A
sweet
deal?
Sugarcane,
water
and
agricultural
transformation
in
Sub-Saharan
Africa
T.M.
Hess
a,
J.
Sumberg
b,
T.
Biggs
c,
M.
Georgescu
d,
D.
Haro-Monteagudo
a,
G.
Jewitt
e,
M.
Ozdogan
f,
M.
Marshall
g,
P.
Thenkabail
h,
A.
Daccache
i,
F.
Marin
j,
J.W.
Knox
a,*
aCranfieldWaterScienceInstitute,CranfieldUniversity,Cranfield,BedfordshireMK430AL,UK b
InstituteofDevelopmentStudies,UniversityofSussex,Brighton,EastSussexBN19RE,UK
c
SanDiegoStateUniversity,5500CampanileDrive,SanDiego,CA92182,USA
d
ArizonaStateUniversity,CoorHall,975S.MyrtleAve.,Tempe,AZ85287,USA
e
UniversityofKwaZulu-Natal,Durban4041,SouthAfrica
f
UniversityofWisconsin—Madison,1710UniversityAvenue,Madison,WI53726,USA
gWorldAgroforestryCentre(ICRAF),UnitedNationsAvenue,P.O.Box30677,Nairobi00100,Kenya hU.S.GeologicalSurvey,2255N.GeminiDrive,Flagstaff,AZ86001,USA
i
MediterraneanAgronomicInstituteofBari(IAMB),ViaCeglie,9-70010Valenzano(BA),Italy
j
BiosystemsEngineeringDept.,ESALQ,UniversityofSaoPaulo,Brazil
ARTICLE INFO
Articlehistory:
Received21December2015
Receivedinrevisedform31March2016 Accepted14May2016
Availableonline6June2016
Keywords: Agriculture Development Livelihoods Impact Sugar Waterresources ABSTRACT
Globally,theareaofsugarcaneisrisingrapidlyinresponsetogrowingdemandsforbioethanoland
increasedsugardemandforhumanconsumption.Despiteconsiderablediversityinproductionsystems
and contexts,sugarcaneis aparticularly“highimpact”cropwithsignificant positiveandnegative
environmentalandsocio-economicimpacts.OuranalysisisfocusedonSub-SaharanAfrica(SSA),which
isacriticalregionforcontinuedexpansion,duetoitshighproductionpotential,lowcostofproduction
andproximity,andaccess,toEuropeanmarkets.Drawingonasystematicreviewofscientificevidence,
combinedwithinformationfromkeyinformants,stakeholdersandaresearch-industryworkshop,we
criticallyassesstheimpactsofsugarcanedevelopmentonwater,soilandairquality,employment,food
securityandhumanhealth.Ouranalysisshowsthatsugarcaneproductionis,ingeneral,neitherexplicitly
goodnorbad,sustainablenorunsustainable.Theimpactsofexpansionofsugarcaneproductiononthe
environmentandsociety dependontheglobalpoliticaleconomyofsugar,localcontext,qualityof
scheme,natureoftheproductionsystemandfarmmanagement.Despitethreatsfromclimatechange
andforthcomingchangesinthetraderelationshipwiththeEuropeanUnion,agriculturaldevelopment
policies aredriving national and international interest and investment in sugarcanein SSA, with
expansionlikelytoplayanimportantroleinsustainabledevelopmentintheregion.Ourfindingswill
help guide researchers and policy makers with new insights in understanding the situated
environmental and social impacts associated with alternativesugar economy models, production
technologiesandqualitiesofmanagement.
ã2016TheAuthors.PublishedbyElsevierLtd.ThisisanopenaccessarticleundertheCCBYlicense
(http://creativecommons.org/licenses/by/4.0/).
1.Introduction
Sugarcane is an important crop globally. Whilst the health effectsofsugarconsumptionarevigorouslydebated(Ruxtonetal., 2010), and there is uncertainty about its future as a biofuel feedstock,supportingandexpandingsugarcaneproductionisan economicallyimportant elementof thedevelopmentagendain
many Sub-Saharan Africa (SSA) countries.1 Significant future
expansion of sugarcane is likely to have major impacts and repercussions on agricultural land use and water resources, livelihoods, foodsecurityand ecosystemservices,whilst poten-tially providing major infrastructure and economic benefits. Furtherdevelopmentof thesugar sectorwilltakeplaceagainst
* Correspondingauthor.
E-mailaddress:j.knox@cranfield.ac.uk(J.W. Knox).
1
TheSSAdesignationiscommonlyusedtoindicateallofAfricaexceptAlgeria, Egypt,Libya,Morocco,TunisiaandWesternSaharam—theSudanandtheislandsof Madagascar and Mauritius are included in SSA. http://unstats.un.org/unsd/ methods/m49/m49regin.htm.
http://dx.doi.org/10.1016/j.gloenvcha.2016.05.003
0959-3780/ã2016TheAuthors.PublishedbyElsevierLtd.ThisisanopenaccessarticleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).
ContentslistsavailableatScienceDirect
Global
Environmental
Change
abackdropofachangingclimatewithgreaterrainfalluncertainty andincreaseddroughtrisk puttingpressureonyieldsinrainfed production(Knoxetal.,2010), risingdemandfor irrigationand reducing available water supplies (Kusangaya et al., 2014). An increasedrelianceonfertilisertoimprovecropyieldscoupledwith theintroductionof newvarietiesresistanttoclimatevariations based on genetically modified cane could also lead to major unintendedconsequencesforlocalecosystems.
Cane production and processing are important sources of employmentandforeignexchangetoSSAbutareassociatedwith potentiallyintensedemands onwaterand otherenvironmental resources.Caneplaysacentralroleinanumberofcurrentpolicy and academic debates. Some, for example, look to the cane industry for tried and tested models for linking small-scale producers to value chains through outgrower schemes. The argument is that models such as these can help power the transformationofAfricanagriculture.Otherslinkcaneproduction tothestrongfocusoninfrastructuredevelopmentthatisevidentin much of the continent. There is, for example, close alignment betweentheplansforwater,transportationandpower infrastruc-tureinthedevelopmentcorridorsofeasternandsouthernAfrica, andtherequirementsofamodern,large-scalesugarindustry.
However,therearealsothosewhouseexamplesintheAfrican sugarindustrytoillustratetrendsinglobalagriculturethatinsome casescanoverridenationalpolicyandaffectlocalbusiness and livelihoods. Sugar development has, in particular cases, been linkedtolandandwater‘grabbing’(e.g.Mataveletal.,2011)aswell asnegativedownstreameffectsincludingreducedannualandlow flowsandincreasedsedimentation(JewittandKunz,2011).More generally,sugarcanecanbeplacedatthecentreofdebatesonthe water-food-energynexusand thepressures onthe agricultural sector to increase crop productivity and improve water use efficiency.Therecentglobalinterestaroundtheuseofsugarcaneas abiofuelstock(EurObserv’ER,2012)putstheeconomic, develop-mentalandenvironmentaltrade-offsthatareattheheartofthis nexusintostarkrelief.
