Producer:Projector Contract: Location: County: Farmname: Tractnumber
Producer:Projector Contract: Location: County: FarmName: TractNumber:
Onthemap, delineatethecontour baseline(s),correctionareas,andstableoutletsforconcentratedflow.
Descriptionofwork:
NRCSReviewOnlyDesignedBy: / Date:
CheckedBy: / Date:
ApprovedBy: / Date:
Draft TNNRCS
September 2014
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ThePracticePurpose(s):
Reducesheetandrillerosion.
Reducetransportofsediment,other solidsandthecontaminantsattachedtothem.
Reducetransportofcontaminantsfoundinsolutionrunoff.
Increasewaterinfiltration.
Site PlanningConditionsfor theDominant CriticalSoilMap Unit/ComponentPlanningMapUnit/Component / PlanningSlope % / PlanningLengthofSlope(ft) / PercentAbsoluteContourRowGradePlanned
Maximum andMinimumContourRowGrades
Minimum Contour RowGrade(Percent)
The crop rows shall have sufficient grade to ensure that runoff water does not pond and cause unacceptable crop damage. / Maximum Contour RowGrade(Percent)
Themaximumrowgradeshallnot exceedone-halfoftheup-and-downhillslopepercentusedforconservationplanningwith a maximum 2 percentrowgrade. Upto a25-percent deviationfromthedesignrowgradeis permittedwithin150feetofastableoutlet.
MinimumTillageRidgeHeightsand In-RowPlantSpacing
Rowspacinggreaterthan10inches / Rowspacing10inchesorless / NoTillagePlanting
Theminimumridgeheightshallbe2inchesduringtheperiodoftherotationthatismostvulnerabletosheetandrillerosion / Theminimumridgeheightshallbeoneinchforclose-growncrops,suchassmallgrains. Plantheightshallbeatleast6incheshighandthespacingbetweenplantswithintherowshallnotbegreaterthan2inchesduringthetimemostvulnerabletosheetandrillerosion. / Nominimumridge height
Critical Slope Length:A contour farming layout shall not occur on a hill slope that is longer than the critical slope length, unless supported by other practices (e.g. terraces, diversions) that either reduce slope length below the critical length or reduce overland flow velocities.
CorrectionsAreas:Wherefieldoperationsbegintoconvergebetweentwonon-parallel contourbaselines,establishacorrectionareathateitheris permanentlyinsod,establishedtoanannual close-growncrop.
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Draft TNNRCS
September2014
OPERATIONAND MAINTENANCE
Perform alltillageand planting operationsparallel tocontour baselines or terraces,diversions, or contourbuffer stripboundarieswherethese practicesareused,providedtheapplicablerowgradecriteriaaremet.
Where terraces,diversions, or contour bufferstripsarenotpresent,maintaincontour markers on gradesthat,when followedduring establishmentofeachcrop,willmaintain croprows at designedgrades.Contour markersmaybe fieldboundaries,acroprowleftuntilled nearoronanoriginalcontourbaselineorother
readilyidentifiable,continuous,lastingmarker. Alltillageandplanting operationsshall be paralleltothe established marker.If amarker islost,re-establish a contourbaselinewithintheapplicablecriteriasetforthbythis standardpriortoseedbedpreparationforthenext crop.Itmaybeusefultocapturethebaselinecoordinates withaGPSsotheycaneasilybere-establishediflost.
Farmingoperationsshouldbeginonthecontour baselinesandproceedbothup anddowntheslopeinaparallelpatternuntilpatternsmeet.Wherefield operationsbegintoconvergebetweentwonon-parallelcontourbaselines,establishacorrectionareathateitheris permanentlyinsod,establishedtoan annual close-growncrop.
Where contour rowcurvaturebecomestoosharptokeep machineryalignedwithrows duringfieldoperations,establishsodturnstrips onsharpridgepoints or otheroddareasas needed.Avoidmowing,spraying,ormachineryusageson sodareastopreventtrackingandrutting.
Draft TNNRCS
September 2014Page 3 of 3