1. Three Key Considerations in Planning Your 2019 Soil Fertility Program
Dave mengel
Professor Emeritus
Soil Fertility and crop production
Department of agronomy
Kansas State University

2. Three Key Things to Consider for 2019
Soil Testing: Key for making efficient and effective fertilizer recommendations.
Starter fertilizer: Starter placement is a great way to apply low rates of nutrients for corn.
Very important at low P, K, S and Zn soil test levels
When planting into cold soils: Early, No-till, or in poorly drained soils.
Important to apply some N to support early growth when N is knifed in preplant, or when sidedressing with no broadcast N.
Care must be taken to avoid stand issues or seedling injury.
Apply N efficiently, following the 4-R’s
Right Time
Right Source
Right Placement
Right Rate
SxTxP all interact with soils and weather to determine the right Rate-

4. Some Points on Cost Effective Soil Testing
Tests to request when soil testing:
Surface 6 to 8 inch samples, OM, pH, P, K and Zn
Profile 0-24 inch samples, N, S, Cl
Soil sampling system to use:
In variable or sloping soils, sample by soil type or landscape position
In uniform soils, consider grid sampling
The goal should be management zones which consider:
Soil variability
Past management impacts
Yield potential and crop removal

5. Dividing the Field Based on Soils or Topography
Topography makes good ‘management zones’ in many areas.
In many cases represents soils also
Sampling areas should represent a “treatable” area, 5-20 acres in size.

6. Systematic Grid Sampling Systems
Two sampling approaches:
Grid point
Grid average
Normal grid size varies
from 1 to 5 acres
200 x 200 = roughly 1 acre
300 x 300 = roughly 2 acres

7. Starter Fertilizer
No-till 2 x2 unit

8. Planting Time Fertilization
Traditional starter fertilizer applications for corn
Generally focused on supplying part of the P and K at low ST
Starter N can be equally as important:
In no-till into wide C:N residues
When the main N application is banded as NH3 or UAN
How starter N is applied is critical
Starter N can cause salt and/or ammonia damage to seedlings
In-furrow isn’t an option when adding high rates of N
Think 2x2 or surface banding to protect seeds/seedlings
Think outside the box for starter placement

9. Splitting P between Broadcast and Starter Band at Low ST
Elliot soil - High Productivity, Low Fertility

10. Response to Starter Fertilizer Across Tillage Systems
Responses > 5 bu
Mean
Response
If one
Mean Response
Across 11exp
Conventional
1/11 12
1.1
No-till
8/11 10
7.9
Mean of 11 studies using 2x2 starter fertilizer
and a direct tillage comparison. All done at P ST >20 ppm

11. More than P may be involved with starter

12. Effect of Primary N Placement on Starter Fertilizer Response
Yield, bu/a
No Starter
N Starter
Broadcast at planting
162
165
Preplant Inject
163
179
Bray P1 ST >40 ppm, No P applied in starter, 20 lb

13. Different Types of Starter Fertilizer Band Applications
‘2 x 2’ Starter
‘2 x 0’ Surface Band or Dribble
‘Pop-up’ or In-Furrow
Seed
Seed
Fertilizer
Fertilizer
Fertilizer

14. Starter Effects on Corn Yield (bu/a) 3-year avg, NCK Experiment Field
In-furrow
2x2 Side Band
2x0 Dribble
No Starter
159
5-15-5
172
194
190
177
197
198
174
216
212
171
215
213
163
214

16. Plant Population

17. Take Home Ideas About Starter
Great way to apply low rates of fertilizers for N, P, K, S, and micronutrients.
Consider using starter when planting early, planting no-till, or in cold wet soils.
Use very low rates, less than 6-10 pounds N + K, when placed with the seed to avoid salt or ammonia injury.
At low P and K levels soil test levels (<10 ppm P), apply 25% of the recommended rate, as a starter.
Apply pounds N at planting if balance of N banded preplant or sidedressed.

18. Nitrogen Fertilization Using the 4-R’s
Right Rate
Right Source
Right Time
Right Place

19. Right N Timing Timing is the traditional tool to address N loss due to
Leaching
Denitrification
Ammonia volatilization
Alternatives can include:
nitrification inhibitors
controlled release products (ESN)
Urease inhibitors

20. V-12
V-6

21. February urea on surface 159 February ESN on surface 179 Urea V-2 191
Response to Time of Application, Controlled Release Fertilizers and Nitrification Inhibitors in No-till Corn,
Treatment Yield, bu/a
No N
February urea on surface 159
February ESN on surface 179
Urea V
Urea V-2+ Agrotain
Urea/ESN blend 201
Weber and Mengel, 2009

22. Late Sidedress N Application on Corn
Treatment
N Rate lb/ac
Grain Yield bu/ac
Pre-plant N 60
133 e
Pre-plant N + 30 at V-8 90
158 d
Pre-plant N + 60 at V-8
120
173 c
Pre-plant N + 90 at V-8
150
185 bc
Pre-plant N + 30 at V-16
166 cd
Pre-plant N + 60 at V-16
192 b
Pre-plant N + 90 at V-16
206 a
Tucker and Mengel, KSU Agronomy North Farm, 2009

23. Two Recent N Management Studies

24. 2013, 2014 & 2015 Rainfall at Scandia Kansas
Time Period
Total Rainfall
inches
Total Rainfall inches
2013
2014
2015
Jan, Feb, Mar
1.85
2.05
2.78
April, May, Jun
10.3
12.62
14.7
July, Aug, Sept
8.98
7.15
5.45
Oct, Nov, Dec
3.85
4.77
3.27
Annual total
24.98
23.74
29.92
Longterm Average
30.60

