Table Of ContentFood security and environmental conservation are David J. Connor is Emeritus Professor of aC
two of the greatest challenges facing the world Agriculture at The University of Melbourne, no
dn CROP ECOLOGY
today. It is predicted that food production must Australia. His research programs deal with n
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increase by at least 70% before 2050 to support land and environmental relationships of ao
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continued population growth, although the size of a range of irrigated and rainfed cropping s,
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the world’s agricultural area will remain essentially systems. mo
unchanged. Robert S. Loomis is Emeritus Professor in the ao
This updated and thoroughly revised second Department of Plant and Environmental nm Productivity and Management in Agricultural Systems
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edition provides in-depth coverage of the impact Sciences at the University of California, s
of environmental conditions and management on Davis, USA. His research interests include
crops, resource requirements for productivity, and photosynthetic productivity, nutrient and
C SECOND EDITION
effects on soil resources. The approach is explanatory water management, and integrated
and integrative, with a firm basis in environmental simulation models. R
physics, soils, physiology, and morphology. System Kenneth G. Cassman is Professor of
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concepts are explored in detail throughout the book, Agronomy at the University of Nebraska,
giving emphasis to quantitative approaches, man- USA. His research focuses on nutrient cycling
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agement strategies and tactics employed by farmers, and crop nutrient requirements, crop yield
and associated environmental issues. potential, and water productivity of
Drawing on key examples and highlighting the irrigated crops. E
role of science, technology, and economic conditions
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in determining management strategies, this book is
suitable for agriculturalists, ecologists, and environ- O
mental scientists.
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“Any practitioner or student of ‘evidence-based agriculture’ needs a copy of this O
book.” R. Ford Denison, University of Minnesota
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“… a timely update of a foundational text for college or graduate curricula… This
book is remarkably easy to read and will be accessible to a range of knowledge
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levels and backgrounds.” Sylvie M. Brouder, Purdue University
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Cover illustration (front): ancient cereal landscape, Soria,
Spain. © D. Connor; (back, left): women transplanting
David J. Connor, Robert S. Loomis
rice, Mauritania. © H. Gómez Macpherson; (back, right):
soybean harvest, Brazil. © D. Connor.
and Kenneth G. Cassman
CropEcology
ProductivityandManagementinAgriculturalSystems
SecondEdition
Foodsecurityandenvironmentalconservationaretwoofthegreatestchallengesfacing
the world today. It is predicted that food production must increase by at least 70%
before 2050 to support continued population growth, although the size of the world’s
agriculturalareawillremainessentiallyunchanged.
Thisupdatedandthoroughlyrevisedsecondeditionprovidesin-depthcoverageofthe
impactofenvironmentalconditionsandmanagementoncrops,resourcerequirementsfor
productivity,andeffectsonsoilresources.Theapproachisexplanatoryandintegrative,
withafirmbasisinenvironmentalphysics,soils,physiology,andmorphology.System
concepts are explored in detail throughout the book, giving emphasis to quantitative
approaches, management strategies and tactics employed by farmers, and associated
environmentalissues.
Drawingonkeyexamplesandhighlightingtheroleofscience,technology,andeco-
nomicconditionsindeterminingmanagementstrategies,thisbookissuitableforagri-
culturalists,ecologists,andenvironmentalscientists.
David J. Connor is Emeritus Professor of Agriculture at the University of Melbourne,
Australia. His research programs deal with land and environmental relationships of a
range of irrigated and rainfed cropping systems. In 2003 he was awarded the Donald
MedalforoutstandingcontributionsbytheAustralianSocietyofAgronomy.
RobertS.LoomisisEmeritusProfessorintheDepartmentofPlantandEnvironmental
Sciences at the University of California, Davis, USA. His research interests include
photosyntheticproductivity,nutrientandwatermanagement,andintegratedsimulation
models.Heholdsnumeroushonorsfromscientificsocietiesanduniversitiesworldwide.
Most recently, in 2001, he was awarded Douter honoris causa, Universidade Te´cnica,
Lisboa.
KennethG.CassmanisProfessorofAgronomyattheUniversityofNebraska,USA.His
researchfocusesonnutrientcyclingandcropnutrientrequirements,cropyieldpotential,
andwaterproductivityofirrigatedcrops.In2006hereceivedtheAgronomicResearch
AwardfromtheAmericanSocietyofAgronomy.
