TROPICAL SOILS UNDER DIRECT SEEDING, MULCH-BASED CROPPING SYSTEMS Madagascar, December, 2007

CONTROLCONTROL OFOF SOILSOIL EROSIONEROSION ININ BRAZILBRAZIL BYBY THETHE NONO--TILLAGETILLAGE TECHNIQUE:TECHNIQUE: IMPORTANTIMPORTANT POINTSPOINTS TOTO BEBE CONSIDEREDCONSIDERED N.N. P.P. COGOCOGO;; J.J. E.E. Denardin;Denardin; I.I. Bertol;Bertol; F.F. L.L. F.F. Eltz;Eltz; L.L. B.B. dada S.S. VolkVolk

Brazilian Soil Science Federal University of Rio Society - SBCS Grande do Sul - UFRGS EQUATOR

BRAZIL . Antananarivo . CAPRICORN Brasília MADAGASCAR TROPIC . Porto Alegre (UFRGS)

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 RAINFALLRAINFALL DISTRIBUTIONDISTRIBUTION SubtropicalSubtropical regionregion ƒƒ ≅≅ 1,8001,800 mmmm yearyear-1 -1 220 ƒƒ ≅≅ 150150 mmmm monthmonth 200 180

160 140 120 100 80 Rainfall (mm) 60 40 20 0 JFMAMJJASOND Cogo; Denardin; Bertol; Eltz; Volk December, 2007 RAINFALLRAINFALL DISTRIBUTIONDISTRIBUTION TropicalTropical regionregion ƒƒ ≅≅ 1,4401,440 mmmm yearyear-1 -1 220 ƒƒ ≅≅ 120120 mmmm monthmonth 200 180

160 140 120 100 80 Rainfall (mm) 60 40 20 0 JFMAMJJASOND Cogo; Denardin; Bertol; Eltz; Volk December, 2007 RAINFALLRAINFALL EROSIVITYEROSIVITY ≅≅ 3,0003,000 toto 14,00014,000 MJMJ mmmm haha-1 hrhr-1 yryr-1 ƒƒ TROPICALTROPICAL REGIONREGION ConcentratedConcentrated inin SpringSpring andand SummerSummer ƒƒ SUBTROPICALSUBTROPICAL REGIONREGION RegularlyRegularly distributeddistributed throughoutthroughout thethe yearyear

HIGHHIGH RAINFALLRAINFALL--EROSIONEROSION POTENTIALPOTENTIAL

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 SOILSSOILS TYPETYPE ANDAND DISTRIBUTIONDISTRIBUTION

Latosol - Red Latosol - Yellow 38.7% Latosol - Brown Latosol - Red-Yellow Argisol 20.0% Neosol - sand quartz 14.6% Plinthosol 6.0% Cambisol 2.7% Nitosol 1.4% Others 16.6%

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 GENERALGENERAL CHARACTERISTICSCHARACTERISTICS Latosols,Latosols, Argisols,Argisols, andand NitosolsNitosols ƒƒ DeepDeep ƒƒ WellWell--draineddrained ƒƒ DistributedDistributed onon slightlyslightly rollingrolling toto rollingrolling landscapelandscape

NoNo limitationslimitations forfor mechanizationmechanization Cogo; Denardin; Bertol; Eltz; Volk December, 2007 GENERALGENERAL CHARACTERISTICSCHARACTERISTICS Plinthosols,Plinthosols, Neosols,Neosols, andand CambisolsCambisols ƒƒ ShallowShallow ƒƒ PoorlyPoorly--draineddrained ƒƒ PresencePresence ofof stonesstones ƒƒ HillyHilly landscapelandscape

RestrictionsRestrictions forfor mechanizationmechanization Cogo; Denardin; Bertol; Eltz; Volk December, 2007 SOILSOIL ORGANICORGANIC MATTERMATTER

SOILSOIL TYPETYPE gg 100100 gg-1 NeosolsNeosols -- sandsand quartzquartz << 22 LatosolsLatosols << 44 ArgisolsArgisols << 44 PlinthosolsPlinthosols << 44 NitosolsNitosols << 44 CambisolsCambisols >> 44

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 SOILSOIL MINERALOGICALMINERALOGICAL CHARACTERISTICSCHARACTERISTICS InIn generalgeneral ƒƒ ClayClay fractionfraction àà 11 :: 11 ÎÎ (( caolinitecaolinite )) àà oxidesoxides ÎÎ FeFe andand AlAl

