Abstract：
This study was conducted to assess the potential of river sediment for amendment of agricultural land with respect to heavy metal mobilization. The mobility and concentration of bioavailable heavy metal containing in the sediment were evaluated with the use of DTPA (diethylenetriamine pentaacetic acid) extraction techniques. Sum of metals in exchangeable and carbonate fractions obtained from sequential extraction scheme was used to evaluate the potential plant available. Four land blocks of size (1 m × 5.8 m) were prepared for cabbage field experiment and applied with different loading rates of sediment (≈28 and 42 ton/ha or equivalent to 100 kgN/ha and 150 kgN/ha). In parallel test, land blocks treated with fertilizer at similar nitrogen loading rates were also conducted for comparisons. Pure soil plot was used as a control system. Results show that both plant available and total heavy metal concentration were found higher in those plots treated with higher loading rates of sediment (42 ton/ha). The concentrations of heavy metals (Cu,Zn,Pb) in soil were decreased with time after crop harvesting and the residues remain in the soil were well below those of the UK, USA and Germany standards. Simple linear regression was used to show the correlation between the DTPA extractable metals and the plant metals fractions (root and shoot) resulting from fertilizer and sediment applications in the amended soils. In most cases, plant available metal concentrations showed positively correlated with plant metal uptake concentrations (R 2 = 0.01-0.95, n = 3). Concentration of metals in the cabbage tissue detected: Zn at 131.53 ± 10.43 mg kg-1 DM, Cu at 20.84 ± 1.62 mg kg-1 DM, Pb at 0.09 ± 0.01 mg kg-1 DM, Cd at 0.21 ± 0.09 mg kg-1 DM and Ni at 0.44 ± 0.05 mg kg-1 DM. None of these metals concentration exceeded the tolerable limits of plant. One-way analysis of variance (ANOVA) was applied to find out the effect of different soil amendments on cabbage yield in term of fresh and dry weights. The sequence of crop yields in this field studies for amended soils is chemical fertilizer>sediment>control soil.
摘要：
进行这项研究是为了评估河流沉积物在重金属动员方面对农业用地进行改良的潜力。使用DTPA（二亚乙基三胺五乙酸）萃取技术评估了沉积物中生物可利用的重金属的迁移率和浓度。从顺序提取方案中获得的可交换和碳酸盐馏分中的金属总和用于评估潜在的可用植物。为白菜田间试验准备了四个大小（1m×5.8m）的土地块，并施加了不同的沉积物负荷率（≈28和42吨/公顷或相当于100kgN/公顷和150kgN/公顷）。在并行测试中，还进行了以相似的氮负荷率进行肥料处理的地块进行比较。纯土地块用作控制系统。结果表明，在用较高的沉积物负荷率（42吨/公顷）处理的地块中，植物有效和总重金属浓度均较高。重金属的浓度(Cu，Zn,作物收获后，土壤中的Pb）随着时间的流逝而减少，残留在土壤中的残留物远低于英国的残留物，美国和德国的标准。使用简单的线性回归来显示DTPA可提取金属与改良土壤中肥料和沉积物施用产生的植物金属组分（根和芽）之间的相关性。在大多数情况下,植物有效金属浓度与植物金属吸收浓度呈正相关（R2=0.01-0.95，n=3）。检测到的白菜组织中金属的浓度：Zn为131.53±10.43mgkg-1DM，铜在20.84±1.62mgkg-1DM，铅在0.09±0.01mgkg-1DM，Cd为0.21±0.09mgkg-1DM，Ni为0.44±0.05mgkg-1DM。这些金属的浓度均未超过植物的容许极限。应用单向方差分析（ANOVA），以确定不同土壤改良剂对白菜鲜重和干重的影响。在该田间研究中，改良土壤的作物产量顺序为化肥>沉积物>对照土壤。
