03-COSTANTINI_05b-tomazic 30/12/13 18:56 Page269 UNEXPECTED RELATIONSHIPS BETWEEN δ13 C AND WINE GRAPE PERFORMANCE IN ORGANIC FARMING Edoardo A.C. COSTANTINI 1* , Alessandro AGNELLI 1, Pierluigi BUCELLI 1, Aldo CIAMBOTTI 2, Valentina DELL’ORO 2, Laura NATARELLI 1, Sergio PELLEGRINI 1, Rita PERRIA 3, Simone PRIORI 1, Paolo STORCHI 3, Christos TSOLAKIS 2 and Nadia VIGNOZZI 1 1: Consiglio per la ricerca e la sperimentazione in agricoltura, CRA-ABP, Research Centre for Agrobiology and Pedology, Florence, Italy 2: CRA-ENO Research Centre for Oenology, Asti, Italy 3: CRA-VIC Research Unit for Viticulture, Arezzo, Italy Abstract Résumé Aim :Toevaluatetherelationshipbetweencarbonisotope Méthodes et résultats :L’essaiaétéréalisépendantquatre ratio( δ13 C)andwinegrapeviticulturalandoenological ansdanslarégionduChiantiClassico(Italiecentrale),sur performanceinorganicfarming. vignesnonirriguéesconduitesenagriculturebiologique.La Methods and results :Thestudywascarriedoutforfour variétéderéférenceestleSangiovese.Onzesitesontété yearsintheChiantiClassicowineproductiondistrict choisispourlesuividelavigneetlamaturationduraisin. (CentralItaly),onfivenonirrigatedvineyardsconductedin Lesvariablesmesuréespourévaluerlaperformanceontété organicfarming.ThereferencevarietywasSangiovese. l’alcooletlateneurensucredanslemoût,letaux Elevensiteswerechosenforvinemonitoringandgrape d’accumulationdesucre,lepoidsmoyendesbaies,etles 13 sampling.Theperformanceparameterswerealcoholand polyphénolsextractibles.Le δ C,lepotentielhydriquede mustsugarcontent,sugaraccumulationrate,meanberry tige,etladisponibilitéeneaudusolontétésuivis.L’azote weight,andextractablepolyphenols. δ13 C,stemwater dusolainsiquel’azoteassimilabledanslemoûtontété 13 potential,andsoilwateravailabilitywerealsomonitored. mesurés.Le δ Cétaitcorréléaveclepotentielhydriquede Finally,soilnitrogenaswellasyeastavailablenitrogenin tigeetledéficiteneaudusol,etaindiquéunegammede themustweremeasured. δ13 Cwasdirectlyrelatedtostem stresshydriqueentreabsentetmodéréàfort.Cependant,la waterpotentialandsoilwaterdeficit,andindicatedarange relationaveclesrésultatsviticolesetœnologiquesétait ofwaterstressconditionsfromnoneandmoderatetostrong. contraireàcelleattendue.L’indicedeperformancea However,itsrelationshipwithviticulturalandoenological augmentélinéairementlorsquelestresshydriqueadiminué. resultswascontrarytoexpectation,thatis,performance D’autrepart,lamoinsbonneperformanceaétéobtenuedans linearlyincreasedalongwithsoilmoisture.Ontheother lessituationsoùl’eauetl’azoteontétélimitants. hand,theworstperformancewasobtainedwherebothwater Conclusions :Larelationinattendueentre δ13 Cetla andnitrogenweremorelimiting. performanceduSangioveseaétéprovoquéeparlafaible Conclusions :Theunexpectedrelationshipbetween δ13 C disponibilitéenazote.Lessolsétudiésonttousétéd’une andSangioveseperformancewascausedbylownitrogen faiblefertilitéetd’uneteneurenazotefaibleàtrèsfaible. availability.Thestudiedsitesallhadlow-fertilitysoilswith Parconséquent,danslesparcellesoùl’humiditédusolétait poororverypoornitrogencontent.Therefore,intheplots relativementplusélevée,l’absorptiondel’azoteparlaplante wheresoilhumiditywasrelativelyhigher,nitrogenplant