LOWLOW CONTENTCONTENT OFOF HIGHHIGH SOILSOIL--AGGREGATEAGGREGATE WATERWATER––DISPERSEDDISPERSED CLAYCLAY STABILITYSTABILITY

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 SOILSOIL PHYSICALPHYSICAL CHARACTERISTICSCHARACTERISTICS InIn generalgeneral ƒƒ TotalTotal porosityporosity àà cancan exceedexceed 0.600.60 mm3 mm-3 àà HighHigh soilsoil--aggregateaggregate stabilitystability

ƒ HighHigh permeabilitypermeability toto water,water, air,air, andand rootsroots ƒ LowLow toto mediummedium susceptibilitysusceptibility toto waterwater erosionerosion Cogo; Denardin; Bertol; Eltz; Volk December, 2007 WATERWATER EROSIONEROSION SUSCEPTIBILITYSUSCEPTIBILITY SoilSoil erodibilityerodibility

SOILSOIL TYPETYPE ERODIBILITYERODIBILITY 1 LatosolsLatosols 0.0080.008 toto 0.0200.020 ArgisolsArgisols 0.0200.020 toto 0.0450.045 NitosolsNitosols 0.0270.027 toto 0.0320.032

1 Factor K = Mg ha h MJ-1 ha-1 mm-1

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 SOILSOIL CHEMICALCHEMICAL CHARACTERISTICSCHARACTERISTICS InIn generalgeneral ■ LowLow pHpH ƒƒ HighHigh aluminumaluminum ƒƒ LowLow availableavailable phosphorusphosphorus ƒƒ LowLow cationcation exchangeexchange capacitycapacity ƒƒ LowLow exchangeableexchangeable basesbases ƒƒ DystrophicDystrophic RestrictionsRestrictions forfor plantplant developmentdevelopment Cogo; Denardin; Bertol; Eltz; Volk December, 2007 -- 22nd HALFHALF OFOF 19601960’’S:S: SOILSOIL FERTILITYFERTILITY IMPROVEMENTIMPROVEMENT (soil(soil acidityacidity andand fertilityfertility correction)correction) ƒƒ increasedincreased cropcrop yieldyield ƒƒ ImprovedImproved profitabilityprofitability andand competitivenesscompetitiveness ƒƒ ImprovedImproved landland valuevalue

SOILSOIL ANALYSISANALYSIS LABORATORYLABORATORY NETWORKNETWORK àà importantimportant supportsupport forfor agriculturalagricultural frontierfrontier expansionexpansion Cogo; Denardin; Bertol; Eltz; Volk December, 2007 AGRICULTURALAGRICULTURAL FRONTIERFRONTIER EXPANSIONEXPANSION HISTORYHISTORY ƒƒ BeginningBeginning :: midmid 19601960’’ss àà StartingStarting fromfrom :: forestforest andand pasturepasture landslands ƒ Great changes: 1970 decade à Replacement of forest and pasture areas by monoculture (wheat, soybean, maize, rice)

3 Conventional tillage 3 Limestone and fertilizers Cogo; Denardin; Bertol; Eltz; Volk December, 2007 AGRICULTURALAGRICULTURAL FRONTIERFRONTIER EXPANSIONEXPANSION SoilSoil managementmanagement practicespractices ƒ Intensive soil mobilization ƒ Intensive use of lime and fertilizers ƒ Wheat/soybean or fallow/soybean ƒ Biomass production lower than SOM decomposition CONSEQUENCES à Improvement of soil chemical characteristics àDegradation of soil structure

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 DEGRADATION OF SOIL STRUCTURE

Minerals Minerals 35 % 62 % SOM 3 % SOM 2 % Air Air Water 30 % 5 % 32 % Water 31 % LATOSOL UNDER LATOSOL UNDER NATURAL CONDITION CONVENTIONAL TILLAGE

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 DEGRADATIONDEGRADATION OFOF SOILSOIL STRUCTURESTRUCTURE (Latosol,(Latosol, conventionalconventional tillage)tillage)

33 yearsyears 77 yearsyears SoilSoil SoilSoil AggregateAggregate SoilSoil AggregateAggregate layerlayer densitydensity stabilitystability densitydensity stabilitystability (cm) (g cm-3) (%) (g cm-3) (%) 00 -- 66 ## ## ## ## 66 --1414 1.201.20 7878 1.431.43 4848 1414 -- 2323 1.201.20 7979 1.401.40 5858 2323 -- 3030 1.181.18 7878 1.251.25 5656 # No aggregates > 4.76 mm.