Sugarcanehascharacteristicsthatareassociatedwith particu-larenvironmentalandsocialoutcomes.Theseincludethecrop’s waterrequirements,andinSSA,thehighrelianceonirrigationfor production.Additionally, sugarcane qualitydeterioratesrapidly aftercutting,sothecaneneedstobemovedpromptlyfromthe fieldtothemill.Asfreshlycutcanehashighwatercontent,itis expensivetotransport.Thereforetolimitcosts,caneisgenerally grownclosetothefactorysiteandcandominatethelanduseinthe localityofthemill.Thisconcentrationofactivityresultsinaneed forsignificant infrastructuralsupport,including housing,roads, schools, medical facilities and recreational facilities for people employedinthegrowing,cuttingandprocessingofcane.Thereare alsopotentialeconomicreturnstoscale;and,dependingonthe technologyused,potentiallyhighlabourdemandsforbothcane productionandprocessing.Individually,noneofthese character-istics are unique to sugar production in SSA, but when they coalesceinparticularproductionsystemsandlocations,significant economic, social and environmental impacts (positive and negative)arepossible.
Theargumentthatwemakeinthis paperisthatdespitethe considerablediversityofsugarcaneproductionsystemsobserved in SSA, sugarcaneshould beconsidered as a particularly “high impact”cropinrelationtobothwaterandlabour.Weusetheterm highimpacttorefertoacropassociatedwithsignificantpositive and/ornegative environmental and/or socio-economic impacts. Thisargumentunderpinsourinterestinthesituated environmen-taland social impactsassociated withdifferentsugar economy models (mega-estates, independent growers, small-scale out-growers,mixedmodels),productiontechnologiesandqualitiesof management.Ultimatelyweareinterestedinthecircumstances,or
combinationsoffactors,thatwouldfavourmodelsofsugarcane developmentinSSAthatarebothmoreenvironmentally sustain-ableandsociallyacceptable,andhowcurrentindustrytrendsand existingagriculturaldevelopmentpoliciesmapontothese.Inthis context,andaspartofabroaderinternationalefforttounderstand theenvironmentalandhydro-socialimpactsofglobalsugarcane expansion, theobjective of this paperwas toprovidea critical assessmentofscientificevidence,expertandindustryopinionon thewater, land,economic and social impacts of the sugarcane industryinSSA.Assuchourfocusisontrendsincultivatedarea andproduction,theimpactsonlandandwaterresourcesandthe industry’slinkswith regionaleconomic developmentand rural livelihoods.Bycombininggeospatialdataonsugarcanecroplands with water resources availability, we assess the rainfed and irrigatedareas‘atrisk’todevelopnewinsightsonthegeographical variation in water resources and their political and social consequences.Intheconcludingsectionofthepaperweidentify thefutureopportunitiesandemergingresearchquestionsforthe scientific community.The paper is based ona combination of evidence from a review of the literature, a research-industry workshop,discussionwithkeyinformantsincludingstakeholders and industry, and expert opinion. First we review the current status of sugarcane production in SSA and then discuss the evidence from the literature for the environmental and social impactsofsugarcaneexpansion.Weconcludebyconsideringthe wayforwardandthepotentialcontributionofexpanded produc-tionofsugarcanetosustainabledevelopmentinSSA.
2.SugarcaneproductioninSSA
Globally,sugarcaneisthe14thmostextensivecropintermsof cultivated area, equivalent to 1.75% or 26.5Mha of the total globalcroplandarea(Leffetal.,2004).In2013globalproductionof sugarcane was estimated to be 1.9 Gt, with Brazil and India accounting for 39% and 18% of global production, respectively (FAOSTAT,2015).AlthoughSSArepresentsonly4%ofcurrentglobal production, it is considered a critical region for continued expansion due to its high production potential, low cost and proximity toEuropeanmarkets (Tyler, 2008). Fig.1 shows the reportedspatialdistributionofsugarcaneproductionacrossAfrica, derivedfrommodellingstudies,highlightingregionsof concen-trationinwest,eastandsouthernAfrica.
SugarcaneisgrowninmostcountriesinSSA,butfiveaccount formorethanhalfthetotalproduction(FAO,2015):SouthAfrica (23%),Sudan(includingSouthSudan)(9%),Kenya(7%),Swaziland (7%)andMauritius(7%).SugarcaneproductioninSSAmorethan tripledbetween1961and2013(Fig.2)(Jolly,2012;Kalindaand Chisanga,2014).Theoveralltrendsinsugarproductionare,inpart, climaterelated,forinstancetheimpactofdroughtconditionsin 1993/4contributedtoasignificantreductioninproduction.
CostsofproductioninSSAarerelativelylow,dueprimarilyto theidealgrowingconditions (undulatingtopography,claysoils, availability of supplementary irrigation, and ambient weather conditions—notablytemperatureandsolarradiation)supporting highgrowthratesandconversiontosucrose.Sugarcaneproduction isreportedtoachievethehighestyieldbetweenlatitudesof30N and30S(Watsonetal.,2008)whichessentiallyencompassesallof SSA. For example, the sucrose production of southern African sugarcanetypically averages>1t/ha/month,whereas the global averageis0.5t/ha/month(Tyler,2008).TheSSAregiontherefore has high production potential with sugarcane understandably attractingsignificantinternationalinterestasacommoditycrop withhighinvestmentpotential.
CaneproductioninSSAtakesplaceinavarietyofcontexts,on differentscales,andusingcontrastingtechnologiesand organisa-tionalforms.Sugarcanemayberainfedorirrigated;producedon
largecommercialestates,orgrownbyout-growerswhoseplots rangeinsizefromverylargetoverysmall;inlargeflatfieldsorin small fields on steep slopes, and cut by hand or harvested mechanically.Canemaybetransformedintoraworrefinedsugar, or ethanol, in factories that may be owned by international, regionalorlocalfirms,orbyout-growerassociationsusingmoreor lessefficientfactorytechnologies;andsoldontodomestic,regional orinternationalmarkets.
Oneincreasinglyimportantnarrativepaintsthesugarindustry as a critical part of agricultural and economic development strategy in Africa, through its contributions to infrastructure
development,jobcreationandthebalanceofpayments(Lankford and Dickinson,2007;Watkins, 2004;Watsonetal.,2008).This narrative is compelling because many of the region’s sugar-producingcountriesareamongthepoorestintheworld.Anumber of SouthernAfricanDevelopmentCommunity(SADC)countries, includingTanzania,Malawi, Zimbabweand Mozambique(SADC, 2013)haveidentifiedsugarcaneproductionasakeycomponentof majorinitiativestodevelopso-calledgrowthcorridors(Pauland Steinbrecher,2013).
2.1.Acomplexinstitutionalenvironment:markets,quotasandprices Duetoitsrelativegeographicalproximityandcolonialhistory, theEuropeUnion(EU)markethasbeenparticularlyimportantto Africa’ssugarsector.TheEUistheworld’ssecondlargestconsumer ofsugar(Czarnikow,2014)andwasthelargestimporterofsugar between2008and2011(ISO,2014).ManySSAcountiesbenefited fromschemesgivingpreferentialaccesstotheEUmarket,making sugarproductionespeciallyattractive.Thesewereinitiatedaspart of the 1975 Lomé Convention betweenAfrican, Caribbean and Pacific(ACP)countriesandtheEU,andwereretainedinthe follow-onCotonouAgreementsignedin2000.Duty-freeandquota-free accessforsugarisenshrinedinthenewgenerationofeconomic partnershipagreements(EPA)betweenACPcountriesandtheEU. Inaddition,leastdevelopedcountries(LDC)whichwerenotACP countries or which had not yet signed an EPA (e.g. Malawi, Mozambique,Zambia),stillenjoydutyandquota-freeaccesstothe EUmarketunderthe2001Everything-But-ArmsInitiative.
