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选取菜子湖区不同退耕年限(3、5、7、9、11和21 a)湿地、以仍耕油菜地和原始湿地土壤为研究对照,分析了土壤全铝和活性铝形态组分特征,探讨退耕还湖后湿地土壤铝元素组分特征变化及其生态效应。结果表明,研究区土壤全铝含量和活性铝含量分别在16.78~57.05 g/kg和1 699.94~3 823.49 mg/kg之间,其中活性铝总量占全铝含量的6.70%~11.84%。退耕还湖3~11a期间,土壤全铝、活性铝总量及5种形态活性铝总体均随退耕年限延长而增加;退耕11~21 a期间均下降。不同形态活性铝中,可溶性铝Al S含量最低,而酸溶无机铝和腐殖酸铝Al-HA含量较高,分别占活性铝总量的42%~53%和39%~50%,左右着活性铝总量的变化。分析讨论表明退耕后湿地植被和水文条件的改变导致土壤粘粒,有效磷和有机质的变化,进而影响退耕后土壤活性铝组分特征。其中0~5 cm土壤毒性较强的交换性铝Al3+和羟基铝Al(OH)2+、含量均在退耕3~9 a期间逐渐增加,占活性铝总量的比例也有所增加,该退耕期湿地土壤存在一定的铝毒生态风险。
In order to compare the characteristics of the form components of all-aluminum and active aluminum in soils, and to study the effects of different returning-farm years (3, 5, 7, 9, 11 and 21 a) Changes of Al Element Compositions and Their Ecological Effects in the Wetland Soils after Wetlands. The results showed that the total aluminum content and the active aluminum content of the soil were between 16.78 and 57.05 g / kg and between 1 699.94 and 3823.49 mg / kg, respectively, and the total amount of active aluminum accounted for 6.70% ~ 11.84% of the total aluminum content. During the period of returning farmland to lake 3 ~ 11a, the total amount of all-aluminum, total amount of active aluminum and five forms of active aluminum increased with the extension of the retirement period; The content of soluble Al in the different forms of active aluminum is the lowest, while the content of Al-HA in acid-soluble inorganic aluminum and humic aluminum is higher, accounting for 42% -53% and 39% -50% of the total amount of active aluminum, respectively Changes in the total amount of active aluminum. The analysis and discussion showed that the changes of wetland vegetation and hydrological conditions resulted in the changes of soil clay, available phosphorus and organic matter, and then the characteristics of soil active aluminum components after returning farmland. Among them, the content of exchangeable aluminum Al3 + and Al (OH) 2 Al in soil with 0 ~ 5 cm soil toxicity increased gradually during the period of 3 ~ 9 a after returning farmland, and the proportion of the total amount of active aluminum also increased. Wetland soil has some aluminum toxicity ecological risk.