人工BSCs对稀土尾砂理化性质及抗蚀性的影响

以赣州市定南县岭北镇一座离子型稀土矿尾砂为研究对象,通过采集现场生物土壤结皮与尾砂,采用碎皮接种法在尾砂上培育人工生物土壤结皮(BSCs),以不接种BSCs的尾砂作为对照组,对比分析人工BSCs对离子型稀土矿尾砂的改良作用.在结皮发育300d后,分析了结皮下层尾砂的pH值,容重,有机质含量,全量和速效养分含量,机械组成等基本理化性质,以及土壤侵蚀,土壤径流,保水性能等水文性质.结果表明,碎皮接种法可在短期内快速培育出人工BSCs,且人工BSCs的发育对离子型稀土矿尾砂的理化和水文性质都具有积极影响,与对照相比pH值从5.88提高至6.28,提高了6.8%,土壤酸性减弱;容重降低了11.6%,有机质,全氮,速效氮,全磷,速效磷,全钾,速效钾分别提高了294%,21.6%,81.8%,100%,260%,8.9%和52.4%;粉粒和粘粒的组成有少量提高,土壤被粘化;土壤抗侵蚀能力和保水性能均有显著提高.研究表明适宜的人工生物土壤结皮技术是稀土矿山生态修复的有效选择之一.

The effects of artificial biological soil crusting on the physical and chemical properties and erosion resistance of rare-earth mine tailings

An ionic rare earth mine in Lingbei town, Dingnan county, Ganzhou city, Jiangxi Province, China, were taken as a study object. Biological soil crusts (BSCs) and tailings were collected and artificial BSCs were cultivated using crust-cuttings inoculation method. The effects of BSCs on the ionic rare earth tailings was analyzed by the comparison with a control without BSCs inoculation. After 300days of development of artificial BSCs, the effects of artificial BSCs growth and development on the dynamics of pH, bulk density, organic matter content, total and available content of other nutrients, mechanical composition as well as on soil erosion resistance and water retention capacity of the tailings were explored. The results showed that artificial BSCs could be cultivated in short time by crust-cuttings inoculation method, and improved the physical, chemical, and hydrological properties of the sample tailings, as compared with the control. After 300days of development of artificial BSCs, the SA (soil acidity) was significantly reduced, and the pH increased by 6.8% from 5.88 to 6.28; The SBD (soil bulk density) decreased by 11.6 %, and the OM (organic matter), TN (total nitrogen), AN (available nitrogen), TP (total phosphorus), AP (available phosphorus), TK (total potassium) and AK (available potassium) increased by 294%, 21.6%, 81.8%, 100%, 260%, 8.9% and 52.4%, respectively; The content of silt and clay increased a little; The soil erosion resistance and water retention capacity were both significantly improved. Therefore, artificial biological soil crusting could be an effective method for ecological restoration of ionic rare earth mines.