ThepriceofsugarwasparticularlyhighforACPcountriesbefore 2006astheEUboughttheirsugaratpreferentialpricesthatwere typicallydoubleortripletheworldmarketprice(TerryandRyder, 2007).AlthoughtheEUdecreaseditsreferencepriceforsugarby 36% between2006 and2010afterundertaking majorEuropean sugarreforms,thispricewasstillhigherthantheworldmarket price(Jolly,2012),continuingtoofferbeneficialconditionsforACP andLDCcountries.Inaddition,sugarpricesintheEUhavebeen particularly high in the past few years, which has benefited exporters to Europe (European Commission, 2013). After 2017, productionquotaswithintheEUaretobeliftedandasaresult,itis
Fig.1.Spatial distribution ofsugarcane productionareas in Africabased on modelleddata(After:HarvestChoice,2015a,b).
predictedthatby2023sugarimportsintotheEUwillbeatonlya halftheir2010level(Agritrade,2014).
The Africa-EUand regionalmarketdynamicscreate peculiar opportunities and niches. South Africa supplies its neighbour Mozambiquewithsugarfordomesticconsumptionandtosupply thedrinksindustry,becausethemajorityofMozambique’sown productionisexportedtotheEUinordertocapturehigherprices (Sulleetal.,2014).Similarly,corporations fromcountrieswhich havenotbenefitedfromunrestrictedtradeaccesstotheEU,suchas South Africa, and international corporations from the UK and France,havemovedtoexpandoperationsinsomeofthepoorer countriesintheregiontotakeadvantageofthesetradeagreements (Yambaetal.,2008).Forexample,IllovoSugarLtd.operatesinsix southernAfricancountriesandisreportedtogenerate80%ofits profitfromnon-SouthAfricanoperations;ABSugar(whoowna 51%stakeinIllovo)wasabletosupplyitssugarrefineriesinEurope withmostlyduty-andquota-freesugarfromitssouthernAfrican operations(Richardson,2010).
2.2.Theinfluenceofbiofuels
A major driver of demand for biofuels is renewable fuel-blending mandates, with the aim of reducing greenhouse gas emissions,andtheEU’sinabilitytomeetthem(Richardson,2010). However, it is not altogether clear whether the demand for biofuels,especiallyethanol(LockeandHenley,2013),hasyethada significantimpactonsugarcaneproductioninAfrica(Thaler,2013). Mostoftheethanolproducedintropicalcountriesusessugarcane products(canejuiceormolasses)asafeedstock(FAO,2008)and somebiofuelprojectsbasedonnewsugarcaneplantationshave emergedasaresult(Shumbaetal.,2011).However,Jolly(2012)
arguesthat intheSADCcountries,increasedglobaldemandfor ethanolhasnotequatedtoahigherproductionofsugarcane.The relatively high prices associated with the preferential trade agreementsdiscussedabove,alongwithhighlocalpricesinsome countriesmeanthatsugaristargetedtothesemarkets.Demandfor biofuelsisextantandincreasing,givingsugarproducersareason toturnexcess molasses fromthe millingprocess into ethanol. Some producers are gearing up to take advantage of this opportunitybyinvestinginmodernsugarmillswiththecapacity toproduceethanoldirectlyfromcanejuice(AnnualSADCSugar Digest,2013).SomeAfricancountries,notablyMozambique,have also attempted to emulate Brazil’s success in cane ethanol production, by relying heavily on Brazilian biofuel technology expertiseanddevelopmentassistance.Demandfortechnicaland financial supporthascoincided withBrazil’s desireto increase South–Southcooperationandleverageitshistoricalandcultural tieswithAfricaformutualeconomicbenefit(Thaler,2013).This hasprovidedanopportunitytotakeadvantageofAfrica’slow-cost environmenttoexpandethanolproductionandaccesspreferential localand international(e.g.China) markets. Driven bygrowing concernsregarding theenvironmental sustainability of biofuels and particularly issues relating to high water usage and high greenhousegasemissions associated withland preparation for energycropping,analternativestrategynowbeingconsideredin SouthAfricaistheuseoflignocellulosicfeedsuchassugarcane bagasseforsecondgenerationbiofuels(Petersenetal.,2015).This wouldnotonlythreatennewbiofuelsentrantsintotheSSAmarket based on sugar cane, but could also impact on the current dynamicsofsugar cane fromawater-energy-food (WEF)nexus perspective.
AsanumberofAfricancountriesareentirelyreliantonimports tomeettheirtransportationfuelneeds,manyhaveannouncedthe introductionof mandatory blending requirements (von Maltitz andSetzkorn,2013;Lane,2013;PaciniandBatidzirai,2012).This mayhelpreduce foreignexchangeoutlays (Francoet al., 2010)
while achieving a greater level of energy autonomy. For the region’s sugar producers, faced with increasingly less-advanta-geousEUprices,combinedsugarandethanolproductionmaybe anattractivewaytoaddvaluetothesugarsupplychain(Borras et al., 2011). Ethanol production does not necessarily require additionalcaneproduction,orimpactonsugaroutput,asmuch ethanolisproducedfrommolasses,whichisanoftenunderutilised by-productof sugar factories (Chamdimba, 2009; Yamba et al., 2008).Again,thisvisionofamodern,flexiblesugarindustrythat canmakeastrategiccontributiontothenationalenergyeconomy is an important partof the rationale for sugar production and processing having a key place within the large-scale growth corridors.
3.Land,water,soilandatmosphereimpacts
Commercialsugarcane productionis associatedwith poten-tiallylarge-scalelandusechange,bothdirectandindirect,andthus impactsonwater,energyandnutrientcycles.Dependingonthe scale of development and choice of production system, these impactswillbecomeevidentatlocalandregionalscales.However, assessingtheextentofthesechangesandimpactsischallenging.
3.1.Landusechange
Thedriversandopportunitiestoproducesugarcanewithhigh sucroselevelsatrelativelylowcost,preferentialaccesstotheEU market,andthepromiseofincreaseddemandforbioethanolhave fuelledrecentinterestintheexpansionofsugarcaneinSSA.With an estimated 6 million hectares of land available for sugar production in six southern African countries, and with the estimated potential in Malawi, Mozambique and Zambia alone beinggreaterthanalloftheexistingsugarcaneproductioninthe SADC region (Watson et al., 2008), there is a perception of abundant land for expansion (Watson, 2011). In some cases sugarcane development occurs through the rehabilitation of existing estates, while other cases involve the conversion of existing agricultural land previously used by small-scale pro-ducers,ordevelopmentoflarge-tractsofpreviouslyuncultivated land.Thetwolatterroutesimplydirectand/orindirectlanduse change, and both warrant careful consideration. Expansion through conversion of existing agricultural land may involve dispossession,displacementanddisruptedlivelihoods,whichcan reduce food production and threaten food security. Expansion throughdevelopmentofpreviouslyuncultivatedlandmaydisrupt longestablishedgrazingpatternsandgatheringactivities,threaten biodiversity and disrupt otherland-related ecosystem services. Thusevenconversionofpreviouslyuncultivatedlandcouldhave importantlivelihoodsandecosystemside-effects.Ultimatelythe significance oftheseeffects willdependonlocalcircumstances andthetypeandscale(i.e.anindividualestateorsugarcluster withinadevelopmentcorridor)ofsugardevelopment.
