周期性淹水-落干和施用秸秆对白云石改良棕壤磷素流失风险的模拟研究  

Simulation Study on Phosphorus Loss Risk with Periodic Flooding-Drying and Straw Incorporation in a Dolomite-Amended Brown Soil

作　　者：范贝贝 丁帅 张田田 张帅[1,3] 魏露露 陈清 FAN Beibie;DING Shuai;ZHANG Tiantian;ZHANG Shuai;WEI Lulu;CHEN Qing(Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation,College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,P.R.China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,P.R.China;Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences,Beijing 100081,P.R.China)

机构地区：[1]中国农业大学农田土壤污染防控与修复北京市重点实验室/资源与环境学院,北京100193 [2]中国科学院南京土壤研究所,江苏南京210008 [3]中国农业科学院农业资源与农业区划研究所,北京100081

出　　处：《生态环境学报》2024年第8期1203-1213,共11页Ecology and Environmental Sciences

基　　金：国家重点研发计划(2023YFE0104700);现代农业产业技术体系专项(CARS-23-B15)。

摘　　要：农田土壤磷累积及潜在的磷素流失风险在中国受到广泛的关注。施用白云石是降低土壤磷流失风险的有效措施之一,但常见农田管理措施(秸秆还田、交替灌溉以及它们的组合措施等)如何影响白云石改良后土壤的磷素流失风险及其相关机制目前还不清楚。采用培养试验,探究施用秸秆、周期性淹水-落干、周期性淹水-落干和施用秸秆联合处理对白云石改良土壤活性磷含量、磷吸附/解吸特性、连续浸提磷组分和土壤理化性质的影响。结果表明:与仅施用白云石的对照(CK)相比,施用秸秆(S)和周期性淹水-落干处理(FW)使土壤不稳定磷(CaCl_(2)-P)分别增加62.3%和15.9%;并同时降低土壤磷最大吸附容量(6.26%-12.5%)和Na HCO_(3)-P_(i)(6.97%-19.2%)。秸秆本身含有的磷和易解吸态磷(Na HCO_(3)-P_(i))的释放分别是上述处理土壤活性磷增加的主要原因。周期性淹水-落干和施用秸秆联合处理(FWS)使土壤CaCl_(2)-P和Bray-P分别降低43.4%和23.2%。这一处理也显著提高了土壤非晶质铁质量分数(21.6%),增强土壤对磷的吸附,并抑制吸附态磷的解吸,进而降低土壤活性磷质量分数。此外,周期性淹水-落干和施用秸秆联合处理也显著提高了土壤Fe^(2+)(423%)和铁活化度(18.8%),促进了土壤Fe/Al-P向稳定态磷转化,使HCl-P增加26.9%。土壤磷吸附能力的提高、非晶质铁对活性磷的固定和稳定态磷(HCl-P)质量分数的增加是周期性淹水-落干和施用秸秆联合处理中磷流失风险降低的重要原因。结构方程模型表明,土壤非晶质铁和有机质是影响磷素流失的关键因素。研究表明,适当的淹水-落干措施配合秸秆还田能增强白云石改良土壤中磷素的固持,降低磷素流失风险,可为胶东半岛高磷土壤的管理提供科学依据。The accumulation of phosphorus (P) in farmland soils and the potential risk of P loss have been widely studied in China.The application of dolomite is an effective measure for reducing the risk of P loss in soil.However,it is unclear how common field management measures (straw incorporation,alternative irrigation,and their combination) affect the risk of P loss in dolomite-amended soils and the related mechanisms.This study investigated the changes in active P content,P adsorption/desorption characteristics,continuous P extraction components,and soil physicochemical properties subjected to periodic flooding-drying,straw incorporation,and coupling of periodic flooding-drying and straw incorporation by a culture experiment.The results showed that the mass fraction of CaCl2-P in the soil increased by 62.3%and 15.9%with straw incorporation (S) and periodic flooding-drying (FW) treatments,respectively,compared to dolomite treatment (CK).In addition,the maximum phosphorus adsorption capacity and NaHCO3-Pi decreased by 6.26%-12.5%and 6.97%-19.2%in the straw incorporation and periodic flooding-drying treatments,respectively.The P contained in the straw and release of easily desorbed P (NaHCO3-Pi) caused an increase in active P in the treated soil.The coupling of periodic flooding-drying and straw incorporation (FWS) reduced soil CaCl2-P and available P (Bray-P) by 43.4%and 23.2%,respectively.The treatment significantly increased poorly crystalline Fe (21.6%),enhanced P adsorption,and inhibited the desorption of adsorbed P,thereby reducing the mass fraction of active P in soil.In addition,the coupling of periodic flooding-drying and straw incorporation significantly increased Fe^(2+)(423%) and iron activation (18.8%),promoting the conversion of soil Fe/Al-P to stable P,thus increasing the HCl-P by 26.9%.The increase in soil P adsorption capacity,the increased adsorption of poorly crystalline Fe to active P,and the increase in stable P (HCl-P) mass fraction were the important reasons for the reduction of P loss risk in the

关 键 词：高磷土壤 白云石 秸秆还田 淹水-落干 土壤磷流失 

分 类 号：S153[农业科学—土壤学] X144[农业科学—农业基础科学]