Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the Environment Nitrogen Fertilization Methods
World Nitrogen Use Efficiency for Cereal Production is 33%,
Agronomy Journal 91:357
Split Applications of Nitrogen-

     Sidedress Thoughts, Dr. George Rehm (University of Minnesota)

     Split N in Winter Wheat (Washington State University)

     Split versus Preplant Application of Nitrogen for Corn (Gyles Randall, UM)

     Recommendations from Dr. George Rehm (University of Minnesota)

      Corn Production as Affected by Nitrogen Application Timing and Tillage
           (Vetsch and Randall, Agron J. 96:502-509)

NEW N Management Strategy for Corn and Wheat

Nitrogen Fertigation
  • Preplant Nitrogen    

             IPNI comparisons (Scott Murrell)


Data from Iowa below for preplant N
Iowa State Fertilizer N Response, EONR

Optimum yield versus optimum N rate, at 77 Iowa sites, $3.75 corn, $.33 AA, C/C Rotation. 

  • “In a surprising finding, these (nitrogen) experiments showed no relationship between optimum corn yields and the amount of nitrogen needed to produce those yields.”

  • “The soil supplies unpredictable amounts of N” •“Plant available N varies widely from year to year”

Corn & Soybean Digest January 2007, data and quotes from
    University of Minnesota
    University of Illinois
    University of Wisconsin
    Iowa State University

Iowa State EONR in Corn
Sawyer et al. (2006) "Concepts and Rationale for Regional Nitrogen Rate Guidelines for Corn"

Ohio State Preplant Nitrogen Optimum N Rates

Lahoma Data (NDVI)                                             Lahoma Data (Yield)

EONR versus wheat grain yield, experiment 502, Lahoma, 1971-2008

Foliar Nitrogen

  Foliar N in Chickpeas

  Foliar N in Apples

  Foliar N in Citrus

    Influence of late-season foliar nitrogen applications on yield and grain nitrogen in winter wheat   


Trimble Pocket Sensor, Greenseeker, NDVI, nitrogen