To date there have been few studies of land use change associatedwithsugarcaneexpansioninSSA.Bycomparison,the developmentofsugarcaneinBrazildisplacedmainlypastureand agriculturallands,withonly0.6%displacingforestorreforested areas (Adami et al., 2012; Zuurbier, 2008).Some authors have argued that even though sugarcaneexpansion hasnot directly replacednaturalbiomes,ithashadanindirectimpactwhenthe agricultural activities that are displaced by expansion move towardsor intonaturalor sensitivebiomes.Unlikedirect land-use change, indirect change is more challenging to evaluate (
Zuurbier,2008)however,literaturefromBrazilconfirmsanegative andstatisticallysignificantcorrelationbetweensugarcane expan-sionanddeforestation(deSáetal.,2013).
3.2.Waterresources
Waterisacrucialresourcetothesugarindustrybothforcane production,processingandrefining(Hessetal.,2014).Theimpacts ofsugarcaneexpansiononwaterresourceswilldependonlocal agrometeorological conditions, whether the crop is rainfed or irrigated, and the land cover it replaces (Bagley et al., 2014). Irrigation is required in geographical regions where rainfall is insufficient to meet plant water demands (Fig. 3). Apart from CameroonandMauritius,asignificantproportionofthecropped caneareainmanySSAcountriesreliesonirrigation.Aregressionof theannualsugarcaneproduction(t)inSSAagainstirrigatedand rainfed areas (ha) shows that the irrigated sugarcane has, on average, approximately three times the productivity (98t/ha) compared to rainfed sugarcane (32t/ha). However, there is potentialforsugarproductiontohavesignificantimpactsonlocal wateravailability byreducing both thequantity and qualityof waterforotheruses.
The withdrawal and transmission of water from rivers, groundwater or constructed reservoirs can affect flow regimes and aquifers furtherafield. As withany irrigated cropping, the impact on downstream water availability will depend on the locationofproductionwithinthecatchmentaswellasonlocalsoil andtopographyconditions,farmmanagementpracticesandlocal climateconditions(Schmidt,1997).Incontrasttootherirrigated cropswhicharefallowand/orunirrigatedduringpartoftheyear, sugarcaneisaperennialcropthatcanbeirrigatedallyear,thus increasingannualwaterconsumptioncomparedtootherirrigated cropping systems. In addition, sugar mills and refineries also requirelargequantitiesofwater,withcanewashingestimatedto require 3–10m3 per tonne (Cheesman, 2004). Because of the
concentrationofproductionaroundfactorysites,sugarcanemay havegreatpotentialtomodifylocalwaterbalancesandtherefore affect available water supplies for competing uses (household/ domestic/industrialsupply,environmentalflows)andimpactthe qualityand dynamicsatwatershedleveland beyond.India,the world’ssecondlargestproducerofsugarcane,providesanextreme example where irrigated sugarcane has contributed to severe
scarcityofbothsurfaceandgroundwateratarangeofspatialscales inseveralriverbasins(Shrivastavaetal.,2011;Rodelletal.,2009). Thereispressingneedtoavoidthetrapofgroundwater-dependent irrigated sugarcane that rapidly undermines its sustainability throughgroundwateroverdraft,especiallyinnorthernIndiawhere deepaquifersarebeingrapidlydepleted,thoughthedecentralized natureof groundwater extractionin Indiacomplicateseffective governance(Shah,2010).
Itisnotonlyirrigatedcanethatcanimpactstreamflows,but also rainfedcane. An increase inthe areaof rainfedsugarcane mightleadtoachangeinavailablewaterresources,assugarcane mayhave a differentannualwater usetothelanduses that it replaces (Warburton et al., 2012). In Brazil, modest, or even positiveimpactsofsugarcaneonsurfacewaterquantityhavebeen identifiedaswateruseunderrainfedsugarcaneiscomparableto thenativeforestduringthegrowingseason,butlowerforseveral monthsfollowingharvest(Georgescuetal.,2013).Similarly,Loarie etal. (2011)reportedlowermeanannualcropwateruseunder sugarcanecomparedtotheoriginalcerradoforest,butsugarcane conversion from agriculture (crop and pasture) resulted in increasedcropwateruse(Table1).
SSAischaracterisedbyarangeofhydro-climaticregionswith highrainfallvariability(Conwayetal.,2009).Ingeneralterms,SSA cannotbeconsideredwaterpoor(LautzeandGiordano,2007)asit stores9%oftheworld’sfreshwaterresources.Withonly11%ofthe globalpopulationinSSA,italsohasalowerpercapitarateofwater withdrawalandlowerlevelofirrigatedareathananyotherregion globally.However,somecountries,includingSudan,Swazilandand Tanzania, have significant areas of both rainfed and irrigated productionwithin areasof‘high’ or‘extremelyhigh’water risk (Gassert et al., 2014) (Table 2). This means that not only is sugarcane production exposed to risks from reduced water availability(inthecaseofirrigatedsugarcane),butalsothatcane productionmaybeexacerbatingwaterriskstootherusersinthe catchment.
InSouthAfrica,60%ofthecountry’swatersuppliesarealready fullycommitted,andtheGovernmenthashighlightedthesevere limitationsontheavailabilityofadditionalwaterforallocationto
newuses(DME,2007;Mapakoetal.,2012).Competitionforwater resourcesincertaincatchmentsinSouthAfricaisforcingthesugar industrytojustifyitsuseof irrigationonthebasis ofeconomic returntowaterused(Schmidt,1997).Although80%ofsugarcanein SouthAfricaisnotirrigated,thelowratioofrunofffromrainfall, spatialheterogeneityinrainfallpatternsandthehighintra-and inter-annualvariabilitymakewaterresourceshighlysensitiveto changesinlandcover(JewittandKunz,2011).Asaconsequence, growersmayberequiredtoapplyforawaterlicenceevenunder rainfedconditionsundertheNationalWaterAct(Governmentof SouthAfrica, 1998)which allows for theregulation land-based activities which reduce stream flow (Stream Flow Reduction Activity)(Jewittet al., 2009). Somestudies(e.g. Mozambique’s Limpopo River Basin) have recommended limits to planned sugarcane developments (Van der Zaag et al., 2010) however, other countries, including Tanzania and Zambia, appear deter-minedtocommitadequatewaterresourcestosupplyagricultural developmentprojectsinrecognitionoftheireconomic contribu-tion(Kgathietal.,2012).
Futurechangesinirrigationtechnologytosupportoutgrower sugarcane expansion could also create new water resource managementchallenges.Forexample,inSouthAsia,the availabil-ity of small electric pumps has supported rapid expansion of irrigation by smallholders, with concomitant challenges in managingtheactivities of millionsofindividual welloperators (Shah,2010).Givencurrentandprojectedeconomicgrowthrates inAfrica,therewilllikelybemajorshiftsintechnologyusedfor sugarcaneproduction(andothercrops)andwatershed manage-ment that may impact on water resources more than simply expansionofthecanecultivatedarea.
3.3.Waterquality
PublishedstudiesonwaterqualityimpactsofcaneinAfricaare verylimitedandfocusonnutrientsandsalinity,highlightingthe limitedextentofagrochemicalmonitoringatthecatchmentscale. Aswithotherlarge-scalecommercialcrops,sugarcaneproduction involvestheapplicationof fertilizers,herbicidesand pesticides.
Consequently,anincreaseinnutrientloads,salinityanddissolved and suspended solids are the most common threats to water qualityin bodies receiving outflowsfromsugarcanefarms. The impactofgrowingsugarcaneonwaterqualityrangesfromthefield tocatchmentlevelsthroughrivers and lakes,shallowand deep groundwater, and even reaching estuarine and coastal areas. Several studies report water contamination from cane farming practices,mainlyassociatedwithfertiliserandpesticide applica-tion(i.e.ratesandthetimingofapplication)orasaconsequenceof themethodof harvesting(manual harvestingwithpre-burning increases theconcentrationof dissolved and suspended solids) (Table3).
