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外文翻译--免耕播种机的新型双翼型开沟器对玉米种区土壤物理特性和根系固定的影响和双圆盘开沟器相比较 英文版.pdf外文翻译--免耕播种机的新型双翼型开沟器对玉米种区土壤物理特性和根系固定的影响和双圆盘开沟器相比较 英文版.pdf -- 5 元

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andclimateconditions,thuspotentiallyaffectingcropemergenceandearlygrowth.ofarablecrops,progressivelyachievedinrecentyears,hasbeenconsiderable,butnewimprovementsnowavailableneedtobeindividuallytested.InafieldtrialatUdineNEItaly,theeffectsfourreductionbulkwasAsoil/seedKwww.elsevier.com/locate/stillSoilTillageResearch892006196–209penetration01671987/doi10.1016/j.stworkonsoilphysicalpropertiesintheseedzoneandoncropemergenceandearlyrootgrowthofmaizewereevaluatedindifferentsoilsovera2yearperiod2002–2003,incomparisonwiththewidelyuseddoublediskopener.Withrespecttothedoublediskopener,ingeneralthewidesweeptypeledtohighersoil–residuemixingwithoutexcessiveofthesoilcoveringindexbeingobserved,C027andC06,respectively.Thewidesweepopeneralsoshowedlowerdensityandsoilpenetrationresistanceinthetop5cmsoillayeroftheseedfurrow,althoughnogreaterrootlengthdensityfoundinmaizeatthethreeleafstage,probablyduetothesmoothingeffectcausedbythesidecoultersattheseedingdepth.certaindelayinplantemergenceinsomecaseswasalsorevealedforthewidesweepopener,whichmayberelatedtothelowercontact.Deviationsfromthisgeneralbehaviourinthevarioussoilstextureandinitialconditionsarediscussed.2005ElsevierB.V.Allrightsreserved.eywordsMaizeNotillageOpenertypeRootgrowthSeedzonephysicalpropertiesAbbreviationsCI,coveringindexDAS,daysaftersowingDDO,doublediskopenerFRSD,furrowroughnessstandarddeviationPR,resistanceRI,residueincorporationRLD,volumetricrootlengthdensitySOC,soilorganiccarbonWSO,widesweepopenerCorrespondingauthor.Tel.390498272723fax390498272774.Emailaddressmatteo.bertocco.1unipd.itM.Bertocco.–seefrontmatter2005ElsevierB.V.Allrightsreserved.ill.2005.07.011ofanewkindofwidesweepopeneri.e.,sidecoulterscurvedofupwardsintheirfinalpartandslightlyangledtowardsthedirectionThetechnologicalevolutionofseedersfordirectdrillingzonepropertiesandrootestablishmentinmaizeZeamays,L.AcomparisonwithdoublediskopenerT.Vameralia,M.Bertoccob,,L.SartoribaDipartimentodiAgronomiaAmbientaleeProduzioniVegetali,UniversityofPadova,Agripolis,VialedellUniversita16,35020Legnaro,Padova,ItalybDipartimentoTerritorioeSistemiAgroforestali,UniversityofPadova,Agripolis,VialedellUniversita16,35020Legnaro,Padova,ItalyReceived17February2005receivedinrevisedform13July2005accepted29July2005AbstractAccordingtothekindofopenerapplied,notillageseederscanvariouslymodifysoilphysicalpropertiesinrelationtosoilEffectsofanewwidesweepopenerfornotillplanteronseedResear1.IntroductionInthelastfewyears,theeconomicandenvironmentalimplicationsofconventionaltillage,suchaserosion,compactionandinvertingsoillayers,haveledtoreexaminationofnotillageeveninItalySartoriandPeruzzi,1994.Especially,intheheavysoilsofthiscountry,deepploughingaimsatincreasingsoilporosity,atleasttemporarily,inordertocreatesuitableconditionsforbothseedgerminationandrootgrowth.Simplificationofweedmanagementandhighergrainyieldsofsummercropslikemaizearegenerallyachievedwithrespecttonotillage,asevidencedbythefewdataavailableintheliteratureforItalye.g.,Bonaetal.,1995.Theperformanceofnotillageseedersdependsonseveralfactorsrelatedtofieldconditions,includingtypeandamountofresiduesatsoilsurface,openerdesignMorrison,2002andthecroptobesown.Theimplementsoftheseseedersmusthavehighflexibility,sothatvariouscropscanbesownindifferingfieldconditionswithcorrectseeddepositione.g.,density,distance,depth.Innotillagepractices,thecharacteristicsoftheseedfurrowplayanimportantroleingermination.Manyauthorshavepointedoutthatthemostsignificantfactorsregulatinggermination,suchassoilmatricpotential,temperatureLindstrometal.,1976SchneiderandGupta,1985andsowingdepthAlessiandPower,1971Mahdietal.,1998areaffectedbythesoil/openerinteractionTessieretal.,1991a,b.Inparticular,inordertomaintainconstantsowingdepth,varioustypesoflinkagesbetweenopenerandseedertoolbarhavebeenproposedduringthelastfewdecades.Forinstance,connectionwithaspringsystem,theoldestbutsimplestsolution,isnotalwaysadequatetoguaranteeuniformityofsowingdepth,especiallyinheavysoils.Greatimprovementshavebeenobtainedwithparallellinkage,sincethisallowstheopenertofollowsoilsurfaceprofilesaccurately.ManyofthecharacteristicsoftheseedzoneinnotillagedependsonthetypeofopenerattachedtotheseederWilkinsetal.,1983andthetwomaintypesused–tineanddisk–mayleadtogreatdifferences.ThetineopenertypicallycreatesanappreciableburstingeffectinthesoilandgenerallymovesaconsiderablequantityoffinedamperaggregatesT.Vameralietal./SoilTillagetowardsthesoilsurface–afactparticularlyappreciableintoolshavinganasymmetricshapeDarmoraandPandey,1995butwhichmaybenegativeifarainlessperiodoccursaftersowing,assoildryingisacceleratedChaudhuri,2001.Insimilarconditions,thediskopenermaycausemoreprogressivewaterlossinthesoillayerabovetheseedsthanthetineopenerTessieretal.,1991a,b,althoughgreatdrawbacksareobservableinwetclaysoilsbecauseapermanentunclosedfurrowiscommonlycreatedSartoriandSandri,1995.ItiswidelyrecognisedthatmanagementofcropresiduespreviouscropisoneofthemostimportantconstraintsforadoptingnotillageCarter,1994.Tineopenersshiftorganicdebrisinthesoilsurfacefromthecroprowsideways,withpossiblepluggingoftheseederinthecaseofheavyresidues,whereasdiskopenersmayleadtohairpinning,withaconsequentbadsoil/seedcontactandpossibletoxiceffectonseedlingsHultgreen,2000.Unmanagedresiduescancreatemanyproblemsindirectsowing,buttheirpresenceatthesoilsurfaceisgenerallybeneficialinlimitingsomenegativeeffectsonsoil,likeerosionandwaterlossesGillandAulakh,1990.Asregardssoilandclimateconditions,openersshouldachieveseveralaims,likeuniformityofsowing–i.e.,spacinganddepth–productionofasuitableamountoffinesoilaggregatetoensuresoil/seedcontact,reductionofwaterlosses,avoidanceofseedcontactwitheitherfertilizersorcropresiduesandlimitationoffurrowcompaction,whichmayobstructrootgrowthWillatt,1986TsegayeandMullins,1994Buenoetal.,2002.ThetypeofopenerwasfoundtoaffectemergenceandplantestablishmentmarkedlyMcLeodetal.,1992,especiallyincrustformingsoils,forwhichbetterresultsaregenerallyobtainedwiththedoublediskopenerHemmatandKhashoei,2003.Thetechnologicalevolutionofnotillageseedersforarablecrops,progressivelyachievedinthissector,hasbeengreat,butthelargenumberofimprovementsnowavailablemustbeindividuallytestedandcarefullyevaluated.Inaddition,muchoftheliteratureonthissubjectrefersalmostexclusivelytoopener/soilinteractions,withoutanalysingeffectsoncropgrowth.Theeffectsoffurrowshapeanditspropertiesonthedraftforcerequiredbydifferentopenertypeshavebeenwidelystudiedinrelationtosoilconditionsch892006196–209197andoperatingparameters,suchasdepthorspeedcomparedwiththatofadoublediskopenerDDOthesoilprofilecanbefollowedbytheopenersasregularlyaspossible.Forthisreason,ithasthreeindependentjointedsections,each1.5mwideandlinkedtotherigidframewithfourelasticjoints.Eachsectionhasfiveopeners,foratotalof15sowingrows,whicharelaidonthreeseedinglinesandequippedwithasingleparallellinkageforimprovedstability.Inaddition,eachsectionissupportedbyafrontwheelandarearpackertandemFig.2.Thelatterisanessentialcomponentfortheworkingtheseedingunitinthisseederitismadeof10wheelspersection,with3.50–8tyresand0.9barpressure.TheseederequippedwiththeDDOisaneightunitmountednotillplanterwithpneumaticseedmeteringand0.75mrowspacing,resultingina6mworkingwidth.TheDDOusedhereiscomposedofasingle,fluted,roundbladedcoulterandadoubledisk,associatedwithtwosiderollersandtworearVmountedwheelsFig.2.Performancevaluationofopenertypesrequiresdifferencesamongseederstobekepttoaminimum,Researtillairseederafrontchiselbsidecoultercendofcoultercurvedupwardsdmultipleseeddispenserepartofparallellinkage.adoptedbythenotillplanterMaxEmerge2JohnDeereItalia,Milan,Italy.TheWSOhasastraightaxis,endingwithafrontchiselandtworearside18cmwidecoulters,whichareslightlyangledtowardsthedirectionofworkandcurvedupwards908intheirfinalpart25mmhighFig.1.Thefrontchiselcutssoil25–30mmdeeperthanthecoulters.Seeddeliverytoeachunitisthroughasinglepneumatictubefromthecentralisedvolumetricmeteringsystem,whichallowstheseedertoassumeacertaindegreeofpolyvalence.Althoughvarioustypesofdepositioni.e.,rowspacingcanbeset,inourfieldtrial–asthefirsttestofthisprototypeopener–maizewassowninrows0.45mapart,adistancecommonlyusedintheexperimentalsite.ThestructureoftheseederequippedwiththeWSOincludesonerigidandonefoldingframe.ThefirstissupportedbyafrontheadshafttocoupletheseedertothetractorandtworearlowpressurewheelsforGebresenbetandJo¨nsson,1992CollinsandFowler,1996Sa´nchezGiro´netal.,2005.Instead,onlyafewstudieshaveexaminedsomecropparametersandtheygenerallydealwithdrillsforautumnsowingofcereals.Forinstance,ChaudhryandBaker1988foundthatvarioustypesofopenerledtodifferenttypesofgrowthofbarleyseedlings,i.e.,greatershootandrootweightswhenbothwingedTshapedgrooveorhoeUshapedgroovetypesareusedinsteadofthetriplediskone.Inthisframework,thepresentstudyevaluatestheperformanceofaninnovativewidesweepopener,linkedtotheframebyadoublelinkageunit.Itseffectsonsomesoilphysicalpropertiesintheseedzone,cropemergenceandearlyrootgrowthofmaizewereevaluatedinvarioussoilsovera2yearperiodinNEItalyandcomparedwiththoseofadoublediskopener,whichisthemostwidespreadinItaly.2.Materialsandmethods2.1.DescriptionofequipmentTheperformancesofanewwidesweepopenerWSOwithwhichthenotillairseederCerereTecnoagricola,Udine,Italyhasbeenequipped,wasT.Vameralietal./SoilTillage198transport.Thefoldingframeaimsatguaranteeingthatch892006196–209Fig.1.SketchofwidesweepopenerWSOattachedtoCererenoalthoughthisisnotalwayscompletelypossible,ResearT.Vameralietal./SoilTillageespeciallywhenopenerdesigndiffersgreatly,ashappenedinthiscasestudy.Nevertheless,thefollowingresultsexclusivelyfocusonthoseparametersoftheseedzonewhichweremainlyaffectedbytheworkingsystemofopenersandassociatedpresswheelsratherthanbyothermechanicalcomponents.Fig.2.Cereremultifunctiontrailednotillairseederwithawidesweepopenerbottom.ch892006196–2091992.2.FieldtrialsTestswereconductedoveraperiodof2years2002–2003ataprivatefarminTeorUdine,NEItaly458550N,138100E,8ma.s.l.infourfieldswithdifferinginitialconditionsTable1.TheeffectsofopenerswereevaluatedonsomesoilphysicaltopandMaxEmerge2notillplanterwithdoublediskopener
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