目的 探究添加城市污泥对稀土矿废弃地土壤的改良作用，以及在添加污泥基础上添加蔗渣和土壤调理剂的强化效果，以期为稀土矿区土壤改良提供理论依据，也为城市污泥资源化利用提供新思路。方法 以稀土矿区土壤为研究对象，设置3个处理：添加污泥(T1)、添加污泥+蔗渣(T2)、添加污泥+蔗渣+土壤调理剂(T3)，矿区土壤作为对照(CK)，以剑豆Canavalia gladiata为种植材料，通过盆栽试验验证土壤改良效果；测定土壤理化性质和剑豆生长指标，运用主成分分析和模糊隶属函数分析方法综合分析不同处理的土壤改良效果。结果 与对照相比，3种处理均极大地改善了矿区土壤的理化性质，促进了剑豆生长和氮、磷、钾养分元素吸收。其中，T1处理使土壤容重降低27.64%，总孔隙度提高23.91%，毛管持水量提高42.41%，有机质含量提高11.01倍，全磷、碱解氮、速效磷、速效钾含量大幅增加；T2处理的土壤物理性质优于T1，有机质含量提高25.9%，pH提高0.32；T3处理的土壤pH(7.22)最高，较T2提高49.17%，速效磷、速效钾含量分别提高0.46%和11.05%。T2和T3处理植株的总生物量显著高于T1和CK，且T2和T3处理之间无显著差异；单株氮、磷、钾的积累量均在T2处理达到最大值，分别为934.43、172.07、931.35 mg，且与其他处理差异显著。CK、T1、T2、T3的隶属函数平均值分别为0.06、0.56、0.83、0.90，土壤改良效果排序为T3>T2>T1。结论 添加污泥显著改良矿区土壤，在添加污泥基础上加入蔗渣和土壤调理剂的改良效果显著增强。
Objective To study the improvement effect of urban sewage sludge addition on soil of rare earth mine wasteland, and the strengthening effects of adding bagasse and soil conditioner on the basis of sewage sludge, and provide a theoretical guidance for soil improvement of rare earth mining areas and utilization of urban sewage sludge resources.Method The soil of rare earth mine wasteland was selected as research object. Three treatments including adding sewage sludge (T1), adding sewage sludge and bagasse (T2), adding sewage sludge, bagasse and soil conditioner (T3) were set. The soil of rare earth mine wasteland was used as control (CK). Canavalia gladiata was chosen as test material to verify soil improvement effect through pot experiment. The physicochemical properties of testing soil and C. gladiata growth indexes were determined, and the soil improvement effects of different treatments were comprehensively analyzed by principal component analysis and fuzzy membership function analysis.Result Compared with the control, three treatments greatly improved the physicochemical properties of soil in mining area, promoted the growth of C. gladiata and the absorption of N, P and K nutrient elements. T1 reduced soil bulk density by 27.64%, increased total porosity by 23.91%, increased capillary water holding capacity by 42.41%, increased the content of organic matter by 11.01 times, and meanwhile greatly increased the contents of total P, alkaline hydrolytic N, available P and available K. The soil physical properties of T2 were better than those of T1, with organic matter content increased by 25.9% and pH increased by 0.32. The soil pH (7.22) of T3 was the highest, which was 49.17% higher than T2, and the contents of available P and available K increased by 0.46% and 11.05% respectively. The total plant biomasses of T2 and T3 were significantly higher than those of T1 and CK, and there was no significant difference between T2 and T3. The accumulations of N, P and K per plant reached the maximums in T2, which were 934.43, 172.07 and 931.35 mg respectively, and significantly different from other treatments. The average subordinate function values of CK, T1, T2 and T3 were 0.06, 0.56, 0.83, 0.90 respectively, and the soil improvement effects were ranked as T3>T2>T1.Conclusion The addition of urban sewage sludge significantly improves the soil of mining area, and the improvement effect is significantly enhanced by adding bagasse and soil conditioner on the basis of adding sewage sludge.