添加膨润土对黄绵土有机碳积累的影响  

Effect of Adding Bentonite on Organic Carbon Accumulation in Loess Soil

作　　者：张咏琪 马东豪 谢越 霍亚文[2] 杨熙[2,4] 张佳宝 ZHANG Yongqi;MA Donghao;XIE Yue;HUO Yawen;YANG Xi;ZHANG Jiabao(College of Resources and Environment,Shanxi Agricultural University,Jinzhong,Shanxi 030801,China;Key Laboratory of Soil and Sustainable Agriculture,Chinese Academy of Sciences,Nanjing 211135,China;College of Natural Resources and Environment,Northwest A&F University/Key Laboratory of Green and Low Carbon Agriculture on Dryland in Northwest China,Ministry of Agriculture and Rural Affairs,Yangling,Shaanxi 712100,China;College of Land and Environment,Shenyang Agricultural University,Shenyang 110866,China)

机构地区：[1]山西农业大学资源环境学院,山西晋中030801 [2]土壤与农业可持续发展重点实验室(中国科学院),南京211135 [3]西北农林科技大学资源环境学院/农业农村部西北旱地农业绿色低碳重点实验室,陕西杨凌712100 [4]沈阳农业大学土地与环境学院,沈阳110866

出　　处：《土壤》2024年第5期1018-1026,共9页Soils

基　　金：国家自然科学基金项目(42177292);现代农业产业技术体系专项项目(CARS-03-15,CARS-52)资助。

摘　　要：通过盆栽试验,设置单施有机物料、膨润土与有机物料配施两种处理模式,探究了膨润土添加对黄绵土土壤有机碳积累的影响。结果表明:(1)与CK处理相比,单施有机物料的秸秆还田(S)、施用有机肥(O)、秸秆还田+有机肥配施(SO)、木本泥炭+生物激发剂(WE)处理均可显著提升土壤有机碳含量,增幅分别为14.0%、30.5%、23.9%、30.8%,且在配施0.2%的膨润土(B)后有机碳增加量可进一步提高到14.8%(BS)、35.1%(BO)、26.2%(BSO)、31.8%(BWE);(2)添加膨润土的秸秆还田处理(BS)和秸秆还田+有机肥处理(BSO)较CK处理可以更有效地提高大团聚体(>0.25 mm)的质量分数(增幅分别为7.8%和8.3%),进而提高土壤团聚体平均重量直径(MWD)和几何平均直径(GWD),增强对有机碳的物理保护作用;(3)膨润土添加可以较为明显地提升矿物结合态有机碳(MAOC)含量,B、BS、BO、BSO、BWE处理下MAOC含量较CK、S、O、SO、WE处理分别提升了20.6%、28.2%、9.5%、9.6%、1.4%,且配施有机肥还可以同时提升颗粒态有机碳(POC)含量,其中BO和BSO处理分别比O和SO处理提升了16.9%和11.7%;(4)膨润土的添加可以通过提高土壤矿物结合态碳饱和容量,降低土壤碳饱和亏缺量,提高土壤固碳速率。此外,通过随机森林分析发现,碳酸钙是碱性钙质土壤有机碳饱和亏缺的主要驱动因子,而膨润土的添加有利于缓解碳酸钙对有机质积累的负效应。总之,添加膨润土可以改善土壤结构,促进干旱半干旱地区土壤有机碳的积累。The effects of bentonite addition on accumulation of organic carbon in loessal soil were investigated through a potting experiment,in which two different treatment modes including single application of different organic materials and combined application of bentonite and organic materials were set.The results showed that:1)Compared with CK,straw returned to field(S),application of organic fertilizer(O),combined application of straw+organic fertilizer(SO),and woody peat+bio-stimulant(WE)treatments could significantly increase the soil organic carbon content by 14.0%,30.5%,23.9%and 30.8%,respectively,and the increase of organic carbon could be further increased to 14.8%(BS),35.1%(BO),26.2%(BSO)and 31.8%(BWE)after 0.2%bentonite(B)was applied.2)The bentonite added straw returning to field(BS)treatment and straw returned to field with organic fertilizer(BSO)treatment were more effective than CK treatment in increasing the mass fraction of large aggregates(>0.25 mm)by 7.8%and 8.3%respectively,and thus increasing the mean weight diameter(MWD)and geometric mean diameter(GWD)of soil aggregates,and enhancing the physical protection of organic carbon.3)The addition of bentonite could enhance the content of mineral-associated organic carbon(MAOC),which was 20.6%,28.2%,9.4%,9.6%and 1.4%higher in B,BS,BO,BSO and BWE treatments compared with CK,S,O,SO and WE treatments,respectively.And the content of particulate organic carbon(POC)could be enhanced by the application of organic fertilizer,of which the BO and BSO treatments could enhance the content of particulate organic carbon(POC).The BO and BSO treatments enhanced the POC content by 16.9%and 11.7%over the O and SO treatment,respectively.4)The addition of bentonite could improve the soil carbon sequestration rate by increasing soil mineral binding carbon saturation capacity and reduced soil carbon saturation deficit.In addition,random forest analysis found that calcium carbonate is the main driver of organic carbon saturation deficit in alkaline calcareous soils,and the addit

关 键 词：碱性钙质土 干旱半干旱区 地力提升 土壤有机碳 土壤团聚体 

分 类 号：S156.2[农业科学—土壤学]