1. Earth Observation for Food SecurityWeather & Climate Crop YieldsKees de Bie, NRSInroduction on Variability Sources andAgronomic Realities31 Jan. 2013, ITC-UT.Dynamics of 2 days! Dynamics of 1 year!Rainfall NDVI

2. Current use of NDVI imagery: Anomaly Mapping at 7-10 days intervalsSouth Sudan (WFP, 2010)WFP (GEOS-meeting):We need to combine itwith info/maps on:- Cropping system- Farming systems- Crop calendars,- Coping capacity- Vulnerability- Productivity, etc.FEWS, Giews (FAO), (global!!)Its pixel-based, andit does not consider what is where and when !If anomalous areas are detected: so what ?All concernsinfo as requiredfor properLand UsePlanning!This deals mainlywith weather relatedperformance variability 3. SPOT-VGT NDVIS-10 MVC-imagery: 1998-2011Greenness of Luzon during a yearClassifiedimage10-dayperiods(3 per month)Spatial-temporal stratification: Land Use Mapping (Luzon, Philippines)(de Bie, unpublished) 4. 120140160180200220Jan Apr Jul OctNDVI(DN-Value)ClassifiedimageLegend ofselected classesSpatial-temporal units derived must be linked to data!SPOT-VGT NDVIS-10 MVC-imagery: 1998-2011(de Bie, unpublished) 5. 250mresolutionAreas of interests are verylocal and fragmented(inland valleys, local-depressions)Includes signals fromother land cover typesFor instance: de-aggregate existing agric.statistics to prepare crop maps (de Bie, unpublished)Note: even inv.cloudyenvironments, this methodworks!! 6. (Nguyen Thi Thu Ha et al., 2012)or survey (describe and interview in the field) and characterize unitsLegend consists of more pages 7. Of units, past performance must be studied to support future projections(de Bie et al., 2011)Rice,Sevilla,SpainMen-causedchanges!Not related toimpacts ofclimatechange (yet). 8. By unit (area), the development potentials and risks must be mappeddifferent farmers indifferent regionsoperate atdifferent developmentlevels within aregion, always yieldvariability betweenfields remains.What happens to thisvariability when e.g. adrought, extremeevent, or a seriouspests/disease attackoccurs ?Paddy, Phrao, Thailandafter serious rice-blast(once every 10-years)Laborte and de Bie, 2012) Variability remains ! 9. By area, the yield increase trends, production requirements, and yield potentialscan be projected (till 2050)(Laborte and de Bie, 2012) 10. Besides growth definingfactors (= potential yield)actual yield is influenced by:growth limiting factorsyield reducing factorspast land modificationsYieldFeasibleProblemsManagementPlot-to-plot variabilityProblemsProblemsProblemsProblemsProblemsFarmers actions aim to removethrough managementthe limiting and reducing factors.Their coping-ability and ability toinvest in land (to modify fertility orinfra, etc.) is farmerand situation specific !!By unit, field-based studies on yield gaps leads to planning options De Bie (2000) 11. Besides growth definingfactors (= potential yield)actual yield is influenced by:growth limiting factorsyield reducing factorspast land modificationsTo modify choose Insert then Header and footer25/06/2013YieldFeasibleProblemsManagementPlot-to-plot variabilityProblemsProblemsProblemsProblemsProblemsFarmers actions aim to removethrough managementthe limiting and reducing factors.Their coping-ability and ability toinvest in land (to modify fertility orinfra, etc.) is farmerand situation specific !!This variabilityis region andyear specific.What causes variability in yields between plots ? (strictly biophysical) De Bie (2000) 12. 01000200030004000500060007000Yield(kg/ha)farmers fields research stationweedingsoil typevarietylodgingwater stressdiseasestimely plantingcropping systemPotential YieldYieldGapActual YieldAverage YieldGraphical presentationYield gap studies provide inputs for plannersWhat causes variability in yields between plots ? (strictly biophysical) 13. Yield gap studies translated as input for plannersRelevant land characteristics:The yield constraints and their relative importance:Advise to organizations: water shortage (41%) a location problem diseases incidence (22%; rice blast & brown leaf spot) late planting (18%) a labor availability problem lodging (10%) a variety problem poor soil condition (8%) a location problem Water-loss from paddies,defined by the soil infiltrationrate (= site specific) Water shortage, defined by thedistance from weirs (= mapunit specific) // can still beoptimized through LUP Plant breeders must concentrateon resistance to drought,diseases, and lodging. Extension services are bestconcerned with watermanagement, timely planting,and control of diseases.What causes variability in yields between plots ? (strictly biophysical) 14. Review Using hyper-temporal NDVI imagery, we can carry out improved land usemapping (combined with data mining or traditional survey methods) We must link hyper-temporal maps to: Crop calendars Management Perils (risks) Farming systems Coping capacities Vulnerabilities Productivities Yield gap facts, etc. We can use the maps to assess past performance and predict (with pastfacts) future trends and needs We can use derived facts and relationships, to feed land use planning But how to assess impacts of Climate Change??? (next lecture)To estimate impacts ofclimate change, werequire the use of cropgrowth models !! 15. THANK YOU