aétéfavorisée,cequiaaméliorélaperformancedu uptakewasfavoured,andSangioveseperformance Sangiovese.Dansdesconditionsoùl’azoteaétéleprincipal improved.Macronutrientbeingthemainlimitingfactor,the facteurlimitant,laperformancen’ajamaiséténégativement performancewasnotlowerintheplotswheresoilwater affectéeparladisponibilitéeneaudusol.Parconséquent,le availabilitywasrelativelylarger.Therefore,thebest meilleurrésultataétéobtenudansdesconditionssans 13 viticulturalresultwasobtainedwithnowaterstress contraintehydrique,indiquéespardesvaleursde δ C conditions,atlowratherthanatintermediate δ13 Cvalues. fortementnégatives. Significance and impact of the study :Waternutritionis Signification et impact de l’étude :L’alimentationeneau 13 crucialforwinegrapeperformance. δ13 Cisamethodusedto estcrucialepourlaperformancedelavigne. δ Cestune assessvinewaterstatusduringthegrowingseasonandto méthodeutiliséepourévaluerledegrédecontrainte estimatevineperformance.Agoodperformanceisexpected hydriquesubiaucoursdelasaisonviticoleetd’évaluerla atmoderatestressandintermediate δ13 Cvalues.Abetter performancedelavigne.Unebonneperformanceest knowledgeoftheinteractionbetweenwaterandnutrient attenduepourunecontraintehydriquemodéréeetdes 13 scarcityisneeded,asitcanaffecttheuseof δ13 Ctopredict valeursintermédiairesde δ C.Peudeconnaissances vineperformance. existentausujetdel’interactionentrel’eauetlacarenceen nutriments.Cesrelationspeuventaffecterl’utilisationdu Key words :carbonisotopes,wateravailability,nitrogen, δ13 Cpourprédirelecomportementdelavigne. redgrape,performanceindex,Tuscany Mots clés :isotopesducarbone,disponibilitéeneau,azote, raisinrouge,performance,Toscane manuscript received 12th February 2013 - revised manuscript received 11th August 2013 J. Int. Sci. Vigne Vin , 2013, 47 , n°4, 269-285 *Correspondingauthor : [email protected] - 269 - ©Vigne et Vin Publications Internationales (Bordeaux, France) 03-COSTANTINI_05b-tomazic 30/12/13 18:56 Page270 Edoardo A.C. COSTANTINI et al. INTRODUCTION Chardonnay(OjedaandSalmon,2011).Suchresults, inadditiontoothermoreecologicalmotivations, Thebestterroirsforredwineproductionarethosein enhancedthelimitationofnitrogenfertilizationin whichsomesoilfactorsarelimitingtovinevigourand premiumviticultureandtheadoptionofbiological berrysize(vanLeeuwenandSeguin,2006),sothat farming.Currently,organicviticulturecoversabout grapesripencompletelybutslowly.Theselimiting 80,000 hainEuropeand44,000inItaly,butnotmuch factorsmaybechemical(limitednitrogennutritionor isknownonitseffectivefeedbackonwinegrape ionantagonisms)orphysical(insufficientwater performance. supplyduringcertainphasesofthegrowthcycleof thevine). Althoughknowledgeofwaterandnitrogennutritionin avineyardisessential,itsassessmentisdifficult,since Asawhole,nitrogennutritionandwatersupply soilwaterandnitrogencontenthaveastrongtemporal duringcertainphasesofthegrowthcycleofthevine and3Dspatialvariability,especiallyinrainfed areconsideredessentialfactorsofwinequality.Their cultivationandbiologicalfarming,wheretheuseof roleindeterminingtheterroireffecthasbeen syntheticnitrogenfertilizersisnotallowedThen,a experiencedinmanywineproducingareasandwith commonpracticeisthemonitoringofviticulturaland