两性磁化炭对牧草生长及土壤铜有效性的影响

Effects of Adding Amphoteric Magnetized Carbon on Forage Growth and Soil Copper Availability

为了探究材料添加对植物修复过程中的牧草生长和土壤铜有效性特征的影响,采用盆栽试验研究7种土壤Cu2+污染水平[0,100,200,400,800,1200,1600 mg/L]下,两性磁化炭表施(0-3 cm)和混施对苏丹草(Sorghum sudanense(Piper)Stapf.)和黑麦草(Lolium multiflorum L.)发芽率、株高和生物量的影响,并分析了盆栽土壤中水溶态和酸提取态铜含量的变化特征。结果表明:(1)在未经Cu2+处理时,表施和混施两性磁化炭都能大幅度提高黑麦草的发芽率和成活率;Cu2+处理后,表施两性磁化炭有利于苏丹草的发芽,但不利于其成活,混施能够提高苏丹草在Cu2+浓度400~800 mg/L内的成活率;(2)各土样上的苏丹草和黑麦草株高前期增长迅速(2 cm/d左右),25 d后趋于缓和。单施两性磁化炭更有利于黑麦草的生长,其中表施的作用尤为显著。(3)混施两性磁化炭能增加苏丹草在Cu2+400~800 mg/L区间中的生物量,而Cu2+浓度低于200 mg/L时,表施和混施两性磁化炭都有利于两种牧草生长;(4)土壤水溶态Cu2+含量和酸提取态Cu2+含量均保持上层高于下层的趋势,黑麦草降低土壤中Cu2+含量的能力强于苏丹草。综上,在铜污染地区表施两性磁化炭并种植黑麦草对土壤的修复效果最佳。

In order to explore the effects of material addition on forage growth and soil copper availability during phytoremediation, potting experiments were conducted to study the effects of surface application(0-3 cm) and mixed application of amphoteric magnetized carbon on the germination rate, plant height and biomass of sudan grass[Sorghum sudanense(Piper) Stapf.]and ryegrass(Lolium perenne L.) under different Cu2 pollution levels [0, 100, 200, 400, 800, 1 200 and 1 600 mg/L], and the variation characteristics of copper content in water-soluble state and acid extracted state of of different soil layers were analyzed. The results showed that:(1) the germination rate and survival rate of ryegrass could be improved by both surface and mixed application of amphoteric magnetized carbon without Cu2+ in soil;after Cu2+ treatment, surface application of amphoteric magnetized carbon enhanced the germination of sudan grass, but was not beneficial to its survival;mixed application of amphoteric magnetized carbon could improve the survival rate of sudan grass under 400~800 mg/L Cu2+ treatment;(2) the height of sudan grass and ryegrass rapidly increased in the early growth stage(about 2 cm/d), and tended to moderate in the remaining stages(after 25 d);application of amphoteric magnetized carbon was more beneficial to the growth of ryegrass, especially by surface application;(3) mixed application of amphoteric magnetized carbon could improve the biomass of sudan grass under 400~800 mg/L Cu2+ treatment;when the concentration of Cu2+ was less than 200 mg/L, both surface and mixed application of amphoteric magnetized carbon were favorable for the growth of two herbage species;(4) Cu2+ contents in water-soluble state and acid-extracted state all maintained the trend that the contents of upper soil layer was higher than those of the subsoil layer, and ryegrass was more capable of reducing the Cu2+ content in soil than Sudan grass. In conclusion, surface application of amphoteric magnetized carbon and planting ryegrass in copper-polluted areas had the best effect on soil remediation.