Wang_2010

Carbon (C)sequestrationthroughirrigationmanagementisapotentialstrategytoreduceCemissions from agriculture.Twoexperiments(Exps.IandII)wereconductedtoinvestigatetheeffectsofdifferent irrigation strategiesonCretentioninthesoil–plantsysteminordertoevaluatetheirenvironmental impacts. Tomatoplants(Lycopersicon esculentum L., var.Cedrico)weregrowninsplit-rootpotsina climate-controlled glasshouseandweresubjectedtofullirrigation(FI),deficitirrigation(DI)andalter- nate partialroot-zoneirrigation(PRI)atearlyfruitingstage.InExp.I,eachplantreceived2.0gchemical nitrogen (N),whileinExp.II,1.6gchemicalNandmaizeresiduecontaining0.4gorganicNwereapplied into thepot.Theresultsshowedthat,inbothexperiments,theconcentrationandtheamountoftotalCin the soilwerelowerinFIandPRIascomparedtoDI,presumablyduetoagreatermicrobialactivityinthe two treatments;particularlythePRIinduceddryingandwettingcyclesofthesoilsmaycauseanincrease of microbialactivitiesandrespirationrate,whichcouldleadtomoreClossesfromthesoil.However,in both experimentsthetotalCconcentrationinthePRIplantswasthehighestascomparedwiththeFI and DIplants,andthiswasseeminglyduetoimprovedplantNnutritionunderthePRItreatment.Con- sequently, thetotalamountofCretainedinthesoil–plantsystemwashighestintheFIandwassimilar, but lower,forthePRIandDI.ThedifferentNinputinthetwoexperimentsmighthaveaffectedtheC retention inthesoilandintheplantbiomass.Nevertheless,withasamedegreeofwatersaving,PRIwas superior toDIintermsofenhancingCconcentrationintheplantbiomass,whichmighthavecontributed to abetterfruitqualityintomatoesasreportedby Zegbe etal.(2004,2006).