Kimble - Plant Nutrition Group

Kimble - Plant Nutrition Group

Contributors to Presentation• Carlos C. Ceri, Brazil• Carlos E.P. Ceri, Brazil• Brent E. Clothier, New Zealand• H.H. Janzen, Canada• Charles W. Rice, USA• Pedro Sanchez, USA

Why the Interest in Soil Carbon?• Terrestrial systems can help mitigate increases ofatmospheric CO 2 by sequestering C into soils andvegetation.• Soil C is a large pool and small changes can have asignificant impact.• Globally, SOC pools are estimated at 1100 to 1600 Pg morethat 2 times that in vegetation (560 Pg), or in theatmosphere (750 Pg)• It is estimated that soil has the potential to offset 30%of the annual CO 2 emissions– The economic potential is ~30-50% of that value

Water Benefits from Soil C Sequestration5 cm rain on no-till

5 cm rain conventional till

Soil StructureConventional tillageNo-till

Treatment Runoff Sediment Nitrogen PhosphorusCu.Ft/Ac lb/ac lb/ac lb/acPlowed +fert 6506 3176.3 9.17 3.65No-till + Litter 1547 30.5 0.54 0.38No-till 2014 18.5 0.49 0.27No-till+ Fert 1537 5.4 0.47 0.26subsoilNo-till +fert 1373 16.0 0.46 0.25--------------------------------%----------------------------------AverageReduction 74.9 98.2 94.7 92.0By no-till

Hog Manure Injection

Managing Soils for C!• Increased Plant productivity• Enhanced Quality of:– Soil– Water– Air• Reduce soil erosion• Reduce energy inputs into the soil• Improved soil resources

Idaho about 40 Cm Rain/year350300250200150100Conventional TillNo-Till500Acres X100Tractorhours X10BarleyBu/AcWheatBu/Ac

GaseousEmissionsSoilBiodiversityMicrobialActivitySoilOrganicCarbonSoilStructureEnvironmentalServicesWaterErosion&AvailabilityNutrientCyclingSustainabilityPlant Growth

Need to translate scienceto policy makersScientists mostly talk toscientistsPolicy makers to policymakersand never shall they MEET!

Steps in communicationscience to policy makers!• Identify the end users & stake holders.• Determine what information is neededby users.• Tailor the information derived fromscientific results for the end users needs.• The bottom line is to help policy makersmake good decisions based on SCIENCE.

New Zealand• Intensification of agriculture isleading to a decline in soil C, butwe've not yet got a good handle onit (how much, and how it variesdown the profile), but this has ourpolicy people a bit worried from asoil health perspective.• Policy people want Indicators forSOIL QUALITY

Protecting Existing CarbonStocks• We need to keep or increase existingcarbon stocks, and this needs to beaddressed a a major policy option!• Incentives to change farming practices?• Reduce deforestation?• At a meeting in Brazil a few years agothe point was made that there is enoughland cleared if it was managed correctly!YET CLEARNG STILL GOES ON WHY?

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas EmissionsImportance of SOC at global scalePgAtmosphere 730+EmissionsVegetation 470-655Soil (0-30cm) ~700Soil(1m) 1500-2000Values in Gt C (1Gt = 10 9 t = 1 Pg)

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas EmissionsImportance of LULUCF to the radiative forcingRadiative forcings* by main sectorAgriculture20%IndustriescementAnd Fuel66%Land Use Change14%IPCC-SAR, 1996* Change in the energetic balance of the Earth

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas EmissionsImportance of LULUCF to the radiative forcing1.4 ± 0.20.7 ± 0.2CO 2CH 4N 2OIndustriescementAnd FuelRadiative forcings* by main sectorW.m -20.15 ± 0.0566%AgricultureAgriculture20%20%CO 2 5%CH 4 50%N 2 O 70%Land Use ChangeLand Use Change14%CO 2 17%CH 4 5%N 2 O 10%IPCC-SAR, 1996* Change in the energetic balance of the Earth

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas EmissionsRates of land use change is greatestin the tropicsFeed 70% of the population(Lal and Sanchez 1992)Increasing demand for land will bemet by converting forest andpasture (C release)~ 26% of global SOC stocks are inthe tropics (Batjes 1996)Relatively little information on soilsand how they react to land usechangeThe Tropics

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas EmissionsCarbon sequestration and international effortKyotoProtocolWe need more scientific knowledge

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas EmissionsGlobal distribution of soil organic carbon: native condition?Known knowsGlobal soil organic carbon ~ 1500 Pg0-100 cmWRI, 2000 (FAO, 1995 & Batjes, 1996)

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas Emissions?Problems of scaleKnown knowsPlotScaleRegional andNationalProblems• Many studies• Site specific• Limited value• Allows consideration ofvarying land use policy• Relevant to resourcemanagementGlobal• Informative• Limited effect on policyat ground level

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas Emissions?Known knows….most known isKnown knowsSoil organic matteris much more thana potential sink forstoring excess CO 2biologically,it is most usefulwhen it decays(Janzen 2006)EmissionsSequestration

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas Emissions?Known knowswin-win scenarioCO 2Combating landdegradation+3,2 ± 0,1 yr -1 Fossil fuelcombustionPreservingbiodiversityImprovingsoil qualityIncreasingsoil productivity

Soil Organic Carbon Stocks/Sequestrationand Greenhouse Gas EmissionscKnowledge of SOC stocks and changes is needed todevise plans for:• The sustainable management ofecosystems•The mitigation of GHG emissions•The likely impacts of climate changeon soils/ecosystems in the future

Soil Carbon Science Needs– Scaling processes for accounting of soilcarbon and GHG emissions.• Demonstration projects– Measurement/monitoring soil C changeand GHG emissions– Verification of accounting systems andaccounts of soil C change and GHGemissions– Establishing common databases for soilC and trace gases in relation to land useand management practices

Needs for Policy Makers• Relevant, easy to understandinformation for policy makers on soiland its relation to people– Global, national and local assessments forsoil C sequestration potential– Management options– Economics: both costs and benefits toproducer– Ancillary benefits to Society• Food security• Energy security• Sustainability• Rural Economy

Thank you

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