Hybrid PRZM“Filling in the gaps” in field sampling data usingrealistic simulation modelingPaul Miller Chris Harbourt WilliamNorthcottPaul Miller,Chris Harbourt,WilliamNorthcott,Paul Hendley and Jessie J. PrengerWaterborne Environmental, IncandSyngenta Crop Protection.1EMPM Meeting, March 20thWaterborne Environmental, Inc.andSyngenta Crop Protection1Why is this needed?Concern exists that monitoring programs may be missing peaksTension opposite cost of ultra-frequent monitoringBias factors are promising for extrapolating moderate frequencymonitoring data to conservatively estimate higher frequency datae.g. estimating 4 day rolling averages from 7-day monitoring dataBUT challenge is how to use bias factorsMultiply entire period, assume “missed peaks” every week......Instead, what about using more realistic ways of predictingpossible peaks between gaps in measured concentrationsE.g. Includinglocalinformation on weather, watershed cropping,and agronomy to identify when peaks might have occurredDevelopingmore accurate representation ofpeak occurrence,g p p ,duration and magnitude and thusRealistically reduce uncertainty of evaluationsWaterborne Environmental, IncandSyngenta Crop Protection.2EMPM Meeting, March 20thKey Enabler: Crop District Modeling/Data SystemAdditional DataPlanting DateCrop MaturitySoils DataCropland Data LayerWeather VariablesNEXRAD RainTemperatureSolarDatabaseData on DemandHistorical/Current(Rain Temp GDDModeling ApplicationsNear Real-time TrackingC Yi ld M d lDatabaseSystem(Rain,Temp,GDD,Moisture)Summarized byDistrictCropYield ModelSoil Moisture ModelCrop Condition / StressOutputTabularGraphicalWaterborne Environmental, IncandSyngenta Crop Protection.3EMPM Meeting, March 20thKey Enabler: LOCAL NEXRAD rainfall data for any watershedf i t tof interestWaterborne Environmental, IncandSyngenta Crop Protection.4EMPM Meeting, March 20thPRZM Hybrid uses tools we understand!!Pesticide Root Zone Model (PRZM) version 3.12.2 used tosimulate edge-of-field runoff from representative agriculturalsoils in each subwatershedsoils in each subwatershed.Site specific input parameters include Corn and Sorghum on specificSSURGO soilslocally measured weather data, application timing based onl d k bili l i hlandworkabilityalgorithm,and a watershed percent treated area (PTA) based on CDLland-use data and grower survey data (local but not specific)PRZM Modeling integrates variables of interestPRZM outputSite-year specificCroppingNEXRAD local rainfallAllows comparison to and integration with monitoringWaterborne Environmental, IncandSyngenta Crop Protection.5EMPM Meeting, March 20thPRZM-Hybrid is Site & Local Event Specific*Uses PRZM codeAtrazine Efate dataRegional dataCrop reporting districtbased atrazineapplication rateWatershed & year specificlocaldataSSURGO soilsNEXRAD rainfall% Crop (NASS CDL(NLCD))OutputUses directly availabledata - No model specificcalibrationConservative edge-offield concentrationsUncertainties definedWaterborne Environmental, IncandSyngenta Crop Protection.6EMPM Meeting, March 20th*Atrazine: Development of the PRZM-Hybrid Watershed Exposure Modeling SystemMethodology Report – Miller et al. April 2011Key Enabler: Algorithm to Simulate Farmer Behavior andAgronomic Timing Based on LOCAL ConditionsNew application algorithm accounts for land “workability” anddistribution across time and addressesLOCALf il t i f ll f h th l d bresponseofsoilstorainfall forwhetherlandcanbeworkedWariness of some farmers not to plant too earlyNeed for seed bed to be prepared in first workable days for tilledfieldsEquipment capacity constraint on applying very large fraction ofthe watershed in a dayPossibilities for post emergent treatmentsWaterborne Environmental, IncandSyngenta Crop Protection.7EMPM Meeting, March 20thKey Enabler: Algorithm to Simulate Farmer Behavior andAgronomic Timing Based on LOCAL ConditionsWorkability ApproachDetermine first planting date from 14 day moving average of airtemperature, when >55 degrees (F) and soil moisture is≤0.85 and dateis April 1st or later then planting is “Possible”Window for potential applications starts 7 days prior to 630 GDDSoil moisture accounting uses water balance (not based on PRZMestimates) starting March 1stLand Workability defined as a ratio of 0.9 or less (soil moisture /soilmoisture at field capacity)Applies equal