Institute of Ag Professionals
Proceedings of the
2013 Crop Pest Management Shortcourse &
Minnesota Crop Production Retailers Association Trade Show
www.extension.umn.edu/AgProfessionals
Do not reproduce or redistribute without the written consent of author(s).
Realistic Expectations for the Use
of Starter Fertilizer for Corn
Daniel Kaiser
Assistant Professor
Department of Soil,
Water and Climate
U of M Twin Cities
612-624-3482
[email protected]
2013 CPM Short Course
Terminology
• Starter Fertilizer: over reaching term
– Traditionally means 2x2 or a band with the
planter away from the seed
• In-Furrow or “Pop-up”
– Placement of fertilizer directly on the seed
• Surface band
– Band on of fertilizer applied directly on the soil
surface (sometimes called 2x0)
Background
• Dry fertilizer was the norm many years
ago
• Liquid sources have become popular with
larger planters
• Economics are different
– Dry fertilizer tends to be less $ per lb. of
nutrient
– Easier to make a custom blend with dry
• Liquids are sold in many different analyses
Starter – Benefits
Both real and theoretical
1. Faster early plant growth (highest
probability)
2. Increased nutrient uptake early in the
season
3. Decreases the time to silking
4. Decreased grain moisture at harvest
5. Increases in Grain Yield (lowest
probability)
Early Growth
• Increase in plant height or mass as a
direct result of fertilizer application
• Realization
– Increased early growth does not mean that
there will be an increase in grain yield
• How should we view early growth
– Insurance that the crop will get to V5 faster
Days to Silking versus Corn
Planting Date
Location
Planting
Date
No Starter
+ Starter
-----------days---------Lamberton
Waseca
Early
77
75
Middle
68
67
Late
62
61
Early
76
74
Middle
67
66
Late
63
62
Early, late April; Middle, early May; Late, late May.
Starter rate was 5 GPA 10-34-0
2010-2012 Data
Starter use resulted in
1-2 day reduction in
time to silking
Reduction was greatest
for the early planting
date
St. Charles 5-Year Average (2009-2013)
Morris 5-Year Average (2009-2013)
150
130
Corn Grain Yield
Early Plant (V5-V8) Growth
Relative Increase (% of control)
140
130
120
110
100
90
80
Corn Grain Yield
120
110
100
90
lb
lb s/c
AP s/s orn
P+ oy
80 be
a
/s
oy n
be
an
80
80
N
o
G
PA P
AP
P
5
80
lb
lb s/co
s
AP
rn
/
P+ soy
80 be
a
/s
oy n
be
an
80
80
N
o
G
PA P
AP
P
lb
lb s/c
AP s/s orn
P+ oy
80 be
a
/s
oy n
be
an
80
N
o
G
PA P
AP
P
5
80
lb
lb s/co
s
AP
rn
/
P+ soy
80 be
a
/s
oy n
be
an
80
5
N
o
G
PA P
AP
P
80
5
Relative Increase (% of control)
Early Plant (V5-V8) Growth
Lamberton 5-Year Average (2009-2013)
150
Corn Grain Yield
140
130
120
110
100
90
lb
lb s/c
AP s/s orn
P+ oy
80 be
a
/s
oy n
be
an
80
80
N
o
G
PA P
AP
P
5
lb
lb s/c
AP s/s orn
P+ oy
80 be
a
/s
oy n
be
an
80
80
N
o
G
PA P
AP
P
80
5
Relative Increase (% of control)
Early Plant (V5-V8) Growth
• Early growth responses can vary by
site
• St Charles: large EG response and
not yield response
• Morris: little EG effect from starter
and increased grain yield from
Broadcast P
• Lamberton: Large EG response
from broadcast and starter and no
yield differences between sources
Choosing the Right Product
Effects on Early Plant Growth
15 Location average (2008-2010)
10 lbs N, 20 lbs P2O5, 20 lbs K20 2x2 band
V5 Corn Mass (grams/plant)
6.5
a
P favors increased
early growth
a
6.0
b
b
b
r
r te
nly
nly
b
N can increase
growth but not as
consistently as P
5.5
5.0
4.5
4.0
S
No
ta
K
o
N
o
N
+P
N
+K
N
+P
+K
No Additive effect
Choosing the Right Product
Effects on Early Plant Growth
Corn Grain Yield (bushels/acre)
15 Location average (2008-2010)
10 lbs N, 20 lbs P2O5, 20 lbs K20 2x2 band
210
200
ab
a
bc
ab
Yield increase is
typically dictated
by a deficiency
a
Higher EG does
not result in Higher
yield
c
190
180
No
ar
St
ter
K
on
ly
N
on
ly
N
+P
N
+K
+K
P
+
N
K may effect Yield
Placement Options Should
Match with Products Applied
• “Pop-Up”
– Higher rates of P and K (?), low N and S
• Surface Band
– Mobile nutrients (N and S), little value to
immobile nutrients (P, K, and possibly micros)
• 2x2, 2x1, etc.