Herbicides are the most widely used agro-chemical in sugarcaneproduction(Armasetal.,2005);watercontamination risksareextensivelycoveredinthescientificliteraturebasedon studiesinAustralia,theUSAandBrazil.Surfacewatersinareasof sugarcaneproductionhavealsobeenshowntocontainherbicides andpesticidessometimesexceedingecological(e.g.Davis etal., 2013)ordrinkingwater(e.g.Mitchelletal.,2005)guidelines.The impactsofsugarcaneproductiononwaterqualityarealsolinkedto the activities of sugar mills and refineries (Pawar et al.,1998; Shivappaetal.,2007;Tchounwou,1999).Studiesontheeffectsof wastewaterfromethanolproductionhavehighlightedincreasesin organicmatter,higherconcentrationsof totalsuspended solids, andanincreaseintemperatureofreceivingwaters(Smeetsetal., 2008).
It is evident that without sufficient environmental and regulatorycontrols, futureexpansion ofsugarcanein SSAcould posea threattowaterquality.Giventhescarcenatureofwater resourcesinpartsoftheregion,pollutantloadsarelikelytobe higherinriversandlakesputtingdrinkingwatersuppliesatrisk. However, newenvironmental regulations, including the imple-mentation of ISO standards and participation in BONSUCRO (http://www.bonsucro.com)accreditation,arehelpingtomitigate these impacts particularly for newcane developments. Under-standing the impacts of high seasonal variability will also be pertinent, and some adaptation in farming techniques will be neededtominimisefuturewaterqualityrisks.
Table1
Totalirrigatedandrainfedsugarcaneharvestedareas(ha)inSSAwithindifferentwaterriskcategories(After:HarvestChoice,2015a,b;Gassertetal.,2014). Sugarcaneproduction Waterresourceriska
Low Lowtomedium Mediumtohigh High Extremelyhigh
Rainfed 76.1 246,302 419,411 27,584 52
Irrigated – 95,716 360,958 48,107 3129
a
Physicalwaterriskisdefinedastheexposuretochangesinwaterquantitythatmayimpactacompany’sdirectoperations,supplychainsand/orlogistics.
Table2
Estimatedarea(ha)ofrainfedandirrigatedsugarcaneinSSAwithinareasdefinedas‘high’and‘extremelyhigh’waterrisk(Sources:HarvestChoice,2015a;Gassertetal., 2014).
Country Highwaterrisk Extremelyhighwaterrisk
Rainfedarea(ha) Irrigatedarea(ha) Rainfedarea(ha) Irrigatedarea(ha)
SouthAfrica 27,788 6441 – – Swaziland – 24,790 – – Sudan – 17,443 – 2732 Tanzania 38 9520 – – Nigeria – 4415 – – Madagascar 191 1972 – 671 Somalia 61 2422 63 253 Mozambique 987 502 4 – Ethiopia 1261 153 – 2 Chad – 21 – 244 Niger – – – 163 Kenya 2 60 – –
3.4.Soilandlandmanagement
Sugarcane is grown under a wide variety of management regimes in SSA ranging from large commercial plantations to smallholderfarms.Long-termproductionofsugarcanehasbeen showntohavebothanegativeimpactonsoilpropertiesandcrop productivity (Garside et al., 2001; Meyer and Van Antwerpen, 2001)butalsoapositiveeffectwithgreencaneharvestimproving soilbiologyandnutrientcycling(Borgesetal.,2014;Trivelinetal., 2013).Themanagementsystemsonlargeplantationsgenerallyuse intensive farming methods which are often semi-mechanised, putting pressure onsoil resourcesand modifying soil physical, chemicaland biologicalproperties.Traffickingheavymachinery in-field can lead to compaction and reduced soil porosity, decreased soil aeration and increasedsoil resistance (Swinford andBoevey,1984).Thesechangesinturncanimpactnegativelyon rootgrowthandultimatelyaffectyield.Therearemoves,however, tosystemsofcontrolledtrafficking,especiallyforcaneharvesting andhaulage,which canreduce thelevelof damageinfield and contributetosignificantlyhigheryieldsandincreasedprofitability (LeclerandTweddle,2010).Smallholdersystemstendtobeless mechanised, but can nevertheless also be detrimental to soil conditions,for instancedue tosoil erosioncaused bya lackof appropriateconservationmeasures.
Continuouscroppingwithsugarcanehasbeenshowntoleadto increasedsoil acidification, nutrient depletionand reduced soil microbial activity and biomass (Table 3) compared to other agriculturallandusesornaturalvegetation,although studiesin Mauritius (Mardamootoo et al., 2010) identified elevated soil phosphorusresultingfromyearsofoverapplicationoffertiliser. Soilcarboncontentandsoilmicrobialactivitytendstodeclinewith long-termsugarcanecultivationcomparedtonaturalvegetation andotheragriculturalsystems.
3.5.Greenhousegasemissions
Greenhouse gas emissions are associated with all crop production activities, and for sugarcane arise through field management,fertilizationandespeciallyburningpriortoharvest (Table3).However,thedegreetowhichconversiontosugarcane changesemissionsdependsonthenetemissionsoftheprevious landuse.Wherenaturalforestshavebeenconvertedtosugarcane net emissions may increase, while the replacement of other agriculturallanduseswithsugarcanecanresultinanetdecreasein emissions(Bordonaletal.,2015).
Process-based physical models that represent interactions between the landscape and the overlying atmosphere indicate thatdirect,biogeophysical(e.g.,duetoalbedo)changesassociated
Table3
Summaryofreportedimpactsassociatedwithsugarcaneproductiononwater,soilandairqualitybystudylocation.
Receptor Impact Location Source
Surfacewaterbodies Increasednutrientsconcentrationinrunoff Mauritius NgKeeKwongetal.(2002)
Florida,USA Riceetal.(2002)
Uganda Munabietal.(2009)
SouthAfrica VanderLaanetal.(2012)
Queensland,Australia FaithfulandFinlayson(2005),
Mitchelletal.(2005)
Louisiana,USA Yuetal.(2008)
Increasedpesticidesandherbicides Queensland,Australia Mülleretal.(2000),
Mitchelletal.(2005),
Camenzulietal.(2012),
Davisetal.(2013)
Increasedsuspendedanddissolvedsolids Swaziland Mhlangaetal.(2006)
Queensland,Australia Rothetal.(2003),
FaithfulandFinlayson(2005)
Louisiana,USA Yuetal.(2008)
Increasedsalinity Swaziland Mhlangaetal.(2006)
Groundwaterbodies Increasednutrientconcentrations Queensland,Australia Rasiahetal.(2005),
Rasiahetal.(2013)
Soil Acidification SouthAfrica Schroederetal.(1994)
PapuaNewGuinea Hartemink(1998a,b)
Elevatedphosphorusstatus Mauritius Mardamootooetal.(2010,2012,2013)
Nutrientdepletion PapuaNewGuinea Hartemink(1998b)
Fiji Masilacaetal.(1986)
Reducedmicrobialactivity/biomass Brazil Sant’Annaetal.(2009),
daSilvaetal.(2012),
Souzaetal.(2012)
SouthAfrica Dominyetal.(2002),
Haynesetal.(2003)
Queensland,Australia HoltandMayer(1998),
Stirlingetal.(2010),
Brackinetal.(2013)
Reducedsoilcarbon Brazil CerriandAndreux(1990),
Silvaetal.(2007),
Sant’Annaetal.(2009)
SouthAfrica Dominyetal.(2002),
Haynesetal.(2003)
Fiji Masilacaetal.(1986)
Reducedsoilloss Brazil Macedo(2007)
Air Greenhousegasemissions Brazil Bordonaletal.(2015)
Australia Denmeadetal.(2010)
Pollution Brazil Tsaoetal.(2012)
Localclimatechanges Brazil Loarieetal.(2011),
withconversion ofannual toperennialcropscanbeatleastas importantasbiogeochemicaleffects(Georgescuetal.,2011)and conversion to sugarcane can impact on local climate. The replacementof shallowwithdeeperrootingsystemsassociated withperennialbioenergycropdeploymentcanleadtodepletionof waterwithinthesoilcolumn,modificationofthewatertable,and consequentialeffects for regional hydroclimate.Significant and rapid warmingmay occur after sugarcaneharvest, which may graduallybeoffsetasthecropreachesmaturity(Georgescuetal., 2013).
