生物炭对侵蚀黑土团聚体的影响

Effects of Biochar on Soil Aggregation of Eroded Mollisols

[目的]探讨生物炭对侵蚀黑土团聚体的修复效果,揭示生物炭对侵蚀黑土团聚体的影响机制,为修复侵蚀黑土提供科学依据。[方法]以侵蚀黑土为研究对象,研究未剥离农田(CK)、未剥离农田施生物炭(CK+BC)、模拟侵蚀土壤(RS)、侵蚀土壤施生物炭(RS+BC)4个处理生物炭对黑土团聚体的影响。[结果]与CK处理相比,CK+BC处理中0.25~2 mm粒级团聚体含量增加了14.01%,RS+BC处理中0.25~2 mm粒级团聚体含量比RS处理增加了12.11%,生物炭提高了团聚体的几何平均直径(GMD)和大于0.25 mm团聚体含量,增加了CK+BC和RS+BC两个处理的原土和>0.25 mm粒级团聚体中的土壤有机碳含量(SOC),GMD分别与SOC和交换性钠呈正相关和负相关,且SOC对团聚体的胶结作用大于交换性钠的分散作用,提高了侵蚀黑土团聚体稳定性。[结论]生物炭改善黑土侵蚀后的结构,促进了土壤团聚化,对侵蚀土壤具有良好的修复作用,是修复侵蚀黑土的有效措施。

[Objective]The remediation effects of biochar on eroded mollisols aggregates,define the influence mechanism of biochar on eroded mollisols aggregates were determined in order to provide a scientific basis for remediation of eroded mollisols.[Methods]Four experimental treatments were imposed to determine the effects of biochar on aggregates of an eroded mollisols:uneroded farmland as the control treatment(CK);uneroded farmland with biochar application(CK+BC);simulated eroded soil(RS);and biochar added to eroded soil(RS+BC).[Results]Biochar application increased the content of 0.25~2 mm size aggregates by 14.01%in CK+BC compared with CK.The content of 0.25~2 mm size aggregates in RS+BC treatment increased by 12.11%compared with RS.In addition,biochar increased the geometric mean diameter(GMD)and the contents of macro-aggregates(R 0.25),and the concentration of soil organic carbon(SOC)in bulk soil and aggregates larger than 0.25 mm.These results indicated that biochar improved the SOC content by increasing its macro-aggregates.GMD was positively and negatively correlated with the concentrations of SOC and exchangeable sodium,respectively.However,the function of SOC in aggregation was larger than function of exchangeable sodium in dispersion,resulting in improved aggregate stability.[Conclusion]Biochar improves the structure of eroded mollisols,promotes soil aggregation,and has a good remediation effect on the eroded soil,and is therefore an effective strategy to remediate eroded soil.