– Higher rates of total fertilizer, N and S
– At least 1” away from the seed is ideal
June 21, Waseca
193 bu/A, 21%
209 bu/A, 16%
Three-year Summary: Waseca
• Applying 4 gal/A of APP in-furrow
– did not affect grain yield (very high STP sites, not high pH).
– reduced grain moisture in 2 of 3 yr and for the 3–yr avg.
– increased plant height and/or dry matter yield in 3 of 3 yr and
the 3-yr avg., also reduced CV of height (3-yr avg.).
• Applying 8 gal/A of UAN as a surface dribble band
–
–
–
–
reduced grain moisture in 2 of 3 yr.
did not affect corn grain yield
increased plant height and DM yield in 3 of 3 yr and 3-yr avg.
trended CV of plant height lower (3-yr avg., P value = 0.118)
• Applying ATS in a surface dribble band
– reduced grain moisture at 1 of 3 yr
– increased grain yield in 1 of 3 yr (4 bu/A avg.)
– increased plant height and/or DM yield in 3 of 3 yr & 3-yr avg.
Three-year Summary: Rochester
• Applying 4 gal/A of APP in-furrow
– Increased grain yield in 1 of 3 yr and decreased in 1 of 3 yr
– reduced grain moisture in 2 of 3 yr
– increased plant height and/or dry matter yield in 3 of 3 yr
• Applying 8 gal/A of UAN as a surface dribble band
– reduced grain moisture slightly in 1 of 3 yr
– did not affect corn grain yield
– increased plant height in 2 of 3 yr and for the 3-yr avg.
• Applying ATS in a surface dribble band
– reduced grain moisture only for the 3-yr avg.
– increased grain yield in 1 of 3 yr
– slightly reduced CV of plant height (3-yr avg.)
Take Home
• May not be a right or wrong answer as to
what to use
• May be a particular nutrient combination
that is better, or more likely to increase
yield
• Consider the following
– Crop rotation
– Soil test values
– Tillage/soil type
Starter versus Broadcast
• Minnesota guidelines suggest that banded
P is more available and rates can be
reduced over broadcast
– This applies to Very Low and Low P soils
• Starter P (or K?) could be used to
supplement broadcast fertilization
– Greater early growth
– Increased yield versus broadcast alone?
Yield Response to Liquid Starter
or Broadcast P Fertilization
Grain Yield Response (%)
14
Starter
Broadcast
Broadcast + Starter
<16 ppm Soil P
(Very Low to Low)
12
10
8
6
16-20 ppm Soil P
(Optimum)
>20 ppm Soil P
(High to Very High)
4
2
0
Kaiser and Mallarino, 2005
Grain Yield Response (%)
Effect of residual fertilizer
applications on 2nd year soybeans
24
22
20
18
16
14
12
10
8
6
4
2
0
Grain Yield Response
<16 ppm Soil P
(Very Low to Low)
16-20 ppm Soil P
Starter
Broadcast
Broadcast + Starter
(Optimum)
>20 ppm Soil P
(High to Very High)
Increasing Trend, but was not considered significant
Kaiser and Mallarino, 2005
P-K Starter versus Broadcast
2011
2012
2013
Corn
Corn
Soybean
----------------bu/ac---------------No fert.
184a
141b
44b
Broadcast P-K
187a
154a
47a
No Starter
184b
150a
46a
Starter
188a
150a
46a
• Lamberton, MN
• Broadcast and starter
applied before each corn
crop
• Corn-Corn-Soybean
rotation
• 5 gpa 3-18-18
• 80 lbs P2O5 + 80 lbs K2O
broadcast before corn
*Response to starter for the first corn
**Response to broadcast P and K for the second corn and soybean crop
***Soil test was medium-high for both P and K
Net Return to PK Starter
Lamberton, MN 2011-2013
Gross Return
Corn1
Corn2
Fertilizer Cost
SB
Corn1
Net
Corn2
--------------------------------------$/ac-------------------------------------No Fert.
$0
$0
$0
$0
$0
$0
Starter
$20
$0
$0
-$30
-$30
-$40
Broadcast
$0
$52
$30
-$56
-$56
-$30
Broadcast
+ Starter
$20
$52
$30
-$86
-$86
-$70
• 4$/bu corn; 10$/bu soybean; 0.40/lb P2O5; 0.30/lb K20; $6/gal 3-18-18
• Broadcast: 80 lbs P2O5 + 80 lbs K2O; Starter: 5 gpa 3-18-18
Strip Trial Starter Data 2012-2013
Corn Grain Yield @ 15.5%
P
Site
Broadcast
APP (10-34-0) Rate (GPA)
0
2.5
5.0
Olsen
7.5
----------------------bu/ac---------------------Gaylord
Stewart
Janesville
New Richland
Willmar
No*
180
187
189
189
Yes
191
188
190
189
No*
222
229
226
227
Yes
230
233
235
234
No
190
191
193
198
Yes
198
192
194
194
No*
206b
215a
220a
217a
Yes
222
222
227
223
No*
139
147
144
150
Yes
173
172
169
167
P Broadcast: No, 0 lbs P205; Yes, 120 lbs P205
STP
-ppm14
13
19
10
7
Relative Corn Yield (% of Max.)