4.Socialimpacts
Thespatialconcentrationandcloseproximityofcane produc-tionareastoprocessingplantsmeansthatintermsofemployment andlocaleconomiceffects,thefootprintofsugarproductioncanbe relativelysmallbutverydeep.Beyondanestate-factorycomplex, thespatial linkbetweena groupof cane growers and a single factorycreatesastrongdependency:sugarcanegrowers,whether largeorsmall,seldomhaveanychoiceastothefactorytowhich theysendtheircane.Thismeansthattherelationshipsbetween farms,factory,workforceandthelocaleconomycanbeverytightly coupled. The main social impacts are thus evident through employmentandlivelihoods,foodsecurityandlandavailability, andhealth.
4.1.Employmentandlivelihoods
The most significant direct social impact associated with sugarcaneproductionarisesthroughtheemploymentitgenerates. AcrossSSAthousandsofindividualsareemployeddirectlyonsugar estatesand inmills, while otherswork as, and for,outgrowers (independentfarmerscontractedtogrowsugarcaneontheirown landtosupplytomillsand/orestates)andintheprovisionofthe manygoodsandservicesthatsupportsugarproduction.Earnings fromsugarcaneindirectlysupportmanyotherlocalbusinessesand small-scale economic activities. Unfortunately, there are no current comprehensive and robust estimates of the levels and typesofemploymentassociatedwithsugarcaneproductionand processing in SSA. The South Africa Sugar Association (SASA) estimatesthat79,000direct jobsand 350,000indirectjobsare associatedwithproductionandprocessinginSouthAfrica(SASA, 2014).If this estimate is both correct and representative, then projectingonthebasisofjobspertonofsugarproducedwould suggestthattheremaybeasmanyas1.8millionjobsassociated withtheindustryinSSA.
Whilst workingconditions of employees varytremendously, manualcane cutting isknown tobeparticularly arduous, with somecuttersinthepastbeingtreatedbrutally.WhilstRobinsetal. (1998)reportedthat14%ofworkersinsugarcanefieldsinSouth Africain1998werephysicallyabusedbyfarmmanagementstaff, modernlabourregulationshavedramaticallyimproved employer-employeerelations.Ontheotherhand,withinthesouthernAfrica sugar industry there is increasing casualization of labour associatedwithindustryrestructuring,changingaidframeworks andmarketincentives,andmechanisation(OxfamInternational, 2004; Richardson, 2010; Richardson-Ngwenya and Richardson, 2014). Casualization and seasonal employment, with labourers beingrepeatedlyhiredonshort-termcontracts,seasonalabsolve employersofresponsibilityforprovidingbenefitssuchaspension contributions,healthandsocialservicesandemploymentsecurity, andalsogreatlyincreasesthechallengesassociatedwith establish-ing and maintaining representation through labour unions (Richardson-Ngwenya and Richardson, 2014). In Brazil, human rightsconcernsandpressuretoreduceburningpriortoharvest
havehastenedtheshifttomechanicalharvesting,thusreducing theindustry’sdemandforlesseducatedlabour.
Therangeofskillsneededtosupportsugarcaneproductionis reflectedinwageandsalarylevels.However,thereisnoevidence that allows a systematic analysis of earnings in comparison to otheragro-industries.OxfamInternational(2004) reportedthat salaries on plantations in Mozambique were very low, and, accordingtotradeunionsandcertaincivilsocietyorganisations, didnotconstitutealivingwage.Nevertheless,thesamereportalso noted that jobs in the sugar industry were highly valued and consideredbetterthanavailablealternatives.Thisisreflectedin thefactthatsincetherehabilitationoftwosugarmillsinSofala Province,employment rateshaddoubledandpovertyrateshad changed from being thehighest in the country, tothe lowest.
Herrmann and Grote (2015) found that plantation workers in Malawiwerebetteroffthannon-participants;however,whilethey wereableavoidextremepoverty;theydidnotearnenoughtorise above the poverty line. As noted earlier many mills provide services likeclinics and schools, which are thoughtto play an importantroleinattractinganddisciplininglabour.
Althoughnotformalemployees,outgrowersandindependent cane producers are integral to the sugar industry in SSA and representanotherchannelthroughwhichtheindustryimpactson localeconomies.Whilstmanyoutgrowerschemesfocuson small-scale producers, it is important to remember that in some countries like South Africa, there are some very large and technicallysophisticatedindependentcanegrowers.
Many studies have identified positive effects of outgrower schemesonincomesandpovertyratesofsmallholders,butsome havewarnedofnegativeenvironmentalimpactsassociatedwith pooragriculturalpractices (Clancy, 2008).Herrmannand Grote (2015)reportedthatinMalawitheincomesofoutgrowers’were significantlyhigherthanthoseofnon-outgrowers,theoutgrowers hadsignificantlylowerpovertyindices.Highincomelevelswere alsoreportedfortheKaleyaoutgrowerschemeinZambia(Shumba etal.,2011).In contrast,Richardson(2010)notedhighlevelsof indebtednesssomeoutgrowersfaceduetohighcapitalinvestment costs,particularlyforirrigation(Tyler,2008).Fromtheirworkin Malawi,Richardson-NgwenyaandRichardson,(2014)suggestthat animportant“hiddenbenefit”ofsmall-scalesugarproductionis accesstoirrigationandelectricityinfrastructure,withcanalsobe usedforfoodcropproductiontoincreasefoodsecurity.Itwouldbe wrong to assume that outgrowers and other small-scale cane producers will necessarily be a prominent feature of cane production throughout Africa. Dubb(2015) provides a detailed andspatiallysituatedpoliticaleconomyanalysisoftheon-going decline of small-scale sugar cane production in the Umfolozi regionofSouthAfrica.
The mixed evidence on economic and social impacts for outgrowersreflectsthecomplexandchangingpoliticaleconomy withinthesugarindustryoperates,thefundamentally asymmet-ricalpowerrelationsbetweenestates/millsandoutgrowers,and thequalityofschememanagement(Church,2008).
4.2.Foodsecurityandland
Giventhemixedrecordofsmall-scale outgrowerschemesit should not be surprising that some researchers have raised concernsaboutnegativeeffectsonthefoodsecurityofoutgrower households. This echoes earlier debates regarding potential negative effects on food security when smallholders devote a significantproportionoftheirlandtocashorcommercialcrops.