amounts on all workable days in the application windowWaterborne Environmental, IncandSyngenta Crop Protection.8EMPM Meeting, March 20thNot accounting for local variation gives “OK” predictionsIn earlier method, application was distributed evenly basedon growing degree days. This results in under and overpredictions through the seasonGreen bars reflect afraction of the totalseasonal chemical loadbeing applied in an evenpattern across a GDDdefined windowdefinedwindowWaterborne Environmental, IncandSyngenta Crop Protection.9EMPM Meeting, March 20thUsing LOCAL conditions to help predict farmer behavior/agronomy improves things!With chemical applications not being made when weatherwould not allow field operation, effect is to have morerealistic estimates of mass available for runoff when the“next “ rainfall happensGreen bars reflect a fraction of thetotal seasonal chemical load beingapplied on each day application isjudged feasiblejudgedfeasibleWaterborne Environmental, IncandSyngenta Crop Protection.10EMPM Meeting, March 20thPRZM Hybrid Land Workability Approach:Additional ExamplesNot as accurateWaterborne Environmental, IncandSyngenta Crop Protection.11EMPM Meeting, March 20thPRZM Hybrid Land Workability Approach:Additi l E lAdditional ExamplesFairly AccurateWaterborne Environmental, IncandSyngenta Crop Protection.12EMPM Meeting, March 20thHow well do we predict applicationacross planting season??Waterborne Environmental, IncandSyngenta Crop Protection.13EMPM Meeting, March 20thPRZM-Hybrid vs. old “best available” approach (1)But still not perfect !!Waterborne Environmental, IncandSyngenta Crop Protection.14EMPM Meeting, March 20thPRZM-Hybrid vs Old “Best Available” Approach (2)Waterborne Environmental, IncandSyngenta Crop Protection.15EMPM Meeting, March 20thUsing PRZM-Hybrid to enhanceexisting monitoring dataWaterborne Environmental, IncandSyngenta Crop Protection.16EMPM Meeting, March 20thSequential PRZM HYBRID LogicGrab and AutosampleMeasured Conc.Data recordGrab and AutosampleMeasured Conc.Data recordWatershedVariablesRainfallGDD ApplicationWatershedVariablesRainfallGDD ApplicationDay withField sample?GDDApplicationWindowApplication DataSoilsWindowApplication DataSoilsApply rule.Add Grab/AutoData To DailySeriesYesModeledPRZMEOFPRZMEOFSeriesAdd PRZMEOFConc toFinal DailyCNoYesEOF Event ?EOFConc.EOFConc.EOFConc.toDaily SeriesAddInterpolateConc.Time SeriesNoAddInterpolatedvalue toDaily SeriesInterpolateLinearly tonext measuredvalueWaterborne Environmental, IncandSyngenta Crop Protection.17EMPM Meeting, March 20thPRZM-Hybrid Uses Local Soils/Rainfall to Drive Realistic Simulations ofPotential Events between Monitored Data.AC

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FlTime(t)lPRZM‐HybInterpolatedLinePRZM‐HybConc.MonitoredSampleConc.FlowSampleInterpolatedLineRainfallEventConclusionsPRZM-Hybrid shows considerable promise for supplementing 7-day dataPredicts peak occurrence/relative magnitude but overpredicts->20 ppbReflects reality - peaks only predicted when runoff events likely tooccurNew land workability approach provides improved estimates ofexpected atrazine application timingPRZM-Hybrid ties application together with local rainfall topp gestimate runoff using well established regulatory model algorithmIncorporates effect of degradation and “soaking” rainsModel output compared to measured values indicatesapproach improves on previous best available approachWaterborne Environmental, IncandSyngenta Crop Protection.19EMPM Meeting, March 20thPRZM-Hybrid - Next StepsEvaluate enhancing Land Workability approach for applicationdates with NASS planting progress dataEvaluate optimal approaches for larger CWS-relevant watershedsof area >800 sq. mi.Divide into smaller units and do simple routingApply a simple dilution modelDue to “area averaging”, transition from mechanistic to WARPmodelsApply PRZM Hybrid thinking to other types of Agrochemical usepatternsPreventative and curative fungicide applicationsInsecticide treatmentsEvaluate approaches for linking PRZM-Hybrid to Probabilisticweather data for evaluating year-to-year variationWaterborne Environmental, IncandSyngenta Crop Protection.20EMPM Meeting, March 20thThank youWaterborne Environmental, IncandSyngenta Crop Protection.21EMPM Meeting, March 20thWaterborne Environmental, Inc.andSyngenta Crop Protection21