简介：Thiscontributionanalyzesthesimilaritiesanddifferencesbetweenthemeasuredactivitiesof137Csandexcess210Pb(210Pbex)inthecultivatedbrownandcinnamonsoilsoftheYimengMountainarea,discussestheinfluenceofsoiltextureonthemeasurementof210Pbex,andpresentsdifferencesbetweenthetwotypesofsoils.FieldsAandBwereselectedtorepresentthefieldsthatcontaincultivatedbrownandcinnamonsoils,respectively.Fromeitherstudyfield,onesiteofsectionedcoreandsixbulkcoreswerecollectedtomeasure137Cslevels,210Pbexlevels,andtheparticle-sizecompositionofsoilsamples.Threeundisturbedsoilsampleswerecollectedtomeasurecapillaryandaerationporosities.The137Csinventoriesforthetwostudyfieldsareverysimilar.The137Csisaman-maderadionuclide,whichmeansthatitsmeasuredlevelsforsoilsareunaffectedbysoiltexture.Incontrast,levelsofthenaturallyoccurring210PbexofsoilsfromFieldAwerelowerthanthoseofFieldBbyabout50%.Incontrasttoaquaticsediments,levelsof210Pbexinterrestrialsurfacesoilsareaffectedbytheemanationof222Rnfromthesoils.Itcanbeassumedthatthecoarserthesoils,thegreatertheemanationof222Rn;inaddition,thelowerthemeasured210Pbex,thegreatertheunderestimateofthisvalue.ThecultivatedbrownsoilsinFieldAarecoarserthanthecultivatedcinnamonsoilsinFieldB.Asaresult,222RninFieldAwilldiffusemoreeasilyintotheatmospherethanthatinFieldB.Asaconsequence,themeasured210PbexinsoilsfromFieldAismuchlowerthantheactualvalue,whereasthevaluemeasuredforFieldBismuchclosertotheactualvalue.

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