25. Effects of Nitrogen application timing on irrigated corn yield, 2013-2015, Scandia, KS
Starter
At Planting
At V-4
At V-10
At R1
Total N
2013 Yield
2014 Yield
2015 Yield 20
161 cd
160 h
152 60 80
167 bcd
192 g
187
120
140
180 ab
211 ef
201
180
200
181 ab
216 de
217
178 ab
202 fg
188
229 abc
216
190 a
230 ab
208
179 ab
195 g
189
202
183 ab
205
184 a
218 bcd
176 abc
223 abcd
213
Rainfall
24.98
23.74
29.92

27. 2013, 2014 & 2015 Rainfall at Rossville Kansas
Time Period
Total Rainfall
inches
Total Rainfall inches
2013
2014
2015
Jan, Feb, Mar
4.11
1.79
2.68
April, May, Jun
11.05
11.63
16.59
July, Aug, Sept
11.93
8.69
13.99
Oct, Nov, Dec
4.83
5.51
3.73
Annual total
31.09
27.90
36.31
Long term average
37.09

28. Effects of Nitrogen application timing on irrigated corn yield, 2013-2015, Rossville, KS
Starter
At Planting
At V-4
At V-10
At R1
Total N
2013 Yield
2014 Yield
2015 Yield 20
197 g
97 e 72 60 80
217 def
165 bcd
118
120
140
235 abc
151 cd
151
180
200
234 abcd
175 abc
154
219 cdef
139 d
123
240 a
168 bc
182
239 ab
187 ab
186
221 cdef
154 cd
117
215 ef
172 abc
147
207 fg
188 ab
159
231abcde
183 ab
167
224 bcdef
193 ab
156
Rainfall
31.09
27.90
36.31

29. Poorly Drained Soils Prone to Denitrification

30. “System” Yield 150 UAN on surface 120 150 UAN knifed in 162
Building an efficient system for high residue no-till corn in a poorly drained soil
“System” Yield
150 UAN on surface
150 UAN knifed in
50 surface+100 SD
50 PP knifed in
100 SD Knifed in

31. Take Home on NUE
For the maximum NUE & profitability from N timing, try to minimize the potential time between application of N and uptake.
Use some early N, like starter if applying primarily sidedress to avoid early N stress.
Follow the 4-R’s for N Management
Remember, the 4-R’s interact
Right Rate
Soil Test
Right Source/Additive combination
N loss mechanism key
Right Timing
Drainage and soil texture key
The key tool for avoiding leaching on sands or denitrification on poorly drained soils such as clay pans.
Right Placement
Tillage/Residue/N Source (urea or UAN) the key to avoid volatilization.

32. Questions?

34. Influence of Tillage and Seed-Placed Starter Fertilizer on Corn Growth and Yield
Treatment
Population
Plant Height
Grain H2O
Yield
Tillage
Plow
23,900 a
47 a
31.8 b
156 a
No-till
22,100 b
44 b
33.7 a
155 a
Starter
No Pop-up
23,500 a
45 b
33.2 a
153 b
Pop-up
22,800 b
48 a
32.4 b
158 a
Pre-plant rate
23,000 a
32.8 a
152 b
23,300 a
32.7 a
159 a
Pop-up fertilizer rate was 6 gal per acre

35. We Don’t Have a Plant Taking Up N Early or Late in the Year
Biological activity in the soil begins days before corn takes up large amounts of N (V-6).
Biological activity in the soil continues days after corn stops taking up N in the fall.

36. Flooding and N efficiency
N Source Time of Flooding
Weeks after Applying N
-----percent yield ---- NH
UAN
120 pounds N applied sidedress
4” water applied

37. CO2 N2
NH3
C Fixation
N Fixation
Volatilization
Cereal Summer crop
Legume
Cover Crop
Fertilizer
Crop residue
C:N
Dynamic Soil
Organic Matter
Pool
Recalcitrant Soil
Organic Matter
Pool
NOx
Uptake
Decomposition
Immobilization
Mineralization
NH4+
Nitrification
Denitrification
NO3-
Immobilization Mineralization
Hi C:N Low C:N
Inorganic Pool
NH4 & NO3
Leaching

38. Impact of Soil Test and Starter Fertilizer N on Corn Yield
lb N/acre

39. Right Time

40. 2013, 2014 & 2015 Rainfall at Scandia Kansas
Time Period
Total Rainfall
inches
Total Rainfall inches
2013
2014
2015
Jan, Feb, Mar
1.85
2.05
2.78
April, May, Jun
10.3
12.62
14.7
July, Aug, Sept
8.98
7.15
5.45
Oct, Nov, Dec
3.85
4.77
3.27
Annual total
24.98
23.74
29.92
Longterm Average
30.60

41. 2013, 2014 & 2015 Rainfall at Rossville Kansas
Time Period
Total Rainfall
inches
Total Rainfall inches
2013
2014
2015
Jan, Feb, Mar
4.11
1.79
2.68
April, May, Jun
11.05
11.63
16.59
July, Aug, Sept
11.93
8.69
13.99
Oct, Nov, Dec
4.83
5.51
3.73*
Annual total
31.09
27.90
36.31*
Long term average
37.09
*(Dec not posted)

42. Key Points in Soil Testing

43. Residual and Applied N versus Grain Yield
Asebedo and Mengel, 2014