典型酸雨地区森林土壤中不同形态铝的分析

Analysis of Different Formed Aluminum in Forest Soil at Typical Acid Rain Areas

对2个典型酸雨地区森林土壤样品中不同形态的铝进行了检测,结果表明:两地土壤中无定形铝和有机结合铝占主导地位,弱有机结合铝和可交换铝的含量相对较低(约为10%)。有机配位体会减弱铝的交换能力,而且这些有机铝配合物大部分是强有机结合态铝;Al3+对其他碱基阳离子有较强的置换能力。土壤的酸度增大,可交换铝和弱有机结合铝的含量增高,不同土层中可交换铝和弱有机结合铝的垂直变化与相应的pH变化相一致。用复合草酸铵法提取无定形和有机态铝的方法机理尚待进一步研究。

The different formed aluminum in forest soil at two typical acid rain areas were detected.It is shown that the amount of amorphous aluminum and organically bound aluminum are high in both areas,the amount of exchangeable aluminum and weakly organically bound aluminum are relatively low; the exchange ability of aluminum can be weakened by organic ligand;and Al^(3+) has strong displacement ability to other base cations.The stronger the acidity of soil is,the more the contents of exchangeable aluminum and weakly organically bound aluminum are.The vertical change of exchangeable aluminum and weakly organically bound aluminum in different horizons of soil is in keeping with the change of pH.The method mechanism of oxalate-extractable aluminum needs to be further studied.