P. Barré等认为温带地区自然土壤中,由于植物根系将下层土壤中的钾和硅向上搬运,减缓了上层土壤中伊利石类矿物(混层伊利石/蒙皂石+伊利石)脱钾和脱硅过程,致使其长时间地存在较多的伊利石类矿物.本文旨在了解热带地区土壤中这一假设是否也存在,以海南琼北地区发育于由不同年代火山喷发形成的玄武岩所构成的时间序列土壤(1×10~4 a, (9.0±2.0)×10~4 a, (14.6±0. 9)×10~4 a, 64×10~4 a, (133±18)×10~4 a, (181±8)×10~4 a)为对象,利用X-射线衍射(XRD)技术分析了其黏土矿物的变化情况,结合土壤钾、硅、活性硅的分析结果,发现伊利石类矿物仅存在于(133±18)×10~4 a以前的土壤中,表层土壤中钾和硅的含量高于下层的土壤,活性硅含量随成土年龄而降低.为此,我们认为:P. Barré假设在热带土壤形成发育过程中,在具有一定的生物复钾和复硅条件下,在成土初期也会存在,但最终会由于土壤强烈的脱钾和脱硅作用而逐步消失.
CHANGE OF ILLITE-LIKE CLAY MINERALS IN TROPICAL CHRONOSEQUENCE SOILS DERIVED FROM BASALT-DOES P. BARR(E) HYPOTHESES ALSO EXIST IN TROPICAL SOIL?
P. Barré et al. Put forth a hypotheses in 2007 that in soils of the temperate zone plants uplift of potassium and silicon from lower soil horizons buffers K and Si depletion from illite-like minerals (illite and illite/smectite) in the upper soil horizon, thus leading to the long existence of high amount of illite-like minerals. To verify whether the hypothesis exists in soils of the tropical region, chronosequence soil samples were selected from 6 profiles (1×10~4 a, (9.0±2.0)×10~4 a,(14.6±0.9)×10~4 a, 64×10~4 a, (133±18)×10~4 a, (181±8)×10~4 a) derived from Quaternary basalts formed after volcano eruptions in different time periods in Hainan Island, southern tropical China, for analysis of the variation of clay minerals in these soils, using the classical X-ray diffraction technique. Soil potassium, silicon, and active silicon of the samples were also determined. Results show that illite-like minerals existed only in the soils older than (133±18)×10~4 a, where the contents of potassium and silicon were found to be higher in the upper soil horizons than in the lower soil horizons, while a contrary tendency was detected with the content of gibbsite, and the content of active silicon generally decreased with the soil age. Consequently, it is held that during the forming process of the soils of the tropical regions, P. Barré hypotheses might exist in the initial period of soil development, and in the presence of biological complex potassium and complex silicon as well, but it would disappear finally due to the intensive K and Si depletion of the soils in the tropical regions.
国家科技期刊平台
NSTL
万方数据
