Placement of Nitrogen During Sidedressing

Trial Overview

  • Nitrogen (N) placement and its effect on N uptake and potential yield is a management concern of farmers.
  • Nitrogen is a major investment in corn production. Knowing where to place sidedressed N can help farmers decide which method of application is best for their operation.
 

Research Objective

  • The objective of this study was to determine if an advantage exists for placing N at the base of the plants vs. down the center of the row at the V6 growth stage (six leaf collars).
Location
Soil Type
Previous Crop
Tillage Type
Planting Date
Harvest Date
Potential Yield
Planting Rate
Monmouth, IL
Silt Loam
Corn
Conventional
04/25/2017
09/28/2017
290 bu/acre
36,000 seeds/acre

Site Notes:

A 114 RM SmartStax® RIB Complete® corn blend product was planted.The N form used for all treatments was 32-0-0 UAN.
         - 80 lbs/acre was applied before planting and incorporated.
         - 100 lbs/acre was sidedressed with a urease inhibitor.
Two sidedress application methods were used on 6/16/17 when plants were at the V6 growth stage.
         - A rolling coulter with a shallow knife in the center of the row (Figure 3 - top right).
         - 360 Y-Drop® (Figure 3 - bottom pictures).
The trial consisted of 4 replications.The data from 2016 was added to show 2 years of data.

 

 

Understanding the Results

 
Figure 1. Average Yield in 2017 for Center-Row Coulter vs. 360 Y-Drop® Application Methods
 
Figure 2. Two-year (2016 and 2017) Average Yield for Center-Row Coulter vs. 360 Y-Drop® Application Methods
  • The average yields for both methods were similar in 2017 (Figure 1).
  • The two-year average yields for both methods are similar (Figure 2).
  • Application at the V6 growth stage by either method showed no clear advantage.
  • Rolling coulter applications should be made before plant height exceeds toolbar height.
     
     
     
     
     
     
  • Individual corn products may respond differently to application timing.
 

What Does This Mean for Your Farm

  • The use of a rolling coulter with a shallow knife is limited due to corn height.
  • 360 Y-Drop® applicators allow a wider application window and are not limited to early-season sidedressing.
  • The ideal placement of sidedressed N could change from year to year due to weather and environment.
  • Individual products may respond differently to the timing of N application. Consult your local seed specialists for recommendations.
  • Yield differences may not be economically feasible when all costs are considered. Local costs should be evaluated when making N management decisions.