EFFECTIVE NUTRIENT MANAGEMENT USING NITROGEN BMPs Central MN Sands

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EFFECTIVE NUTRIENT MANAGEMENT USING NITROGEN
BMPsCentral MN Sands

• Dept. of Soil, Water, and Climate
• University of Minnesota-St. Paul

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Why Such an Issue?Sensitivity to Environment

• Phosphorus and its impact on surface
• Sedimentation into lakes and streams
• Overall air quality
• Nitrogen in water supplies

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Why Such an Issue?N Management Factors

• Application timing
• Product selection
• Application rate
• Application method

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Why Such an Issue?Over-application of N Rate

• Balance between yield and loss
• Minimize losses in each system

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Nitrogen BMPsStatewide Guidelines

• Set realistic yield goals
• Use recordkeeping system
• Use a soil N test, if applicable

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Soil N Test Recommendation

• Measures N from
• Extra fertilizer
• Leftover fertilizer
• Residual manure
• 2nd Yr Legumes
• NOT useful on most sandy soils

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Nitrogen BMPsStatewide Guidelines

• Set realistic yield goals
• Use recordkeeping system
• Use a soil N test, if applicable
• Adjust N for all N sources
• Use 2nd year N credits

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Legume Credits
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Nitrogen BMPsStatewide Guidelines

• Prudent manure management
• Calibrate
• Test
• Apply uniformly
• Inject/Incorp.
• No run-off

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Nitrogen BMPsRegions of Minnesota

• Southeast
• South-central
• Southwest/West Central
• Northwest
• Central/East Central

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Nitrogen BMPsRegions of Minnesota

• Rainfall patterns
• Primary factor in regional differences
• Soil differences
• Textures affect N management
• N/Water movement

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Nitrogen BMPsRegional Guidelines

• No fall N on coarse soils
• Sidedress or split N applications
• Incorporate urea w/in 3 days
• Inject/incorporate sidedress N

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Central/EC N BMPs

• 3-Yr study by Schmitt et al.
• Non-irrigated, sandy loam soil
• No splits used
• Nitrate found 5 deep in fall

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Nitrogen BMPsIrrigated Soil Guidelines

• No fall nitrogen
• Use water mgmt. strategies
• Test and adjust for N in water
• Establish cover crop if early

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Nitrogen BMPsIrrigated Soil Guidelines

• Use sidedress/split N
• Dont rely solely on fertigation
• Use NI with preplant/early side N
• Include starter N
• Dont delay N after uptake period

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Irrigated Soils N BMPs

• Multi-year study by Malzer et al.
• Fertigation study on sandy soil

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UM Fertilizer N Rates

• Corn
• Potatoes
• Edible beans

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UM N Rates-Corn, lb/a
Assumes low OM, coarse-textured soils
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UM N Rates-Ed. Beans, lb/a
Assumes low OM, coarse-textured soils
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UM N Rates-Potatoes, lb/a
Assumes low OM, coarse-textured soils
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Nitrogen BMPsMinimizing Risks

• Soil testing for N
• Plant (petiole) N testing
• Integrated N management plan
• Optimize crop production management

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Nitrogen BMPsSummary

• BMPs are for everyones benefit
• BMPs are research-based
• Research is continuing today
• Input is welcome