肥田萝卜、油菜对金云母中矿物钾的活化与利用

MOBILIZATION AND UTILIZATION OF STRUCTURAL POTASSIUM IN PHLOGOPITE AS AFFECTED BY PLANT SPECIES

本试验以金云母作为植物的唯一钾源,研究了缺磷与正常供磷条件下肥田萝卜、油菜对矿物结构钾的利用。结果表明,缺磷条件下两种植物每盆的吸钾总量( 肥田萝卜14-96mg ,油菜12-88mg) 以及矿物钾的净释放量( 肥田萝卜6-22mg ,油菜4-32mg) 均显著高于正常供磷处理的植物吸钾总量( 肥田萝卜11-90mg,油菜9-57mg) 和矿物钾净释放量( 肥田萝卜3-72mg,油菜3-07mg) 。同时,对根际金云母进行X光衍射扫描,结果发现两种处理的肥田萝卜和油菜的根际金云母均出现了明显的蛭石化现象,其中缺磷条件下两种植物引起的蛭石化作用较正常供磷的处理更显著。

The weathering of a tricotahedral mica (phlogopite, <0.25mm particle size) was investigated in the rhizophere of radish and pak choi. When phlogopite was the sole source of K for the plants under P?deficiency, total K uptake of both plants were significantly higher than that in the normal P conditions, 14 96mg·pot -1 versus 11 90mg·pot -1 for radish and 12 88mg·pot -1 versus 9 57mg·pot -1 for pak?choi, and corresponding numbers for net release of mineral K were 6 22mg·pot -1 versus 3 72mg·pot -1 for radish and 4 32mg·pot -1 versus 3 07mg·pot -1 for pak choi. The X?diffractometry showed a strong vermiculitization of the phlogopite. In contrast to the normal growth conditions, the degree of vermiculitization was much stronger induced by two species under P deficiency. That suggests that P?starvation led to a significant increase in the amount of K released from mineral K pool. The enhanced mobilization of mineral K might be attributed to the release of organic acids from the plant roots.