Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the Environment Nitrogen Uptake in Corn and Wheat
                                                                                                                                    Quick links: Causes of Plant to Plant Variability in Yield within Corn Production Systems  National Corn Growers Association Yield Contest Results




CORN


  The above graph shows results over 2 years (6 total sites in Oklahoma) where corn forage N uptake can be predicted from growth stages ranging from V8 to V10.  However, it should be noted that this was from by-plant data (NDVI and N uptake determined by-plant).

 

Total N uptake from V6 to VT, Lake Carl Blackwell, 2006

  Results from Iowa on larger plots showed that by the V12 growth stage in corn, 90 kg N /ha was accumulated in the plant, which is over 1/2 the total amount found by VT (point of maximum N accumulation).  Thus, because forage N uptake can be predicted (graph above), the use of this information for projecting N rates based on predicted yields should have merit.  Similar data from Oklahoma (graph directly below), show the same result, whereby more than 50% of the total N accumulated had taken place by V10.

 

Nitrogen uptake in corn, Iowa

 

 



CORN Facts and Figures

Reeves, D.W., and J.T. Touchton. 1989. Nitrogen uptake by corn in a winter legume conservation-tillage system. USDA-ARS. National Soil Dynamics Laboratory. Auburn University, AL.

Nitrogen uptake in corn, Canada

Nutrient uptake and partitioning in corn and potatoes in Manitoba.  2004. Manitoba Agric. Food and Rural Initiatives.

  Wright, David, Jim Marois, Jim Rich, and Richard Sprenkel. 2002. Field corn production
       guide. University of Florida, IFAS Extension, Gainesville, FL.
  • 1.2 to 1.3 lbs of N required per bushel.
  • 20-25 % of N needs applied at Planting.
  • Remaining N needs should be applied side dress.
  • No yield increases have been found from N applications after silking.
  • Corn takes up 15 lbs N/ac by the time it is 15 inches tall.
  • It will grow to 3 feet tall in the next two weeks and take up about 80 lbs N/ac during those 2 weeks, followed by another 50 lbs/acre in the next two weeks prior to tassel emergence.  Therefore, at least 130 lbs N/ac will be needed in the four weeks after corn reaches the 15 inch height.

Francis, D.D., J.S. Schepers, and M.F. Vigil. 1993. Post-anthesis nitrogen loss from corn. Agron. J. 85:659-663.



Average number of days to reach the different corn growth stages (4 locations in Oklahoma), 2005

WHEAT

N uptake, 40 bu wheat (2.72 Mg/ha) = 40*60 = 2400 lbs * 0.0235 = 56.4 lb/ac = 63.2 kg/ha
 
Journals
  Increased plant N loss with increasing nitrogen applied in winter wheat observed with 15N       J.Plant Nutr. 23:219-230.
 Effect of nitrogen rate on plant nitrogen loss in winter wheat varieties
     J. of Plant Nutr. 20 (2&3):389-404.
  Nitrogen accumulation in shoots as a function of growth stage of corn and winter wheat.  2010. J. Plant Nutr. 33:165-182.  Girma, K., S. Holtz, B. Tubana, J. Solie, and W. Raun. 2010.

   Freeman, K., et al., Long-Term Effects of Nitrogen Management Practices on Grain Yield, Nitrogen Uptake and Efficiency in Irrigated Corn (Zea mays L.). 2007. J. Plant Nutr. 30:2021-2036.