soil health and how - purdue university college of … health and how to measure it lori hoagland...
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Soil health and howSoilhealthandhowto measure ittomeasureit
LoriHoagland
AssistantProfessor
DepartmentofHorticulture&L d A hiLandscapeArchitecture
PurdueUniversity
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Outline
Wh t i il h lth d h h ldWhatissoilhealthandwhyshouldwecareaboutit?
Whatconstituteshealthysoil?
Howcanyoubuildsoilhealth?
H il h lth?Howcanyoumeasuresoilhealth?
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Whyshouldyoucarey yaboutsoilhealth?
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Analogy
Youregoingonatrip whichtiresdoyouwant?
Leakytires FullyinflatedtiresOR
EricBrennan USDAARS
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Analogy
P il= PoorsoilqualityqualityLeakytiresy
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Whatissoilhealth?
Definition: The capacity of a living soil to:Definition:Thecapacityofalivingsoilto: functionwithinnaturalormanaged
b d iecosystemboundaries sustainplantandanimalproductivityp p ymaintainorenhancewaterandair
litquality promoteplantandanimalhealthp p
(Doranetal.,1996,1998)
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Whycareaboutsoilhealth?
Alleviate soil compactionAlleviatesoilcompaction
Increasewaterinfiltrationandwaterholdingcapacity
R d i i i d i hReduceirrigationcostsandimprovethepotentialforyoursoiltowithstanddrought
R d i d k il i lReduceerosionandkeepyoursoilinplace
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Consequencesofpoorsoilhealth
A single inch ofAsingleinchoftopsoilcantake500
yearstoformnaturally
Erosion in the Palouse
SurfacerunofffromafarmfieldinIowaduringarainstorm
naturally
Columbia River Basin from space Fall 2009
g
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Whycareaboutsoilhealth?
Reduce incidence of pest outbreaks andReduceincidenceofpestoutbreaksandlowerpesticidecosts
Increasenutrientholdingcapacityofthe
soil reduce nutrient loss and lowersoil,reducenutrientlossandlower
fertilizercosts
Improvecropproductivityandqualityofyour produceyourproduce
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Whatconstituteshealthysoil?y
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ComponentsofsoilhealthChemical wellunderstoodandapplied
Physical fairlywellunderstood but not
Biological theleastunderstood andunderstood,butnot
oftenappliedMoebius, 2004
understoodandapplied
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Relevanceofchemicalsoilhealth
pH measureofacidityoralkalinityofthesoil
impacts:
nutrientavailabilityy
availabilityoftoxicmetals
activities of microorganisms activitiesofmicroorganisms
thatfacilitatenutrient
li d d dicyclingandreducedisease
risk
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Relevanceofchemicalsoilhealth
Salinity saltcontentofthesoili i i i f ili d inirrigationwater,fertilizers,compostsandmanure
accumulationcandegradesoilstructureandrestrict
vegetablegrowth
Cation exchangecapacity quantityofcations inthesoil cation isapositivly chargedion(ie.Ca2+,Mg2+, NH4+,
Zn2+,Cu2+,Mn2+)
dependsonamountofclayandorganicmatterinthesoil
impactsthesoilsnutrientholdingcapacity
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Relevanceofphysicalsoilhealth
Soiltexture proportionofsand,siltandclayparticles in the soilparticlesinthesoil
functionofsoilsparent
material
virtually unchangeablevirtuallyunchangeable
exceptthrougherosion
importantforsoiltest
interpretation
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Relevanceofphysicalsoilhealth
Soilstructure(ortilth) arrangementofsoilparticlesinto aggregatesintoaggregates canchangerapidlyinresponsetomanagement
T th t t d t tTogethertextureandstructure
impact:W t d t i t h ldi itWaterandnutrientholdingcapacity
Waterinfiltration
Aeration Aeration
Seedgerminationandrootproliferation
Biologicalactivity
Moebius, 2004
g y
Erosionpotential
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RelevanceofbiologicalsoilhealthItsAlive!Megafauna mice,ants,
earthworms spiders etcearthworms,spiders,etc.