severalvarietiesincluding,amongothers,France,with oenologicalindicators,likeyieldcomponents,leafand Cabernet-Sauvignon(Choné et al. ,2001),Merlot stemwaterpotential( Ψstem),leafanalysis, (Tregoat et al. ,2002)andSauvignonBlanc(Peyrot oenologicalparameters,andsensoryassessment. desGachons et al. ,2005),AustraliawithSauvignon Blanc(White et al. ,2007),HungarywithKékfrankos Recently,inadditiontotraditionaltechniques,anew (Zsófi et al. ,2009),andUSAwithCabernet- physiologicmarkerhasbeenintroducedforan SauvignonandChardonnay(Chapman et al. ,2005 ; integrativeevaluationoftheoverallvinewateruptake Deluc et al. ,2009). conditionsduringtheripeningperiod,i.e.,theratio betweenthetwostablecarbonisotopes 13 C/ 12 C,called Grapevinenitrogennutrition,inparticular,influences δ13 C.Actually,stomataclosureunderwaterdeficit 12 qualitycomponentsinthegrapeand,ultimately,the restrictswaterandCO 2 flow ;as Cispreferentially wine.Inaddition,fermentationkineticsandformation fixedduringthephotosynthesisprocess,whenstomata offlavour-activemetabolitesarealsoaffectedbythe areopen,thisresultsinarelativeincreaseinthe nitrogenstatusofthemust(BellandHenschke,2005). concentrationoftheheaviestisotope 13 C.Theisotopic Plantuptakeofsoilnitrogenincreasesthe ratiocanbemeasuredeitherinthemustsugarsupon concentrationofmajornitrogenouscompoundssuch harvestingorinthealcoholofthewineproduced(van astotalnitrogen,totalaminoacids,arginine,proline, Leeuwen et al. ,2001 ;Tregoat et al. ,2002 ;van ammoniumand,consequently,yeast-assimilable Leeuwen et al. ,2003),thoughthereisashiftof δ13 C nitrogen(YAN)infruit.IntermediatemustYANoffers betweenethanolandsugars,duetothelossof 13 theoptimumbalancebetweendesirableand C-enrichedcarbonatomsofglucoseasCO 2 during undesirablechemicalandsensorywineattributes(Bell fermentation.Rossmann et al. (1996)foundfor1,631 andHenschke,2005).Whenthenitrogen Italiansamplesameanshiftof1.7‰. concentrationinmustislow,thereisadirect 13 relationshipbetweeninitialnitrogenconcentrationand Reported δ C valuesinthemustsugarsrangefrom- thetotalconcentrationofhigheralcoholsinthewine 21.0to-28.0‰,with-25.5or-26.0‰considered (Äyräpää,1971). thresholdvaluesbetweenwaterdeficitandnon- limitingwaternutrition(vanLeeuwen et al. ,2003 ; Watersupplyduringspecificphasesofthegrowth Deschepper et al. ,2006).Accordingtothesame cycleofthevineisalsoconsideredanessentialfactor authors(vanLeeuwen et al. ,2003 ;Tregoat et al. , ofwinequality.Amildwaterdeficitstress,in 2002),valuesofabout-23‰inthemustcorrespondto particular,isconsideredtoenhancegrapequalityfor aminimum Ψstemcloseto-12 bar,avaluethat theproductionofredwines(vanLeeuwen et al. , matchedanoptimalcorrelationwiththeberrysugar 2009).Morespecifically,Tregoat et al. (2002)found accumulationrate.Beingcorrelatedwithimportant thatMerlotdevelopmentandberrycompositionwere componentsofmustquality(e.g.,sugarcontentand moreinfluencedbywateruptakeconditionsthanby titratableacidity), δ13 C canalsobeusedtomapterroirs vinenitrogenstatusinBordeaux.Besides,atsimilar atdifferentscales(vanLeeuwen et al. ,2001 ; wateruptakeconditions,lowvinenitrogenstatus Guix-Hébrard et al. ,2007 ;ZuffereyandMurisier, increasedberrypotential.Ontheotherhand,a