biophysical soil quality of tillage systems in conventional and organic farming

150 Pages·2015·4.75 MB·English

BIOPHYSICAL SOIL QUALITY
OF TILLAGE SYSTEMS IN
CONVENTIONAL AND
ORGANIC FARMING
Stephen J. Crittenden

BIOPHYSICAL SOIL QUALITY OF TILLAGE SYSTEMS
IN CONVENTIONAL AND ORGANIC FARMING
Thesis
by
StephenJ. CRITTENDEN
Thesiscommittee
Thesissupervisors
Prof.Dr.L.Brussaard
ProfessorofSoilBiologyandBiologicalSoilQuality
WageningenUniversity
Dr.M.Pulleman
Seniorresearcher,DepartmentofSoilQuality
WageningenUniversity
Dr.M.Heinen
Alterra,WageningenUniversityandResearchCentre
Othermembers:
Prof.Dr.S.Schrader JohannHeinrichvonThünen-Institute,
Braunschweig,Germany
Prof.Dr.Ir.S.E.A.T.M.vanderZee WageningenUniversity
Dr.Ir.W.B.Hoogmoed WageningenUniversity
Dr.G.Pérès AgrocampusOuest,INRA,Rennes,France
ThisresearchwasconductedundertheauspicesoftheC.T.deWitGraduateSchoolfor
ProductionEcologyandResourceConservation.
Front&Back: CoverphotosbyStephenCrittendenandcolleagues.
iii
BIOPHYSICAL SOIL QUALITY OF TILLAGE SYSTEMS
IN CONVENTIONAL AND ORGANIC FARMING
StephenJ. CRITTENDEN
Thesis
submittedinpartialfulfilmentoftherequirementsforthedegreeofdoctor
atWageningenUniversity
bytheauthorityoftheRectorMagnificus
Prof.Dr.Ir.A.P.J.Mol,
inthepresenceofthe
ThesisCommitteeappointedbytheAcademicBoards
tobedefendedinpublic
onWednesdaythe9thofDecember2015
at08:30intheAula.
iv
StephenJ.Crittenden
Biophysicalsoilqualityoftillagesystemsinconventionalandorganicfarming,138pages.
Thesis,WageningenUniversity,Wageningen,NL(2015),withreferencesandsummaryin
English
ISBN0000-000
Andwhatdoesthewordqualitymean?Tomeitmeanstexture.Thisbookhaspores.
Ithasfeatures.Thisbookcangounderthemicroscope.You’dfindlifeunderglass,
streamingpastininfiniteprofusion.Themorepores,themore
truthfullyrecordeddetailsoflifepersquareinchyoucangetonasheetofpaper,
themore’literary’youare.That’smydefinition,anyway.Tellingdetail.
Freshdetail.Thegoodwriterstouchlifeoften.
-RayBradbury,Fahrenheit451

C
ONTENTS
1 Introduction 1
1.1 Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 Non-inversiontillage. . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.2 Organicfarming . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.3 Controlledtrafficfarming . . . . . . . . . . . . . . . . . . . . . . 3
1.1.4 Fieldmarginstrips. . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Soilphysicalquality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Earthworms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4 Thesisobjectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.5 Thesisoutline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Effectoftillageonearthwormsovershort-andmedium-terminconventional
andorganicfarming 7
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Materialsandmethods . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.1 Sitecharacteristics. . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.2 Experimentaldesign. . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.3 Datacollectionandanalyses. . . . . . . . . . . . . . . . . . . . . 12
2.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3.1 Short-termstudy: effectofmouldboardploughingonearthworm
populations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3.2 Medium-term study: effect of reduced tillage systems on earth-
wormpopulations . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.3.3 Relationsbetweenearthworms,management,andsoilproperties. . 20
2.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.4.1 Short-termeffectsofploughingonearthworms . . . . . . . . . . . 20
2.4.2 Medium-termeffectsofreducedtillageonearthworms . . . . . . . 22
2.4.3 Relationsbetweenearthwormsandsoilproperties . . . . . . . . . 24
2.5 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3 Earthwormassemblagesasaffectedbyfieldmarginstripsandtillageinten-
sity:anon-farmapproach 27
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.2 Materialsandmethods . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2.1 Studyarea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2.2 Experimentaldesign. . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2.3 Farmmanagement. . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.2.4 Samplingandlaboratoryanalyses . . . . . . . . . . . . . . . . . . 34
3.2.5 Statisticalanalyses. . . . . . . . . . . . . . . . . . . . . . . . . . 35
vii
viii CONTENTS
3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.3.1 Distancefromfieldmarginstrips . . . . . . . . . . . . . . . . . . 35
3.3.2 Tillagecomparison. . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3.3 Soilpropertiesandearthworms . . . . . . . . . . . . . . . . . . . 36
3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.4.1 Earthwormsinfieldmarginstrips . . . . . . . . . . . . . . . . . . 42
3.4.2 Earthwormsasaffectedbytillagesystems . . . . . . . . . . . . . . 44
3.4.3 Earthworm,soilproperty,andmanagementrelations . . . . . . . . 45
3.5 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4 Soil physical quality in contrasting tillage systems in organic and conven-
tionalfarming 47
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2 Materialsandmethods . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.2.1 Sitedescription . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.2.2 Experimentaldesign. . . . . . . . . . . . . . . . . . . . . . . . . 51
4.2.3 Soilwaterretention . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.2.4 Field-saturatedhydraulicconductivity. . . . . . . . . . . . . . . . 52
4.2.5 Soilwatercontent . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.6 Aggregatestability . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.7 Drybulkdensity . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.8 Penetrationresistance . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.9 Soilorganicmattercontentandcarbonstocks. . . . . . . . . . . . 54
4.2.10 Cropyield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.2.11 Statisticalanalysis . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.3.1 Effectoftillageonsoilwaterretention. . . . . . . . . . . . . . . . 55
4.3.2 Effectoftillageonfield-saturatedhydraulicconductivity . . . . . . 56
4.3.3 Effectoftillageonsoilwatercontent. . . . . . . . . . . . . . . . . 56
4.3.4 Effectoftillageonaggregatestability. . . . . . . . . . . . . . . . . 56
4.3.5 Effectoftillageonsoildrybulkdensity . . . . . . . . . . . . . . . 56
4.3.6 Effectoftillageonpenetrationresistance . . . . . . . . . . . . . . 56
4.3.7 Effectoftillageonsoilorganicmattercontentandcarbonstocks . . 57
4.3.8 Effectoftillageoncropyield. . . . . . . . . . . . . . . . . . . . . 57
4.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.4.1 Soilphysicalfunctions. . . . . . . . . . . . . . . . . . . . . . . . 57
4.4.2 Soilstructuralparameters . . . . . . . . . . . . . . . . . . . . . . 61
4.4.3 Soilorganicmatterandcarbonstocks . . . . . . . . . . . . . . . . 62
4.4.4 Cropyield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.5 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5 Soilwaterandtemperaturedynamicsincontrastingtillagesystemsunder
conventionalandorganicfarming 65
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.2 MaterialsandMethods . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.2.1 Sitedescription . . . . . . . . . . . . . . . . . . . . . . . . . . . 69