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 AGRICULTURALAGRICULTURAL FRONTIERFRONTIER EXPANSIONEXPANSION SoilSoil conservationconservation practicespractices ƒ Contouring ƒ Terracing à narrow and medium base (later broad-base), absorption type in Latosols and drainage type in Argisols

THEY WERE SYNONYMS OF SOIL CONSERVATION à Insufficient to control water erosion

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONSEQUENCES OF POOR SOIL MANAGEMENT PRACTICES

SERIOUS EROSION PROBLEMS

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 POORPOOR SOILSOIL MANAGEMENTMANAGEMENT ANDAND EROSIONEROSION

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 POORPOOR SOILSOIL MANAGEMENTMANAGEMENT ANDAND EROSIONEROSION

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 POORPOOR SOILSOIL MANAGEMENT,MANAGEMENT, EROSION,EROSION, ANDAND WATERWATER POLLUTIONPOLLUTION

WHAT TO DO?

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 EROSIONEROSION RESEARCHRESEARCH

-- TheThe beginning:beginning: 19401940 decadedecade

-- NationwideNationwide efforts:efforts: 19701970 decadedecade

-- Type:Type: fieldfield runoffrunoff--plots,plots, underunder naturalnatural andand simulatedsimulated rainfallrainfall

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 Cogo; Denardin; Bertol; Eltz; Volk December, 2007 Cogo; Denardin; Bertol; Eltz; Volk December, 2007 ROTATING-BOOM RAINFALL SIMULATOR (SWANSON’S TYPE)

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 EROSIONEROSION RESEARCHRESEARCH RESULTSRESULTS SOILSOIL LOSSESLOSSES BYBY EROSIONEROSION ININ DISTINCTDISTINCT SITUATIONSSITUATIONS

Soil Crop Exp. time CBS CIS MT NT yearyear ------MgMg haha-1 yryr-1 ------Latosol w/s 6 10.9 3.6 - 1.5 Latosol w/s 4 - 3.2 - 1.1 Latosol f/s 6 9.0 6.0 - 5.0 Argisol w/s 9 - 13.1 3.2 0.5 Argisol w/s 4 - 5.3 - 1.0 Argisol w/s 4 51.5 39.5 - 2.2 Nitosol w/s 11 - 34.0 11.3 8.8 Nitosol w/s 4 - 6.0 - 0.2 CBS: conventional tillage, burned stubble; CIS: conventional tillage, incorporated stubble; MT: minimum tillage; NT: no-till W/S: wheat/soybean; f/S: fallow/soybean Cogo; Denardin; Bertol; Eltz; Volk December, 2007 EROSIONEROSION RESEARCHRESEARCH RESULTSRESULTS SOILSOIL LOSSESLOSSES BYBY EROSIONEROSION ININ DISTINCTDISTINCT SITUATIONSSITUATIONS

REGION SOIL PERIOD BS CBS CIS NT % ------Mg ha-1 yr-1 ------Subtropical Latosol Winter 67.5 5.5 ---1.7 0.7 51 Summer 65.1 5.4 1.9 0.8 49 Total 132.6 10.9 3.6 1.5 100 Tropical Latosol Winter 4.0 0 0 0 5 Summer 49.0 9.0 6.0 5.0 95 Total 53.0 9.0 6.0 5.0 100 BS: bare soil; CBS: conventional tillage, burned stubble; CIS: conventional tillage, incorporated stubble; NT: no-till

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONSERVATIONCONSERVATION MANAGEMENTMANAGEMENT PRACTICESPRACTICES NoNo--tilltill systemsystem ƒ Concept à Complex technology based on species diversification - intercropping or crop rotation -, minimization or suppression of crop- season gap, permanent soil coverage, and mobilization of the soil only in the seed- row.

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONSERVATIONCONSERVATION MANAGEMENTMANAGEMENT PRACTICESPRACTICES AdoptionAdoption ofof nono--tilltill inin BrazilBrazil 24.000.000 Period Period Period 20.000.000 1974-1979 1980-1992 1993-2006 11.900 79.000 1.710.000 ha/year ha/year ha/year 16.000.000 till system till till system till - - 12.000.000 ( ha ) ( ha ( ha ) ( ha

