HYSTERESIS EFFECTS IN SOIL MOISTURE MOVEMENT
[摘要] HysteresiswasassessedbymeasuringthetensionandmoisturecontentofsectionsofsoilatdifferenttimeintervalsduringtheredistributionofmoistureinuniformlypackedcolumnsofGrenvillesiltloam.Moisturetensionwasmeasuredbyanullmethodandmoisturecontentwasmeasuredgravimetrically.Therateofchangeoftensionwithmoisturecontentdψ/dθandhencethediffusivity,inthetensionrange25to400centimetersofwaterwasmorethantwiceasgreatfordryingasforwetting.Duringredistributionofmoisture,whenbothdryingandwettingwereinvolved,differentψ,vs.θrelationshipsexistedatdifferentdepths,andtheslopesdψ/dθanddiffusivitiesintheprofilewereoftenlowerthanthoseforeitherdryingorwettingalone.Furtherworkisneededtoassesstheimportanceofhysteresisonmoisturemovementinpracticalproblems.Itseemspossiblethatdataonhysteresis,andaknowledgeofthepasthistoryofwettinganddrying,mayprovideestimatesofmoisturelossandconservation...
[发布日期] [发布机构]
[效力级别] [学科分类] 农业科学（综合）
[关键词] [时效性]