TerryandRyder(2007),forexample,suggestedthatoutgrowersin Swaziland,andparticularlythepoorerones,wereunabletomeet theirfoodrequirementsafterconvertingalltheirlandtorainfed sugarcane.WiththeMumiassugarschemeinKenya,concernwas
expressedthatashifttocanebysmall-scaleproducerscouldresult inincreasedfoodinsecurity(Tyler,2008).Specifically,womenlose accesstolendforfoodcropsandwouldalsohavelesscontrolover householdincome. Nevertheless,Kennedy (1989) couldfindno evidence that sugarcane production was associated with an increaseinmalnutrition.Movingupfromindividualoutgrowers levelandtheirhouseholds,someanalystsandadvocatesarguethat thereisatrade-offbetweennationalfoodsecurityontheonehand andexpansion of thesugarindustry ontheother.Thegrowing interestinbiofuelsandthesugarindustry’srequirementsforhigh qualitylandandwaterresourceshavemadesugarcentraltorecent debatesaroundlandandwaterdealsinsouthernAfrica(Thaler, 2013;Borrasetal.,2011;Richardson,2010;Shumbaetal.,2009). Landaccessandtenureareperhapstwoofthemostimportant issues affecting smallholder livelihoods. Given the increasing pressureonagriculturalandgrazinglandthroughoutSSA(Jayne etal.,2014),expansionofsugarcaneproductionwilllikelyhave significantimplicationsforsomelocalresidents.InmanyAfrican countries, land is under customarytenure, and negotiations to secure land for large-scale projects, like sugar estates, can be fraught.Cotulaetal.(2008)concludedthatnegotiationsoftentook place on an unequal footing: corruption, local inhabitants not knowing the commercial value of their land, a lack of legal knowledgeand locallevelpoliticsandpowerrelationsallcome intoplay.Evenwithawell-negotiateddeal,companiescanfailto complywithagreedterms.
BothThaler (2013) and Borraset al. (2011) focus on a high profile‘landgrab’byaBritishcompanythatproposedtoproduce ethanol and sugarcane on a new 30,000-ha plantation in Mozambique.Thecompanyhad apparentlynegotiatedwiththe localcommunity,butdidnotrespecttheagreement,andbeganto encroach on people’s land. Thousands of people were to be displaced.Theprojectdidnotproceedforfinancialreasons,which turnsouttobeaverycommonoutcomeforplannedlarge-scale landdevelopments.Nevertheless,thisdevelopmentwasinstark contrasttotheMozambicanPresidentArmandoGuebuza’swords “biofueldevelopmentwillnotdislodgeMozambicanfarmersfrom theirlands”(Borrasetal.,2011,p.217).Otherinstancesoflarge displacementsofpeopledueto‘landgrabs’forsugarproduction have also been documented. For example, Richardson (2010)
reportedonthecaseof1100householdsdisplacedinMozambique asaresultoflandandwatergrabbingbysugarcanecompanies.
Thelandandwaterrequirementsfornewsugarcane develop-mentputanexpandingindustryonacollisioncoursewithAfrica’s small-holder dominated and increasingly land-hungry agrarian economies. The sugar industry might both contribute to and benefit from the structural transformation of these agrarian economiesthatmanyobserversargueissobadlyneeded.Itwill, however, essentiallyrespond to international capital and com-moditymarkets,andevolvingtradingregimes,withthelivelihoods ofruralAfricansbeingasecondaryconcern.
Finally,theimpactsonfoodsecurityarisingfromlinksbetween sugarcaneandbiofuelsareanissuethatoftenengendersnegative publicreactionandanareawheresciencecouldinformviewpoints anddecision-making.Whilstaimedprincipallyatbiofuel assess-ment, the Bioenergy and Food Security Analytical Framework (BEFS)developedbytheFAO(2010)couldalsoprovideusefulnew insightsregardingsugarcaneasacommoditycrop.Forexample,
Felixetal. (2010)usedtheBEFS frameworktoevaluate biofuel productionoptionsinTanzania,comparingbenefitsandtrade-offs betweendifferentgrowers(smallholderfarmersandcommercial farmers).Arndtetal.(2010)usedtheBEFSframeworktoevaluate long-termbiofueldevelopmentimplicationsinMozambiqueand Tanzaniain terms of supporting growth, reducing poverty and labour transfers between intensive cash cropping and biofuel feedstocks.
4.3.Health
ThevastmajorityofsugarcaneinAfricaisburnedbeforeharvest toremove extraneous cane material (Watson et al.,2008).The directimpactsofthisontheenvironmentareevidentthroughthe amountofatmosphericpollutantsemitted.Researchhasshown that pre-harvestburning isthecauseof majorhealth problems relatedtolungfunctionandtherespiratorysystem(Arbexetal., 2014).Theriskofmutagenicityrelatedtosugarcaneburningand developmentofcacogenicsymptomshasalsobeenraised(Prado etal.,2012;Sisenandoetal.,2012).InBrazil,Ribeiro(2008)found that burning of sugarcane fields was particularly harmful to plantationworkers,exposingthemtogreaterrisksoflungcancer. There has been some attention given to the links between sugarcaneproductionandmalaria,Ghagas’diseaseand schistoso-miasis(Phoolchund,1991).Dusfouretal.(2010)linkedtheuseof pesticidesinsugarcanefieldstheincreasingresistanceofmalaria vectors in neighbouring wetlands. In Zambia, labourmigration associated with sugarcane has been associated with a 16–22% increaseinHIVinfection(Richardson,2010).Otherhealthissues includethephysicalandergonomicstressesassociatedwithcane cutting over extended periods, and risk of disease from the cramped and poor quality of housing provided to plantation workers (Richardson, 2010). Conversely, there are many sugar estatesinSSAthatprovidehealthcarefacilitiesforbothemployees andlocalresidents.
5.Concludingcommentsandawayforward
Fig.4outlinesthekeyenvironmentalandsocialchallengesfor sugarcaneproductionandtheirinter-dependencies.Sugarcanehas beenanintegralpartofAfricanagricultureforcenturiesundera variety of socio-technical and environmental conditions and through a diversity of production scales and systems. A major implication of this is that any meaningful discussion of the economicandsocialimpactsandenvironmentalsustainabilityof caneproductionmustthereforebecontextspecific.Thescientific literature provides numerous examples wherethe water,social and environmental impacts of cane production is directly dependent onthe qualityof scheme,nature of the production system and farm management. Good agricultural management practices can reduce losses of herbicide (Masters et al., 2013), nutrients (Thorburn et al., 2011) and atmospheric pollutants (Weier,1996,1999;Macedoetal.,2008;Allenetal.,2010;Signor etal.,2013);carbonsequestrationcanbeincreased(LaScalaetal., 2006);and theimpacts ofburning canbesignificantlyreduced whenthecropisharvested“green”(Galdosetal.,2009;Eustice etal.,2011;AnayaandHuber-Sannwald,2015).Caneproduction,in general, is neither explicitly good nor bad, sustainable nor unsustainable.Thissuggestsacriticalroleformulti-disciplinary, multi-scaleanalysisandplanningasafoundationforanyfurther expansion ofthesector.Thiskindof integratedanalysiswillbe particularly importantin relationtoboth waterandlivelihoods withineconomicdevelopmentcorridors.
