Late Season Nitrogen Application: On-farm Research - Mark Badertscher, OSU Extension, from the 2020 Conservation Tillage and Technology Conference, held March 3-4, 2020, Ada, OH, USA.

1. Late Season Nitrogen
Application –
On-Farm Research
Mark Badertscher – OSU Extension, Hardin County
Conservation Tillage Conference – Ohio Northern University
March 3, 2020

2. Nitrogen 4 Rs
• Source –
• Fertilizer - DAP 18-46-0, MAP 11-52-0, Urea, 28% UAN,
anhydrous ammonia, manures
• All are subject to loss – volatilization, denitrification, leaching
• Rate –
• Corn – MRTN, choose the rate on an economic basis
• Look to the future to combine soil data, zone management
and optical sensors
• Time –
• Apply nearer to time of crop use, no fall applications, use split
applications
• Place –
• Incorporate into the soil, below the surface, or into a standing
crop

3. Economic Based N Rate Calculator
Maximum Return to N (MRTN)
• Current Ohio Nitrogen Recommendation Tool
• Most profitable N Rate
• Regional Approach to Nitrogen Rate Guidelines
• Uses a yield response combined with the price of corn and nitrogen
considered
• Web Based
http://extension.agron.iastate.edu/soilfertility/nrate.aspx

4. Run MRTN with
Ohio Conditions
• Information Needed
• Location: Ohio
• N price: $0.50/lb
• Corn price: $3.50/bu
• Rotation: C-S
• MRTN Rate (lb N/acre): 157
• Profitable N Rate Range: 143-173 ($1)
• Percent of Maximum Yield at MRTN Rate:
97%

5. Hardin County Nitrogen Rate Trials
2016 – Mineral Soil + 28 lbs N starter 2016 – Muck Soil + 0 lbs N starter
lbs N Sidedress Bushels per Acre lbs N Sidedress Bushels per acre
0 lbs Nitrogen 71.67 bu/acre a 0 lbs Nitrogen 186.00 bu/acre a
100 lbs Nitrogen 131.03 bu/acre b 100 lbs Nitrogen 190.93 bu/acre b
150 lbs Nitrogen 141.20 bu/acre c 150 lbs Nitrogen 189.80 bu/acre b
200 lbs Nitrogen 148.10 bu/acre c d 200 lbs Nitrogen 190.70 bu/acre b
250 lbs Nitrogen 151.93 bu/acre c d 250 lbs Nitrogen 189.17 bu/acre b

6. Nitrogen Timing
• How much N do we need at
planting vs. at tassel?
• Can we delay our application?
• Can we split our application?
• What do we need for risk
management?

7. Nitrogen
Uptake by
Corn
Total N uptake and
partitioning across four
plant fractions: leaf, stalk,
reproductive, and grain
tissues.
Each value is a mean of six
hybrids across two site-
years at Urbana, IL (2010)
and DeKalb, IL (2010).
GDDF = growing degree
days (˚F).
Figure 2. Total maize N uptake and partitioning across four plant
stover fractions: leaf, stalk, reproductive, and grain
tissues. Each value is a mean of six hybrids across two
nutrient and micronutrient uptake and
Urbana, IL and DeKalb, IL (2010).
t Removed
with grain
Harvest
index, %
Nutrient removal
coefficient, lb/bu
b/A - - - - - -
148 58 0.641
180 79 0.351
159 33 0.261
113 57 0.061
1114.4 62 0.019
1110.3 23 0.001
d in oz (i.e. oz/A and oz/bu).
f six hybrids at both locations (mean = 230
as calculated as the ratio between nutrient
d total nutrient uptake and is reported as a
yield by Nutrient Removal Coefficient to obtain
250
225
200
175
150
125
100
75
50
25
0
NUptake,lbN/A
Percentoftotal,%
GDDF
Growth Stage
0 500 1,000 1,500 2,000 2,500
VE V2 V4 V6 V10 V14 VT/R1 R2 R4 R5 R6
100
75
50
25
0
Grain
Tassel, Cob, Husk Leaves
Stalk and Leaf Sheaths
Leaf Blades

8. Soil Scan Field Testing

9. Soil Scan Field Testing

10. Soil Scan Field Testing

11. Crop Color Sensors

12. Crop Color Sensors

13. Crop Color Sensors

14. Corn Stalk Nitrate Test

15. Corn Stalk Nitrate Test
End-of-season stalk nitrate test
“report card” to determine whether N was over - or under-applied

