纳米矿物水铝英石提升土壤团聚体稳定性的效应  

Effect of Nano-mineral Allophane on Soil Aggregate Stability

作　　者：郑延云 余正洪 张丛志[1] 张佳宝[1] ZHENG Yan-yun;YU Zheng-hong;ZHANG Cong-zhi;ZHANG Jia-bao(Institute of Soil Science,Chinese Academy of Science,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Agricultural Sciences Engineering,Hohai University,Nanjing 211100,China)

机构地区：[1]中国科学院南京土壤研究所,江苏南京210098 [2]中国科学院大学,北京100049 [3]河海大学农业科学与工程学院,江苏南京211100

出　　处：《土壤通报》2025年第1期127-135,共9页Chinese Journal of Soil Science

基　　金：国家重点研发计划项目(2022YFD1500903,2022YFD1500502);安徽省重点研发计划项目(2023n06020056);江苏省自然科学基金(BK20200507)。

摘　　要：【目的】探究纳米矿物水铝英石基于正、负反号双电层重叠作用提升土壤团聚体稳定性的效应。【方法】以江苏省宁镇扬低山丘陵区广泛分布的黄棕壤为研究对象,以水热合成法获得的纳米矿物水铝英石为供试材料,研究不同添加量水铝英石(0 wt.%、0.1 wt.%、0.5 wt.%、1 wt.%)对土壤表面电荷量、zeta电位以及水稳性团聚体的影响。【结果】水铝英石的等电点可达9.2,在黄棕壤中能携带120 mmol kg^(-1)正电荷。添加水铝英石显著降低了土壤净负电荷量,导致土壤胶体zeta电位向正值移动,且添加量越大,净负电荷越少而zeta电位越接近正值方向,表明添加水铝英石后土壤存在明显的正、负反号双电层重叠作用。同时,添加水铝英石显著增加了土壤>2 mm和0.25~2 mm大团聚体的数量、平均重量直径(MWD)、几何平均重量质量(GWD)和大团聚体质量百分含量(R0.25)。土壤大团聚体数量、MWD、GWD和R0.25与zeta电位和表面电荷量呈显著(P<0.05)正相关。【结论】具有高等电点的纳米矿物水铝英石通过正、负反号双电层重叠作用显著增强土壤团聚体的稳定性,在低产土壤结构提升和退化土壤水土保持中具有良好的应用前景。[Objective]This paper investigated the effect of nano-mineral allophane on soil aggregate stability through the overlapping of positive and negative double electric layers.[Method]Yellow-brown earth was collected from the hilly region of Ningzhengyang,Jiangsu Province,and the nano-mineral allophane was synthesized using the hydrothermal synthesis method.The influences of varying amount of allophane(0,0.1 wt.%,0.5 wt.%and 1wt.%)on the soil surface charge number,zeta potential,and water-stable aggregates were evaluated to explore the effect and mechanism of nano-mineral allophane on soil aggregate stability.[Result]The isoelectric point(IEP)of the allophane was approximately 9.2,allowing it to carry more than 120 mmol kg^(-1)positive charges in the yellow-brown soil,resulting in the coexistence of positively and negatively charged electrical double layers(EDLs)after application of allophane.The addition of allophane led to a significant reduction in net negative charges,resulting in a shift towards net positive charge,as evidenced by the gradual increase in zeta potential.Furthermore,the application of allophane substantially increased the mass percentage of large(>2 mm)and small(2-0.25 mm)macroaggregates,as well as the mean weight diameter(MWD),geometric mean diameter(GMD)and mass percentage of macroaggregates(>0.25 mm,denoted as R0.25).Correlation analysis revealed positive relationships between the mass percentages of large and small macroaggregates,MWD,GMD and R0.25,and zeta potential,as well as surface charge number.[Conclusion]The addition of nano-mineral allophane proves to be an effective approach to improve soil aggregate stability through the overlapping of oppositely charged EDLs.The results highlights the potential of nano-mineral allophane as a promising amendment for the middle-low yield cultivated land or newly reclaimed soils.

关 键 词：土壤结构 土壤表面电荷性质 ZETA电位 正、负反号扩散双电层重叠作用 

分 类 号：S156.2[农业科学—土壤学]