Chemicaltransformation,nutrientreleaseandchangesintheenergycontentofdecomposingrape,sunflowerandsoybeanresiduesconfinedinburiedfiberglassbagewereassessedinalaboratorystudyduringa340-dayincubationperiod.TheorganicCdecreasedbyabout70%whiletotalN,afterinitialdecay,remainedalmostconstantforeachtypeofresidue.TheNH4^+-Nwasprogressivelyoxidizedand,consequently,theNO3^-Nincreased.TheC/NrationarrowedwithlossofC.Hemicellulose,celluloseandlignindecreasedwithdifferenttrendsforeachcropresidue.Theenergycontent,wasreducedtoabout25%inrape,30%insunflowerand20%insoybeanresidues.TotalP,K,CaandMgcontentsdecreasedforeachtypeofresidueTheresultssuggestthatthethreeresiduescouldimporvethenutrientpoolofthesoil.