initiateorganicmatter
decompositiondecomposition
aeratethesoil
f dMesafauna nematodes,
mites,springtails
regulatemicrobial
populations
Microfauna bacteria&fungi
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Regulatenutrientcycling
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Improveplanthealth
Rhizosphere zoneofgreatest
RootssupportmicrobesMicrobesaidplants
microbialactivityRhizobia
Releasesignals&
Fixnitrogen
Solubilizephosphorous
ppp
gnutrients
Enhancerootgrowth Provideprotection
Suppressplantpathogens
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Morebenefitsofsoilbiologicalhealth
Buildsoilaggregates secretebiologicalglue
Filter and detoxify chemicalsFilteranddetoxifychemicals
Make that sweet smellMakethatsweetsmell Streptomyces&geosmin
Guides camels Guidescamels
Glomalin productionbymycorrhiza
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Howcanyoubuildyhealthysoil?y
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Addorganicmatter
Beneficialimpactsonsoilproperties:
Chemical higherCEC,pHbuffer,tiesupmetals,interactswithxenobiotics
Physical stabilizessoilstructure,improveswaterholdingcapacity,reducedcompaction,darkcolorhelpswarmsoilp y, p , p
Biological suppliesenergyandbodybuildingconstituentsf il i d i k f t i t ( ilforsoilorganisms,sourceandsinkfornutrients(soilfertilitybankaccount),ecosystemresilience
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(H.Atthowe)
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Applybiologicalamendments
Eric Zakarison demonstrates his solorpowered tractor
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Plantcovercrops
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Reducetillage
Notillvegetabletransplanter
http://www.separcd.org/notill_vegetables.htm
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Restoringorganicmatter&soilhealth
(BradyandWeil,2002)
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Restoringorganicmatter&soilhealth
S il h lth Silt l Silt L Cl L Cl L
ImpactoftillageonsoilphysicalhealthSoil health indicator
Silt loamPlow till
Silt LoamNo - till
Clay LoamPlow till
Clay LoamNo till
Bulk density Not Not 1.21 1.03y(g/cm3) significant significantPores > 30 microns (%)
13 17 12 16
Pores < 30 microns (%)
Not significant
Not significant
29 24
Available water 12 16 Not significant Not significantcapacity (%)
Water stable aggregates
20 41 30 68aggregates 0.25-0.2 mm (%)
(Idowu etal.,2006)
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Restoringorganicmatterandsoilhealth
Impactoforchardfloormanagementonsoilhealth
compostapplicationcoupledwithhightillagedoesnot
positivelyimpactsoilhealthcharacteristics
covercropsresultindramaticimprovementinsoilphysical,
chemicalandbiologicalproperties
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RestoringorganicmatterandsoilhealthRestoringorganicmatter&soilhealth
ImpactofwheatcultivationonFluorescentPseudomonans
oil
Managingsoilbornepathogensinapplewithwheatcultivation
60
80
100
eudo
mon
asg
1so
b
a
ab
a a
0
20
40
Control Pasteurized Wheatgrass Modern Wheat
Organic Wheat
Perennial Wheatof
Fluorescentps bc
c
Wheat Wheat Wheat
60
Impactofwheatcultivationonsoilbornepathogens
#o
sg
1 soil
a
2030405060
borne
patho
gens
bb
ccc
010
Control Pasteurized Wheatgrass Modern Wheat
Organic Wheat
Perennial Wheat
#ofsoil
(Hoaglandetal.,2010)
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Canyouaddtoomuchorganicmatter?
Material C:NMicrobialTissues 612:1
InsomecasesyesSoilHumus 1012:1AnimalManure 1325:1LegumeResidues/GreenManures 1325:1Compost 25 30:1
Nutrientimmobilization
WatchthesaltCompost 2530:1CerealResidues/Straw 6080:1ForestRefuse 150500:1
Carefulwithnewly
incorporatedfreshp
residues
Requires careful 50006000
il
Tukey
PAR
ImpactofBrassicaseedmeal incorporationonPythium
Requirescareful
management1000
2000
3000
4000
cfu
pyth
/ g s
oi IRRECHULTHETATT
0Cnt Past. Bj Sa Bn Gm
ATT
Control Pasteurized
(Hoaglandetal.,2008)
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Howcanyoumeasureysoilhealth?
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Standardfertilitytestatacommerciallab
Recommended every 35 yearsRecommendedevery3 5years
Generallycost$1020
Typicallyincludes:pH,availablephosphorous,nitrogen,potassium,calcium,magnesiumandorganicmatter
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Collectingthesoilsample
Sampleatthesametimeeachyeartoachievemoreaccurate trendsaccuratetrends
Tools:samplingtubeorspade,buckets,plasticbags
Collectrepresentativesample
Soiltype,managementpractices,crop
growth&yield
Avoidirregularareas
2030coresper1020acrefield
Collectsamplestoadepthof approximately8
Mixandairdry
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CornellSoilHealthLab
Basictest($40) Comprehensive($65) Standardsoilfertilitytest(pH,OM,P,K,Ca,Mg,Al,Fe,Zn,Mn)
P ti l i di t ib ti
Basictest
Potentiallymineralizable
i ( ) Particlesizedistribution
Wetaggregatestability
Available water capacity
nitrogen(PMN)
RoothealthbioassayAvailablewatercapacity
Surfacehardness
Activecarbon
*Samplesshouldbetakeninthespringpriortotillage
http://soilhealth.cals.cornell.edu/extension/test.htm
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SoilFoodWeb
Soilfoodweb
http://oregonfoodweb.com/
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Measuringsoilhealthonthefarm
NRCSSoilQualityTestKit Electricalconductivity&pH
Soilnitrate
W t i filt ti & t litWaterinfiltration&waterquality
Bulkdensity
Aggregate stabilityAggregatestability
Slaketest
Soilrespirationp
Earthworms
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Measuringsoilhealthonthefarm
Soilqualityscorecards subjectivetestsbasedonfeel,siteandsmell
Mayincludecharacteristicssuchas: Earthworms
Organicmattercolor
Waterholdingcapacity
Drainage/infiltration
Organicmatterroots/residues
Subsurfacecompaction
S il il h/f i bili / ll
Cropcondition
pH
N t i t h ldi it Soiltilth/friability/mellowness
Erosion
Nutrientholdingcapacity
TalktolocalNRCSoffice
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Interpretingresults
Dependson:p
soiltype
crops grown cropsgrown
farmsizeandmanagement
Usetoevaluatechangesinpracticesovertimep
Practiceonfarmexperimentation
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ResourcesBuildingSoilsforBetterCrops Fred Magdoff and Harold van EsFredMagdoff andHaroldvanEs
SustainableAgricultureNetwork
http://www.sare.org/publications/soils.htm
SustainableSoilManagement SoilSystemGuide ATTRAATTRA
http://attra.ncat.org
Natural Resource Conservation ServiceNaturalResourceConservationService
PurdueExtensionEducators
LoriHoaglandlhoaglan@purdue.edu
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