16. Hardin County Nitrogen Timing Trials - 1
Treatments Placement Rate
(total N/ac)
Source CSNT
(ppm)
2016 Yield
(bu/ac)
Yield
Difference
(bu/ac)
NUE
(lbs N/bu)
2017 Yield
(bu/ac)
Check
0 N Sidedress
Y-Drops ® 147 Urea
DAP
AMS
28% UAN
N/A 172 a - .85 N/A
60 lb
28% UAN
@ V6
Y-Drops ® 207 Urea
DAP
AMS
28% UAN
N/A 187 a +15 1.11 N/A
60 lb
28% UAN
@ V8
Y-Drops ® 207 Urea
DAP
AMS
28% UAN
N/A 185 a +13 1.12 N/A
60 lb
28% UAN
@ V10
Y-Drops ® 207 Urea
DAP
AMS
28% UAN
N/A 179 a +7 1.16 N/A
60 lb
28% UAN
@ V12
Y-Drops ® 207 Urea
DAP
AMS
28% UAN
N/A 176 a +4 1.18 N/A

17. Hardin County Nitrogen Timing Trials - 2
Treatments Placement Rate
(total N/ac)
Source CSNT
(ppm)
2016 Yield
(bu/ac)
Yield Difference
(bu/ac)
NUE
(lbs N/bu)
2017 Yield
(bu/ac)
Check
60 lb N Plant
135 lb N
Sidedress
Coulter
Injection
195 28% UAN N/A 146 a + 1.34 N/A
Split
60 lb N Plant
105 lb N
Sidedress
36 lb N Late
Sidedress
Coulter
Injection
Y-Drops ®
201 28% UAN N/A 147 a +1 1.37 N/A

18. Fulton County Nitrogen Timing Trials - 1
Treatments Placement Rate
(total N/ac)
Source CSNT
(ppm)
2017 Yield
(bu/ac)
Yield Difference
(bu/ac)
NUE
(lbs N/bu)
2016 Yield
(bu/ac)
Check @ V5 Coulter/Knife 210 28% UAN 58 233 a - .90 219 a
Late N @ V12 Drops 210 28% UAN 449 235 a +2 .89 219 a
Split @ V5 &
V12
Both 210 28% UAN 1,375 239 a +6 .88 222 a
Late N @ V12
(reduced)
Drops 168 28% UAN 173 220 b -13 .76 N/A

19. Fulton County Nitrogen Timing Trials - 2
Treatments Placement Rate
(total N/ac)
Source CSNT
(ppm)
2017 Yield
(bu/ac)
Yield Difference
(bu/ac)
NUE
(lbs N/bu)
2016 Yield
(bu/ac)
Check @ V5 Y-Drops ® 210 28% UAN 831 223 a - .94 174 a
Late N @ V10 Y-Drops ® 210 28% UAN 1,048 218 a -5 .96 176 a
Late N @ V10
(reduced)
Y-Drops ® 168 28% UAN 57 218 a -5 .77 176 a
Late N @ V10
(reduced)
Y-Drops ® 126 28% UAN 20 207 b -16 .61 N/A

20. Fulton County Nitrogen Timing Trials - 3
Treatments Placement Rate
(total N/ac)
Source CSNT
(ppm)
2017 Yield
(bu/ac)
Yield Difference
(bu/ac)
NUE
(lbs N/bu)
2016 Yield
(bu/ac)
Check @ V5 Gas Injection 210 Anhydrous 458 209 a - 1.0 212 a
Late N @ V12 Drops 210 28% UAN 972 212 a +4 .99 211 a
Split @ V5 &
V12
Both 210 Both 1,633 214 a +6 .98 214 a
Late N @ V12
(reduced)
Drops 168 28% UAN 148 211 a +3 .80 N/A

21. Reduce the risk of N loss
Make no surface application of nitrogen
• Incorporate, inject, band
• Apply an inhibitor if early application (NH4) or surface applied (UAN or urea)
Delay the application
• Apply 30 to 60 units of N at plant, then sidedress the remainder
• Or - apply 100 N as NH4 before planting, then use a crop sensor in season or apply the last 20, 40 or 60N as
a sidedress application – for your total nitrogen required
Rotate crops
• Corn after soybeans uses about 40 lb/A less N
If using manure, apply when the crop can use the N
• Apply in spring – incorporate & consider as an in-crop application
• Account for the available N in manure – offset commercial N applications
Consider a grass cover crop – to capture excess N

22. Questions?
badertscher.4@osu.edu
419-767-6037