Crop Ecology
Productivity and Management in
Agricultural Systems
SecondEdition
DAVID J. CONNOR
UniversityofMelbourne,Australia
ROBERT S. LOOMIS
UniversityofCalifornia,Davis,USA
KENNETH G. CASSMAN
UniversityofNebraska,Lincoln,USA
CAMBRIDGEUNIVERSITYPRESS
Cambridge,NewYork,Melbourne,Madrid,CapeTown,
Singapore,Sa˜oPaulo,Delhi,Tokyo,MexicoCity
CambridgeUniversityPress
TheEdinburghBuilding,CambridgeCB28RU,UK
PublishedintheUnitedStatesofAmericabyCambridgeUniversityPress,NewYork
www.cambridge.org
Informationonthistitle:www.cambridge.org/9780521761277
(cid:2)C D.J.Connor,R.S.LoomisandK.G.Cassman2011
Thispublicationisincopyright.Subjecttostatutoryexception
andtotheprovisionsofrelevantcollectivelicensingagreements,
noreproductionofanypartmaytakeplacewithoutthewritten
permissionofCambridgeUniversityPress.
Firstpublished2011
PrintedintheUnitedKingdomattheUniversityPress,Cambridge
AcataloguerecordforthispublicationisavailablefromtheBritishLibrary
LibraryofCongressCataloguinginPublicationdata
Connor,D.J.
Cropecology:productivityandmanagementinagriculturalsystems/DavidJ.Connor,RobertS.Loomis,
KennethG.Cassman.–2nded.
p. cm.
Rev.ed.of:Cropecology/R.S.Loomis,D.J.Connor.1992.
Includesbibliographicalreferencesandindex.
ISBN978-0-521-76127-7(hardback)–ISBN978-0-521-74403-4(paperback)
1.Agriculturalecology. 2.Agriculturalsystems. I.Loomis,R.S. II.Cassman,KennethG.
III.Loomis,R.S.Cropecology. IV.Title.
S589.7.L66 2011
630.2(cid:3)77–dc22 2010053580
ISBN978-0-521-76127-7Hardback
ISBN978-0-521-74403-4Paperback
CambridgeUniversityPresshasnoresponsibilityforthepersistenceor
accuracyofURLsforexternalorthird-partyinternetwebsitesreferredto
inthispublication,anddoesnotguaranteethatanycontentonsuch
websitesis,orwillremain,accurateorappropriate.
Contents
Preface pagexi
PartI Farmingsystemsandtheirbiologicalcomponents 1
1 Agriculturalsystems 3
1.1 Onthenatureofagriculture 3
1.2 Unifyingthemes 8
1.3 Maintenanceofagriculturalsystems 20
1.4 Reviewofkeyconcepts 21
2 Trophicchains 23
2.1 Plantproduction 23
2.2 Trophicsystemsinagriculture 27
2.3 Animalandhumannutrition 30
2.4 Carryingcapacity 39
2.5 Reviewofkeyconcepts 42
3 Communityconcepts 44
3.1 Communitychange 44
3.2 Biomassaccumulation 45
3.3 Responsestocrowdinginmonocultures 53
3.4 Competitioninpolycultures 58
3.5 Communityresponsetolimitingfactors 66
3.6 Reviewofkeyconcepts 69
4 Geneticresources 71
4.1 Geneticdiversityinagriculture 71
4.2 Changeingeneticstructure 74
4.3 Cultivardevelopment 81
4.4 Geneticadvanceandmaintenanceofdiversity 88
4.5 Reviewofkeyconcepts 94
vi Contents
5 Development 96
5.1 Developmentaltime 96
5.2 Developmentalswitches 100
5.3 Quantifyingphenologicalresponse 106
5.4 Seedgerminationanddormancy 112
5.5 Cropimprovement 118
5.6 Reviewofkeyconcepts 121
PartII Physicalandchemicalenvironments 123
6 Aerialenvironment 125
6.1 Radiationconcepts 125
6.2 TheSWsource 128
6.3 Sun–Earthgeometry 129
6.4 SWpenetrationoftheatmosphere 131
6.5 Radiationbalance 134
6.6 Energybalance 137
6.7 Turbulenttransport 142
6.8 Advection 146
6.9 Microclimate 148
6.10 Climateandweather 150
6.11 Keyconcepts 156
7 Soilresources 159
7.1 Soilchemistry 159
7.2 Soilformation 162
7.3 Soiltypesanduses 171
7.4 Soilproperties 173
7.5 Waterandaircomponents 181
7.6 Soiltemperaturerelations 187
7.7 Reviewofkeyconcepts 190
PartIII Productionprocesses 193
8 Nitrogenprocesses 195
8.1 Thenitrogencycle 195
8.2 Decayandimmobilization 200
8.3 Mineralizationandnitrification 202
