Field trial design requirements for all trials:

Traditional field trial design
  • Corn grown and harvested for grain only
  • Field length strips preferred, minimum of 30 feet wide by 600 feet in length
  • Account for all nitrogen sources including manure, alfalfa, legume credits in addition to starter, MAP and DAP
  • Rate trials should maintain a minimum 30 lb N/acre rate separation for comparison. Dealer nitrogen program comparisons are also acceptable.
  • Keep all other factors
    Advanced rate field trial with six rates replicated three times.
    Advanced rate trial design
    consistent across field trial area (hybrid/variety, other nutrients, rates, soils, field history, drainage, topography, equipment)
  • Crop adviser submits information to verify accuracy (If a farmer does not have a crop adviser, please contact closest NMI
  • representative for assistance.)

*See NMI Guidelines for a complete listing of field trial requirements.


Examples and additional requirements are listed below. Farmers and crop advisers can suggest other field trials, new ideas in precision agriculture are strongly encouraged. The field trial should have the potential to provide benefits to improving farm performance and reducing nitrogen losses.


Preplant: Urea 150 lb N/acre vs 120 lb N/acre
Side dress: 28% UAN 20 gal (60 lb N/acre) vs (30 lb N/acre)
Dealer Nitrogen Programs comparisons (Greenseeker, VRT, Adapt N, Climate Corp, 360 Yield Center)

Nitrogen rate additional requirements

  • For best results, only use N sources without additional nutrients in the formulation when applying the different rates. Applications of starter, AMS, MAP, DAP, or blends of products should not be used for the nitrogen rate difference.
  • 30 lb N/acre minimum rate separation
  • No manure or alfalfa history within the past two years for this trial


Preplant: Urea 60 lb N/acre vs 30 lb N/acre
Side dress: 28% UAN 20 gal (60 lb N/acre) vs 10 gal (30 lb N/acre)
Evaluate first and/or second year manure nitrogen credits

Nitrogen rate after manure additional requirements

  • Use the same commercial nitrogen source applied at a different rate only following manure (30 lb N/acre minimum rate separation)
  • Use the same manure source, rate and application method over the field area
  • Account for manure source, analysis, application rate, and appropriate credits in the Crop Management Form
  • Current manure test for nitrogen should meet current local and state permitted standards 


N-Serve, Instinct, ESN, Agrotain

Nitrogen stabilizer additional requirements

  • Use the same nitrogen rate, source, timing, and placement for both treatments
  • Comparisons between different stabilizer products, or blends of products, can be used as long as all other inputs are consistent
  • Read and follow the stabilizer label for the recommended application rates
  • Manure applications with a stabilizer are eligible. Provide manure information on Crop Management Form. Please contact NMI Representative first


    Fall vs Spring
    All Preplant vs Side dress/Split

    Nitrogen timing additional requirements

    • For best results, use the same nitrogen source applied at a different time
    • Use the same equipment for both treatments applied at a different time only
    • Manure applications are eligible. Provide manure information on Crop Management Form


    UAN vs Anhydrous Ammonia

    Nitrogen source additional requirements

    • Use the same nitrogen rate, source, timing, or stabilizer applied with a different nitrogen source only
    • For best results, using the same nitrogen placement is preferred
    • Contact NMI Representative with other suggestions
    These sites are newer to the program. They are designed to answer questions that farmers have about nutrient management and to inform the University of Minnesota’s current nitrogen fertilizer recommendations.

    Additional compensation is available for farmers and crop advisers participating in advanced rate trials. Participating farmers are compensated $1,500 and crop advisers are compensated $700 for each field trial.

    Advanced trial additional requirements

    • Must have corn-corn or corn-soybean rotation history
    • No manure or alfalfa history in the last 5 years
    • Install a minimum of 1 test strip at least 30 ft wide, and 1/2 mile long or multiple test strips equivalent to a 1/2 mile (2640 ft)
    • Nitrogen rate test strips contain 5-6 unique N rates and each N rate replicated 3 times
    • 40-50 lb difference between N rates
    • Must include zero rate check strip (check strip can only include N contributions from DAP or MAP applications)
    • Soil types, topography, drainage, and field history should be consistent across the trial area
    • Variable rate technology (VRT) and yield monitors to aid in field trial design, installation, and harvest

    Examples of additional trials include:

    • Nitrogen rate following alfalfa

    • Cover crops