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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Chad Lee © 2006 University of Kentucky