8.4 Lossofnitrogen 203
8.5 Assimilationofmineralnitrogenbyplants 207
8.6 Nitrogenfixation 208
8.7 Examplenitrogencycles 214
Contents vii
8.8 Farmingwithorganicsourcesofnitrogen 219
8.9 Reviewofkeyconcepts 226
9 Waterrelations 229
9.1 Flowofwaterthroughacrop 229
9.2 Evapotranspiration 232
9.3 Collectionofwaterbyrootsystems 237
9.4 Amodelofcropwaterbalance 241
9.5 Responsesofcropstowatershortage 243
9.6 Adaptationtodrought 244
9.7 Water-useefficiency 257
9.8 Reviewofkeyconcepts 260
10 Photosynthesis 262
10.1 Photosyntheticsystems 262
10.2 Leafphotosynthesis 265
10.3 Canopyphotosynthesis 276
10.4 Modelingcanopyphotosynthesis 280
10.5 Canopystructureforproductivityandcompetitiveness 283
10.6 Reviewofkeyconcepts 289
11 Respirationandpartitioning 292
11.1 Carbonuseinrespirationandsynthesis 292
11.2 Growthrespirationandgrowthyield 296
11.3 Seasonalpatternsofcroprespiration 300
11.4 Morphologicalaspectsofpartitioning 302
11.5 Ideotypeconcepts 314
11.6 Reviewofkeyconcepts 317
PartIV Resourcemanagement 321
12 Soilmanagement 323
12.1 Spatialvariability 323
12.2 Plantnutrition 325
12.3 Managementofsoilfertility 330
12.4 Fertilizerpractices 334
12.5 Tillagesystems 341
12.6 Drainage 346
12.7 Erosion 348
12.8 Landvalueandcapability 354
12.9 Reviewofkeyconcepts 356
viii Contents
13 Strategiesandtacticsforrainfedagriculture 358
13.1 Agricultureinwetregions 358
13.2 Principlesforefficientuseofwater 360
13.3 Patternsofwatershortageandcroptypes 360
13.4 Optimumpatternsofwateruse 361
13.5 Cultivarsandsowingtime 365
13.6 Croprotationsandfertilizer 367
13.7 Densityandplantingarrangement 369
13.8 Fallow 371
13.9 Simulationmodelsandanalysesofcroppingstrategies 374
13.10 Reviewofkeyconcepts 382
14 Watermanagementinirrigatedagriculture 384
14.1 Irrigationandworldfoodsupply 384
14.2 Waterandsalt–aninescapablecombination 385
14.3 Salinityandalkalinity 386
14.4 Efficienciesofwateruseinirrigation 391
14.5 Wateruseandproductivity 391
14.6 Irrigationmethods 393
14.7 Irrigationscheduling 401
14.8 Managementofwatersupplyanddrainage 404
14.9 Selectionofareasforirrigationschemes 408
14.10 Reviewofkeyconcepts 409
15 Energyandlabor 411
15.1 Sourcesandutilizationofenergy 411
15.2 Energyinfoodproduction 413
15.3 Improvingefficiencyofenergyuse 419
15.4 Low-inputfarming 423
15.5 Cropsforenergy 425
15.6 Reviewofkeyconcepts 433
PartV Farmingpast,present,andfuture 437
16 EvolutionofwheatproductionsystemsinsouthernAustralia 439
16.1 ThewheatbeltofNorthwestVictoria 439
16.2 Evolvingsystems 441
16.3 Initialdevelopment(1840to1900) 442
16.4 Anearlyrecovery(1900to1950) 443
16.5 Ley-farming(1950to1985) 444
16.6 Intensificationanddiversification(1985topresent) 446
16.7 Searchingfornewdesigns 451
Contents ix
16.8 Roleofsociety 455
16.9 Reviewofkeyconcepts 456
17 Technologicalchangeinhigh-yieldcropagriculture 458
17.1 Commonfeaturesofhigh-yieldsystems 458
17.2 Maize–soybeancroppingsystemsintheNorthAmericanCornBelt 459
17.3 IntensivericecroppingsystemsofAsia 470
17.4 Soybean-basedcroppingsystemsinNorthernMatoGrosso,Brazil 476
17.5 Thefutureofhigh-yieldcropagriculture 481
17.6 Reviewofkeyconcepts 482
18 Thefutureofagriculture 484
18.1 Populationandneedforfood 484
18.2 Foodproductionsince1940 490
18.3 Immediatechallenges 493
18.4 Theimportanceofatechnologicalagriculture 497
18.5 Improvingtechnology 501
18.6 Reviewofkeyconcepts 508
Specieslist 511
Conversionsandconstantsusefulincropecology 514
References 516
Index 546