Starter Response Based on Initial
Soil Test P 2012-2013
110
No Starter no P
2.5 GPA APP
5 GPA APP
7.5 GPA APP
Grain Yield was not
increased when
broadcast was
applied
Broadcast P
2.5 GPA APP + Broadcast
5 GPA APP + Broadcast
7.5 GPA APP + Broadcast
Starter had the
greatest effect when
soil P was Low
100
90
80
No Broadcast + Broadcast
Low STP
No Broadcast + Broadcast
No Broadcast + Broadcast
Medium STP
High STP
2.5 gallons resulted in
highest yield for Med
And High STP
classes
*Ongoing study
Broadcast versus Starter
• Rate and product source significantly affect
economics
• Starter can increase yield, but not more than
broadcast alone
• For low testing soils, yield response favors
broadcast P
– Much of the data has not necessarily included high
pH soils
• What would happen when using a combination
of starter rate and broadcast?
– Remember you are applying nutrients with starter
Seed Safe Rates
• Starters can result in damage from:
– Salts
– Nitrogen, specifically ammonia, liberated
• Crops vary in tolerance
– Corn is relatively tolerant depending on the
source
– Soybean has a low tolerance to seed placed
fertilizer
In-Furrow ATS - Corn Emergence
Percent Corn Emergence (% of total)
14 days after initial emergence
100
80
60
40
Soil Type
20
Le Sueur CL
Zimmerman FSL
Port Byron SL
0
0
5
10
15
Nitrogen Rate Applied (lbs N/ac)
20
In-Furrow ATS - Corn Dry Matter Produced
14 Days After Emergence
Total Above Ground Plant Weight
(mg per flat)
8000
Soil Type
Le Sueur CL
Zimmerman FSL
Port Byron SL
6000
4000
2000
0
0
5
10
15
Nitrogen Rate Applied (lbs N/ac)
20
Damage
Index
Combination
Of
Early
Growth
Plant Stand
Salt Index
unit
=
Salt Load
=
Fert. Rate x
Salt Index
Recalculated for ATS and 9-18-9
9-18-9 considering only N
Considering N + S in ATS
“Seed Safe” Rates
assuming nominal soil moistures-Salt Load Model
Items of Interest – Greenhouse Study
• Loam soils, EG favored products
containing P
– Best results were at low rates applied at 2.5
or 5 lbs of N per acre
• Sand, EG favored fertilizers containing K
and S – P effect was significant but small
– K soil test was low and SOM was <1.0%
– Small increase in growth with ~1 gpa KTS
• I still would not recommend it
Comments on Seed Safe Rates
• ‘Salt Load’ model provides a way to base
rates or products if we know the salt index
– Different salt indexes out there; Mortvedt
calculation is used in the models shown
• I am still nervous about suggesting rates
of ATS, Urea, KCl, or 28% on the seed
• Some discrepancies in my calculations
from others when it comes to 9-18-9
– Some low salt mixes use Urea to increase %N
My Parting Comments
• Decisions need to be made with producer
goals in mind
– Realistically, the probability of a yield
response is not high in many situations
• Take a look at what is actually being
applied
– Total nutrients applied per $ of product
• Yield increase is proportional to the most
limiting nutrient
Targeted Approach
• Poorly drained soils
– Some data suggests broadcast is better
• Situations were “fallow syndrome” is likely
– Following sugar beet or brassica cover crops
• Rented ground
– Looking for high return on investment
• Early growth – 10-20 lbs P2O5 should be
enough
1. How many total nutrients and I buying
2. Where should I invest money within my
fertility program
1. Broadcast fertilizer
2. Higher priced per lb nutrient liquid fertilizer
Realistic Expectations
• In my experience, depending on
circumstances
– Grain yield response to starter 10-15% of the time
in high P testing soil or when broadcast was
applied ~ 5 bu/ac
– Grain moisture response is more likely
• Average 0.5% decrease, but may be as high as 1-1.5%
(this is rare)
• Starter (banded) K may give a higher chance
for return but may not be economic
Thank You
Questions?
SW&C Field Crew
Jeff Vetsch
Cooperators and Consultants
Daniel Kaiser
University of Minnesota
612-624-3482
[email protected]
http://www.z.umn.edu/nutmgmt
http://www.z.umn.edu/fbnutmgmt