8.000.000 Area under no under Area Area under no under Area 4.000.000

0 1974 1978 1982 1986 1990 1994 1998 2002 2006 YEAR

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM ININ BRAZILBRAZIL ReasonsReasons forfor acceleratedaccelerated adoptionadoption ƒƒ EffectiveEffective wayway forfor controllingcontrolling waterwater erosionerosion ƒƒ ReductionReduction ofof time,time, labor,labor, andand costscosts associatedassociated withwith tillagetillage andand seedingseeding operationsoperations ƒƒ PossibilityPossibility ofof implementingimplementing agricultureagriculture-- livestocklivestock combinationcombination

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONSERVATIONCONSERVATION MANAGEMENTMANAGEMENT PRACTICESPRACTICES NoNo--tilltill systemsystem evolutionevolution ƒ Different phases, based on temporal and spatial arrangement of species 1st h wheat/soybean

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM ININ BRAZILBRAZIL (TROPICAL(TROPICAL PORTION)PORTION) 11st PHASEPHASE OO NN DD JJ FF MM AA MM JJ JJ AA SS OO

SoybeanSoybean WheatWheat GapGap

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONSERVATIONCONSERVATION MANAGEMENTMANAGEMENT PRACTICESPRACTICES NoNo--tilltill systemsystem evolutionevolution ƒ Different phases, based on temporal and spatial arrangement of species 1st h wheat/soybean 2nd h black oats or radish/soybean

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM ININ BRAZILBRAZIL (TROPICAL(TROPICAL REGION)REGION) 22nd PHASEPHASE OO NN DD JJ FF MM AA MM JJ JJ AA SS OO

SoybeanSoybean BlackBlack oatsoats GapGap OROR SoybeanSoybean RadishRadish GapGap

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONSERVATIONCONSERVATION MANAGEMENTMANAGEMENT PRACTICESPRACTICES NoNo--tilltill systemsystem evolutionevolution ƒ Different phases, based on temporal and spatial arrangement of species 1st h wheat/soybean 2nd h black oats or radish/soybean 3th h soybean/millet

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM ININ BRAZILBRAZIL (TROPICAL(TROPICAL REGION)REGION) 33th PHASEPHASE OO NN DD JJ FF MM AA MM JJ JJ AA SS OO

SoybeanSoybean MilletMillet MilletMillet

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONSERVATIONCONSERVATION MANAGEMENTMANAGEMENT PRACTICESPRACTICES NoNo--tilltill systemsystem evolutionevolution ƒ Different phases, based on temporal and spatial arrangement of species 1st h wheat/soybean 2nd h black oats or radish/soybean 3th h soybean/millet Presently h soybean/maize/brachiaria- livestock combination

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM ATAT PRESENTPRESENT ININ BRAZILBRAZIL (TROPICAL(TROPICAL REGION)REGION)

OO NN DD JJ FF MM AA MM JJ JJ AA SS OO

SoybeanSoybean MaizeMaize BrachiariaBrachiaria && LivestockLivestock

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM ATAT PRESENTPRESENT ININ BRAZILBRAZIL -- minimizationminimization oror suppressionsuppression ofof cropcrop--seasonseason gapgap (harvest-plant process) Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM ATAT PRESENTPRESENT ININ BRAZILBRAZIL -- minimizationminimization oror suppressionsuppression ofof cropcrop--seasonseason gapgap

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--tILLtILL SYSTEMSYSTEM ATAT PRESENTPRESENT ININ BRAZILBRAZIL -- minimizationminimization oror suppressionsuppression ofof cropcrop--seasonseason gapgap

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 NONO--TILLTILL SYSTEMSYSTEM AT PRESENT IN BRAZIL -- minimization or suppression of cropcrop--seasonseason gapgap

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 PROBLEMSPROBLEMS ASSOCIATEDASSOCIATED WITHWITH THETHE NONO--TILLTILL THECNIQUETHECNIQUE ININ BRAZILBRAZIL (SUBTROPICAL(SUBTROPICAL REGION)REGION) TheThe strong,strong, generalgeneral impactimpact ofof nono--tilltill ƒ leadsleads toto anan erroneouserroneous thoughtthought Î induced by the idea that it would be enough, as isolated practice, to control all the erosion problems

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 MISTAKENMISTAKEN INTERPRETATIONINTERPRETATION OFOF NONO--TILLTILL ConsequencesConsequences ƒƒ TerracesTerraces werewere removedremoved ƒƒ ContouringContouring waswas abandonedabandoned ƒƒ Excessive grazing in the agricultureagriculture--livestocklivestock combination ƒƒ Cropping systems restricted to soybean oror maize/voluntarymaize/voluntary blackblack oatoat oror ryegrassryegrass