InSSAsugarcanbeproducedrelativelycheaply,whichmightbe expectedtoleadtoanexpansionofproduction.However,ifthe predictedchangestotheEUsugarmarketcametopass,onlythe mostcompetitivesugarproducersinSSAwillbeabletocontinue sellingtoEurope,whileotherswillneedtoorientthemselvesmore towardsregionalandexternalsugarmarketsand/ortheemerging biofuelmarket.KalindaandChisanga(2014)suggestthatZambia couldexportitssugarwithintheSADCratherthantoEurope,since thehighfreightcostsitincursasalandlockedcountry(upto45%of theexportprice)meanitcouldsellitssugarmoreprofitablyover shorterdistances.Nigeriaiscurrentlyembarkingonaprogramme aimedatproducing1.8 Mt/yearandbecoming self-sufficientby
2022. However, the Nigerian Sugar Master Plan contains a significant component of ‘backwards integration' which will requirerefinerieshaving toinvestin sugar productionin order toretainlicences(Lichts,2016).InAngola,withtwomegasugar projectsaresettoboostsouthernAfrica’ssugarproductionby15% by2020(SADC, 2013;Jolly, 2012).LargemarketssuchasIndia, which has become a net importer of sugar (Hall, 2012), will undoubtedlyalsobecomemoreimportant.
Aconsequenceofthehighlyvariableclimateandcurrentlackof irrigationinfrastructuremeansthatSSAisparticularlyvulnerable toclimatechange (Callaway 2004; Knox et al., 2013) withthe southern region being perhaps most vulnerable (IPCC, 2014). Amongtheprojectedeffectsofachangingclimate,changesinthe watercycleandwaterresourcesavailabilityareoftenhighlighted as major problems facing sustainable development in SSA (Kusansgayaetal.,2014).Furthermore,mostplanned,large-scale agriculturaldevelopmentsarerelianttosomeextentonirrigation to ensure crop water demands are met through the growing season,thusaimingtoachievethepotentialyieldofferedbyother biophysicalconditions.Thus,theavailabilityofwaterforirrigation is a critical constraint on sugarcane expansion and where developmentis intended, itspotential impactonthat resource must be considered carefully. It seems inevitable that future developmentswillincreasinglydependonirrigationabstraction giventhepotentialforyieldupliftandtocopewithfuturerainfall uncertainty(Knoxetal.,2010).However,itis alsoimportant to recognise the uncertainty in assessing climate impacts on productivity; some studies investigating rainfed production suggesttheimpactsonfutureyieldcouldbemuchlessdramatic, bothinSouthAfrica,AustraliaandBrazil(Singelsetal.,2013;Marin etal.,2013).
ItisevidentthatsugarcaneinSSAcanbehighlyproductive; howeverexpansionisdependentuponthecostenvironmentand marketopportunitiesbeingfavourable.Fromapolicyperspective,
becauseofitsrequirementsforandassociationwithinfrastructure development,thesugarindustryisseentohaveapivotalroleina numberofthegrowthcorridors.Infrastructuredevelopment,such astheconstructionofreservoirs,roads,pipelinesandelectricity hasbeenshowntohavepotential positivesocial andeconomic impacts (Knox et al., 2013)well beyond sugarcane production. Opportunitiesforemploymentgenerationthroughamodernsugar industry are but one attraction. However, the industry faces a numberofsignificantbusinessrisksincludingtheneedforhigh levelsofcapitalinvestmenttosupportlanddevelopment,mainly forirrigationandmillinginfrastructure.Inaddition,requirements forcapitalinvestmentintransportationandpowernetworks,and establishmentoflocalsocialservices(housing,schools,hospitals), areconsiderable.Riskarisesfromthefactthatcaneisaperennial cropgrownasamonoculture,andwithlong-termcontractstying growers tomills thereis littleroomforadaptationtochanging conditions. For example, the SSA sugarcane sector is also increasinglyexposed tocompetitionfromimportsof sugarand risks associated with changes in international markets. Given competing demands for agricultural land from other crops includinghighvaluefruitandvegetablesforexportmarkets,the balanceofrisk-rewardforthesugarcanesectorinSSAisbecoming moreuncertain.
Sugarcaneproductionatanysignificantscalewillalsoaffectthe availabilityoflandforotheruses,competingwithfoodcropsand natural ecosystems. Environments with suitable growing con-ditionsfor sugarcane, suchasfavourable soils, agroclimateand topography,aswellasaccesstosufficientreliablesuppliesofgood qualitywaterforirrigation,arebecomingincreasinglyscarce.Like otherrowcrops,theadoptionofmodernwater-savingirrigation technologiesis oftencitedasbeingkeytoincreasingwateruse efficiencywhilemaintainingcurrentlevelsofproduction. Howev-er, new technology requires greater capital investment, so irrigatorsareoften reluctanttoadoptnewsystems unlessthey
canbeconvincedofthelikelybenefits.Wherewatercostsarelow, sugarcanegrowershavelittleincentivetoswitchtechnology to improveefficiencyunlessotherexternalitiesinfluencetheirability tomaximisenetcropreturn.However,risingenergy,labourand watercosts,coupledwithaneedtoincreasewaterproductivity due to increasing competition for limited resources are now drivingforcesinfluencingtechnologychoiceincaneproduction.If irrigatedsugarcaneistobesustainable,theoverridingissueswill betoimprovedrainagemanagementforeffluentcontrol(toreduce excess water losses, the leaching of salts, agrochemicals and nutrients)andtheneedtomaximisewaterproductivity(Carrand Knox,2011).
Infrastructure, markets and water availability are current concerns for agricultural and rural development they are importantbutinnowayuniquetothesugarindustry.However, whatis uniqueis thehighenvironmental, economicand social impactsassociatedwithsugarcane,thesmallbutdeepfootprint that arises essentially from its high spatial concentration. The experiencetodateinSSAsuggeststhattheseimpactscanbeeither positiveornegative,dependingontheenvironment,the produc-tion model, and perhaps most importantly, the quality of management. It is not so much a question of whether large estatesarebetterthanoutgrowerschemesorwhethernewhybrid businessmodelsthatcombinesmall-scaleagriculturewith large-scaleplantationsshouldbepursued(Sulleetal.,2014;Dubb,2015). Rather,theresearchchallengeistounderstandbetterhowthese differentmodelsmight beused in differentcontexts todeliver moresustainableandmoreequitableeconomicgrowth.Thewide array of forms that exist thus present a number of important opportunitiesforresearch,includinganeedtounderstandwhich patternsofproductionaremostcommon,thereasonsunderlying theirgeospatialvariationandthefactorsthatmostinfluencetheir determination.
Morebroadly,itiscriticaltoacknowledgethedangerofpolicy narratives that portray SSA as possessing an abundance of underutilised agricultural land that with corporate investment couldbecomethenextglobalfoodandcommoditiesbasket.The currentinterestindevelopmentcorridorsinsouthernandeastern Africais supportedbythesenarratives, anditis possible–and perhapstooeasy–totiethesugarindustrytothemandtheglobal and corporate agriculturalfutures that they both envisageand promote.Analternativenarrativemightberootedlocallyrather thanglobally,andportraythesugarindustryaskeydriveroflocal and sustainable environmental management and economic growth. The differences between these two visions essentially comedowntothepoliticsofcapital,land,waterandemployment. Howthesepoliticsplayoutinparticularcontextswilldetermine whoultimatelyexperiencestheexpansionofthesugarindustryin SSAasasweetdeal.
Acknowledgements
ThisresearchformspartoftheTHESISprojectfundedthrough BelmontForumprogrammeongloballandusechangeandfood security. The authors are grateful to their respective national funding research councils and agencies for supporting this research.The authorsacknowledgefundingfromtheUK(NERC NE/M005259/1), the USA (NSF grant EAR-1204774) and Brazil (FAPESP).Enquiriesforaccesstothedatareferredtointhisarticle shouldbedirectedtoresearchdata@cranfield.ac.uk.
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