and fallow field than in paddy and maize fields. Soil exchangeable Na was significantly higher in paddy and fallow fields than in maize field and woodland in layers of 0-20cm depth. Soil exchangeable Na storage at the depth of 0-150cm was significantly higher in woodland than in the other three land uses （P〈0.05）. The sequence of soil exchangeable base cation storage at the depth of 0 - 150cm was woodland, maize, fallow and paddy fields. The exchangeable K/Na ratio was increased with depth in the profiles of paddy field, but decreased with depth in the other three land uses. Soil management practices and plant characteristics may play an important role in shaping soil exchangeable cation profiles and in reconstructing soil exchangeable base pools.