Increase in cation exchange capacity by the action of maize rhizosphere on Mg or Fe biotite-rich rocks

ABSTRACT The weathering of some silicate minerals in crushed rocks may occur in a few days of cropping and generate different physicochemical properties, with potential benefits to tropical soils. This study aimed to investigate the infuence of maize (Zea mays L.) rhizosphere on the weathering products and on the cation exchange capacity of Mg-biotite from biotite schist and Fe-biotite from biotite syenite. An experiment was carried out in pots, so that plants and crushed rock materials could be evaluated during seven successive growth cycles. The nutrients iron and potassium were taken up from biotite schist and biotite syenite during cropping. The weathering of both biotites promoted by the rhizosphere caused mineralogical changes. The most expressive change in the X-ray diffraction patterns occurred in the摘要 粉碎岩石中的部分硅酸盐矿物可在数天的种植周期内发生风化作用，生成多种理化特性，对热带土壤具有潜在益处。本研究旨在探究玉米（Zea mays L.）根际（rhizosphere）对黑云母片岩中Mg-黑云母（Mg-biotite）以及黑云母正长岩中Fe-黑云母（Fe-biotite）的风化产物与阳离子交换量（cation exchange capacity）的影响。本研究设置盆栽实验，以便在7个连续种植周期内对植株与粉碎岩石材料开展评估。种植期间，植株可从黑云母片岩与黑云母正长岩中吸收铁与钾养分。根际环境促发的两种黑云母风化作用均引发了矿物学层面的变化。X射线衍射（X-ray diffraction）图谱中变化最为显著的部分出现在