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作 者 ：江长胜1;2;杨剑虹1;魏朝富1;谢德体1;屈明1

期 刊 ：植物营养与肥料学报 2002年 8卷 4期 页码：441-446

关键词：低分子量有机酸；紫色岩；紫色土；钾；

Keywords:low-molecular-weight organic acids, purple rock, purple soil, potassium,

摘 要 ：采用4种浓度为0.05mol/L的低分子量有机酸溶液分别浸提4种紫色母岩风化碎屑和2种紫色土3000h研究其钾的释放规律。结果表明,与纯水浸提相比,0.05mol/L的草酸、酒石酸、柠檬酸以及苹果酸4种低分子量有机酸溶液都能明显促进6种供试样中钾的释放,释放量提高0.3～15.2倍。4种有机酸活化6种供试样中钾的能力以草酸>柠檬酸>酒石酸>苹果酸。侏罗纪沙溪庙组紫色泥岩、沙岩和侏罗纪遂宁组紫色泥岩以及灰棕紫泥4种土壤(或岩样)中钾的释放过程在3000h内用Elovich、双常数、抛物线、一级扩散和双曲线方程等5种动力学方程拟合,结果除一级扩散方程较差外,其它4种方程拟合的相关系数r=0.5988～0.9966(r_0.01=0.6055),以双常数方程拟合效果最佳。拟合方程中常数b值可表征钾的释放速度。

Abstract:The law of potassium release was investigated with four kinds of lowmolecularweight organic acids at 0.05mol/L each extracting four fragments of purple rocks and two purple soils for 3000 hours. The results indicated that lowmolecularweight organic acids could obviously accelerate potassium release from the soils and purple rocks, and the release rates were far quicker than that extracted by pure water under the same conditions, the accumulative amount of potassium release of the former was 0.3～15.2 times larger than that of the latter. The ability of four kinds of organic acids to extract potassium in four soils (or rocks) was in the order of oxalic>citric>tartaric>malic acid. Five common kinetic equations were used to simulate the potassium release in 3000 hours of J₂s and J₃s purple mud rocks and greybrown purple soil. The results showed that all the equations except the onestep diffuse one fit well (r=0.5988～0.9966) with the process of potassium release, and the Double Constant Equation gave the best results. The constant b could be used for estimating the rate of potassium release.

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