施用污泥对油菜根际养分和不同种类重金属的影响

发布时间：2018-04-27 05:30

本文选题：根际 + 污泥　；参考：《生态学报》2017年20期

【摘要】：根际是控制植物养分动态的重要因素,养分动态也影响着根际土壤环境。当土壤被污水污泥改良后,根际土壤中的养分和重金属性质也会发生变化。目前很少有人研究施用污泥的土壤中植物根系对根际重金属有效性和分布的影响。采用根垫—冰冻薄层切片法对施用污泥后土壤中油菜根际的养分和重金属分布情况进行研究,以期探明污泥改良土壤中根际重金属的活化特征。当土壤施用污泥后,根际土壤中DTPA提取态Zn,Cd,Ni,Mn,有效磷,有效钾和铵态氮被显著消耗,而根际土壤中DTPA提取态Cu没有明显的消耗或积累。当土壤中施用大量污泥时,根际土壤的pH值随着离根表面距离的增加而增加。无论土壤是否用污泥处理,油菜根际土壤中可交换态Cu都显著减少。当土壤被50%污泥改良时,在距离根表面0—2 mm处的油菜根际土壤中碳酸盐结合态,铁锰氧化物结合态,有机物结合态,残渣态的Cu和Zn都被消耗较多。污泥的施用对油菜的生长有促进作用。随着污泥施用量的增加,油菜地上部分Cu和Zn的含量没有显著变化。施用污泥量小于25%的土壤中,污泥没有增加重金属的可利用性和移动性。除了Cu,油菜根际土壤中DTPA提取态Zn,Cd,Ni的减少表明施用污泥的土壤中重金属的活化是非常有限的。
[Abstract]:Rhizosphere is an important factor to control plant nutrient dynamics, and nutrient dynamics also affect rhizosphere soil environment. When the soil was improved by sewage sludge, the properties of nutrients and heavy metals in rhizosphere soil also changed. The effects of plant roots on the availability and distribution of heavy metals in the rhizosphere were rarely studied. The distribution of nutrients and heavy metals in soil rhizosphere after application of sludge was studied by the method of root cushion and frozen thin-layer slicing in order to find out the activated characteristics of heavy metals in the rhizosphere of soil improved by sludge. When sludge was applied to the rhizosphere soil, the available phosphorus, available potassium and ammonium nitrogen were significantly consumed by the DTPA extractable form of DTPA in the rhizosphere soil, but no significant consumption or accumulation of DTPA extracted Cu was observed in the rhizosphere soil. When a large amount of sludge was applied to the soil, the pH value of the rhizosphere soil increased with the increase of the distance from the root surface. No matter whether the soil was treated with sludge or not, the exchangeable Cu in rapeseed rhizosphere soil decreased significantly. When the soil was improved by 50% sludge, the carbonate-bound, iron-manganese oxide, organic-bound and residual Cu and Zn in rape rhizosphere soil 0-2 mm from the root surface were consumed. The application of sludge can promote the growth of rapeseed. The content of Cu and Zn in the aboveground part of rapeseed did not change significantly with the increase of sludge application rate. Application of sludge less than 25% of soil sludge did not increase the availability and mobility of heavy metals. In addition to Cu, the reduction of DTPA extractable Zn ~ (2 +) ~ (2 +) ~ (2 +) in rapeseed rhizosphere indicated that the activation of heavy metals in sludge application soil was very limited.
【作者单位】：天津师范大学天津市水环境与水资源重点实验室;
【基金】：国家自然科学基金项目(40940010,40973078) 天津市水资源与水环境重点实验室开放基金
【分类号】：S141.6;S565.4

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