1. Wheat Fertilizer Management
Wheat Growth and Development
4/19/2017
Wheat Fertilizer Management
Presentation by:
Chad Lee, Grain Crops Extension Specialist
University of Kentucky
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

2. Wheat Growth and Development
4/19/2017
Most of the information comes from: ID-125: A Comprehensive Guide to Wheat Management in Kentucky
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

3. Wheat Growth and Development
4/19/2017
Objectives
N rates
N timing
P and K
Other nutrients?
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

4. Three Critical Management Issues
Wheat Growth and Development
4/19/2017
Three Critical Management Issues
Seeding: Date, Depth, Rate
N Rate and Timing
Fusarium Head Blight
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

5. Wheat Growth and Development
4/19/2017
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

6. Wheat Growth and Development
4/19/2017
N Requirements
Fall: 20 to 40 lbs of N needed
Late Winter (mid-Feb): 30 to 50 lbs
Spring (Feekes 5, mid-March): remaining N
total late winter and spring applications should equal 60 to 100 lbs N/acre
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

7. Fall: 20 to 40 lbs N/acre needed
Wheat Growth and Development
4/19/2017
Fall: 20 to 40 lbs N/acre needed
Stimulates tiller development.
Usually enough residual N from preceding corn or soybean crop.
Important for late plantings and/or low stands (< 25 plants/ft2).
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

8. Late-Winter: 30 to 50 lbs N/acre
Wheat Growth and Development
4/19/2017
Late-Winter: 30 to 50 lbs N/acre
30 to 50 lbs N/acre (conventional till).
40 to 60 lbs N/acre (no-till).
Mid-Feb (about Feekes 3)
N stimulates tillering.
Poor stands need more N.
Adequate stands need less N.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

9. Late-Winter: 30 to 50 lbs N/acre
Wheat Growth and Development
4/19/2017
Late-Winter: 30 to 50 lbs N/acre
Caution
Excessive N can lead to increased lodging, disease, and damage from late spring freezes.
Need to scout fields and apply appropriate rate.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

10. Spring (Feekes 5): Remaining N
Wheat Growth and Development
4/19/2017
Spring (Feekes 5): Remaining N
Feekes 5: Psuedo-stem strongly erected; just prior to jointing.
Start of rapid N uptake at this point.
Be sure not to use too much N or lodging will be likely.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

11. Spring (Feekes 5): Remaining N
Wheat Growth and Development
4/19/2017
Spring (Feekes 5): Remaining N
Total late winter and spring applications should equal 60 to 100 lbs N/acre (conventional) and 90 to 120 lbs N/acre (no-till).
For wheat yield potentials greater than 70 Bu/Acre, total N should be 80 to 100 lbs/A.
Use 60 to 80 lbs N/A, total, for lower yield potentials.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

12. Single Spring N Application
Wheat Growth and Development
4/19/2017
Single Spring N Application
Split-application dates will yield 3 bu/acre more than single applications.
Logistics cause many farmers to choose the single spring application.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

13. Single Spring N Application
Wheat Growth and Development
4/19/2017
Single Spring N Application
Target Feekes 5 (mid-March).
Rate should be 60 to 90 lbs N/acre (conventional).
Rate should be 90 to 120 lbs N/acre (no-till).
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

14. Single Spring N Application
Wheat Growth and Development
4/19/2017
Single Spring N Application
Feb applications should only be made if tiller counts are low.
Single N applications made in Feb. promote excessive growth and earlier head development.
Increases the risks for late spring freeze.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

15. Wheat Growth and Development
4/19/2017
Late N Applications
N applications to N-deficient wheat at or after Feekes 6 (jointing) will result in yield losses.
N applications after Feekes 9 (flag leaf) will not increase yield but will increase protein concentration in seed.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

16. Wheat Growth and Development
4/19/2017
N Application Methods
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

17. Wheat Growth and Development
4/19/2017
N Application Methods
Liquid N delivery systems and airflow delivery for solid forms are more accurate than spinner systems.
Drop tubes will reduce N burn from liquid N.
Flood nozzles delivering water + liquid N (no more than 60 lbs N/acre) can reduce burning.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

18. Wheat Growth and Development
4/19/2017
Phosphorus
Critical for root development, tillering, early heading, grain fill, early maturity, and resistance to winterkill.
Wheat takes up 0.67 lbs of P2O5 for each bushel of grain.
80% of P2O5 taken up goes to grain.
Apply in fall before planting.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

19. Wheat Growth and Development
4/19/2017
Potassium
Helps lower the incidence of some diseases and adds to straw strength, reducing lodging.
Wheat takes up 2 lbs K2O for each bushel produced.
80% of K2O taken up goes to grain.
Apply in fall before planting; can be applied in the spring if necessary.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

20. Wheat Growth and Development
4/19/2017
Other Nutrients
Ca, Mg, and S deficiencies have not been observed in Kentucky.
Micronutrient deficiencies have not been observed in Kentucky.
Chad Lee © 2006 University of Kentucky
Chad Lee, University of Kentucky

21. Chad Lee © 2006 University of Kentucky