à Soil degradation - surface compaction à Low soil coverage - mulch failure Cogo; Denardin; Bertol; Eltz; Volk December, 2007 MISTAKENMISTAKEN INTERPRETATIONINTERPRETATION OFOF NONO--TILLTILL EffectsEffects

TerracesTerraces removalremoval

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 MISTAKENMISTAKEN INTERPRETATIONINTERPRETATION OFOF NONO--TILLTILL Effects

ContouringContouring abandonementabandonement

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 MISTAKENMISTAKEN INTERPRETATIONINTERPRETATION OFOF NONO--TILLTILL Effects

Countouring abandonement

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 BREAKDOWNBREAKDOWN ININ PRACTICEPRACTICE EFFECTIVENESSEFFECTIVENESS (Wischmeier,(Wischmeier, 1973)1973)

- “ There are critical slope-length limits beyond which

the effectiveness of conservation tillage practices

diminishes so that C values derived from the regular

soil-loss ratio procedure are no longer applicable ”

- Also called “mulch failure”

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 Cogo; Denardin; Bertol; Eltz; Volk December, 2007 Cogo; Denardin; Bertol; Eltz; Volk December, 2007 Cogo; Denardin; Bertol; Eltz; Volk December, 2007 EROSIONEROSION UNDERUNDER CONSERVATIONCONSERVATION TILLAGETILLAGE

CRITICALCRITICAL SLOPESLOPE--LENGTHLENGTH LIMITSLIMITS ININ CONSERVATIONCONSERVATION TILLAGETILLAGE Crop residue Critical Tillage length Type Dosage Condition (Mg ha-1) (m) No-tillage maize 12 fresh 328 - 483 No-tillage wheat 4 fresh 106 - 143 No-tillage soybean 5 fresh 94 - 108 Reduced tillage maize 12 fresh 147 - 209 No-tillage maize 5 semi-dec. 87 - 174 No-tillage soybean 4 semi-dec. 29 - 58

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 MISTAKENMISTAKEN INTERPRETATIONINTERPRETATION OFOF NONO--TILLTILL EffectsEffects (mulch(mulch failure)failure)

Pontão - May, 2007 Pontão - May, 2007

Pontão - May , 2007 Pontão - May , 2007 Cogo; Denardin; Bertol; Eltz; Volk December, 2007 MISTAKENMISTAKEN INTERPRETATIONINTERPRETATION OFOF NONO--TILLTILL

SOILSOIL ANDAND WATERWATER LOSSESLOSSES ININ DISTINCTDISTINCT TILLAGETILLAGE METHODSMETHODS

TillageTillage methodmethod SoilSoil lossloss WaterWater lossloss - - Mg ha-1 - - - - % rainfall - - Bare,Bare, conv.conv.--tilledtilled soilsoil 16.40 45.5 ConventionalConventional tillagetillage 1.94 11.8 ReducedReduced tillagetillage 0.13 4.6 NoNo--tillagetillage 0.12 9.8

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 MISTAKENMISTAKEN INTERPRETATIONINTERPRETATION OFOF NONO--TILLTILL NUTRIENTNUTRIENT LOSSESLOSSES ININ SURFACESURFACE--RUNOFFRUNOFF

10

) P - total -1 8 N - total 6 4 2 P and N ( kgP and N ha ( 0 RT, check NT, check RT, min. NT, min.

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 CONCLUSIONCONCLUSION ƒ The no-till system, built on: à agriculture or agriculture-livestock combination with crop rotation à minimization or suppression of crop-season gap à use of mechanical and vegetative erosion control practices à soil acidity and soil fertility correction à precise use of inputs

CERTAINLY CAN BE USED AS AN EFFICIENT TOLL FOR A SUSTAINABLE AGRICULTURE IN TROPICAL AND SUBTROPICAL REGIONS

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 FINALFINAL CONSIDERATIONCONSIDERATION ƒƒ UsageUsage ofof nono-- tilltill asas aa tooltool forfor agricultureagriculture developmentdevelopment andand conservationconservation inin thethe tropicstropics dependsdepends onon bothboth thethe QUALITYQUALITY andand thethe QUANTITYQUANTITY ofof biomassbiomass producedproduced byby crops.crops.

Cogo; Denardin; Bertol; Eltz; Volk December, 2007 Neroli Pedro Cogo [email protected]

Soils Department Faculty of Agronomy Federal University of Rio Grande do Sul - UFRGS - THANK YOU! Cogo; Denardin; Bertol; Eltz; Volk December, 2007