Return on
Investment of Your
Forage System
Fertilizer $$
By
Nick Schneider
Winnebago Co. WI,
Agriculture Agent
February 10, 2011
Nutrient Recommendation
Philosophies
Sufficiency Level: Soil test levels established & identified
by likelihood of a crop response, nutrient recommended
only for low through high soil tests. Fertilize the crop.
Similar to Build and Maintain: Fertilize the soil
Basic Cation Saturation Ratio: Concept that there is an
ideal ratio or range of catios that maximizes crop
production.
Soil Test Interpretation Categories
Probability
Soil Test
Level
Relative Supply of Nutrients From
Soil and Fertilizer
of Yield
Increase
Very
High
Soil
<5%
High
Soil
Soil
Optimum
Soil
Low
Very
Low
Soil
Nutrients available
from soil
Adapted from Havlin et al.,1999
using WI interpretations
Fert.*
F+M+L
Fert.+Manure+Leg
Fert.+Manure+Leg
5-30%
30-60%
60-90%
>90%
Nutrients required
* Fertilizers used at high soil test levels are
for starter or maintenance purposes
Nutrient Management
• Combine on-farm nutrient sources, with
commercial fertilizer, to meet crop need
On-farm nutrient sources
(manure and legumes)
Commercial fertilizer
Minimize nutrient losses
Manure Nutrient Credits
100
90
80
70
$ / acre
Economic value of
nitrogen,
phosphate, and
potash in 25
tons/acre of surface
applied, solid dairy
manure.
60
$96
50
40
30
20
$30
$37
10
0
N
P2O5
K2O
Manure Nutrient Content - Solid
First-year available nutrient content averages.1
SPECIES
N
P2O5
K2O
- - - - - - - - - - - lbs/ton - - - - - - - - - - -
Dairy
Beef
Swine
Chicken
Turkey
1 Source:
3 (4)2
4 (5)
7 (9)
20 (24)
20 (24)
3
5
6
30
24
7
9
7
24
24
Wisconsin soil test labs.
2 Use values in parenthesis for incorporated manure.
Manure Nutrient Content - Liquid
First-year available nutrient content averages.1
SPECIES
N
P2O5
K2O
- - - - - - - - - lbs/1,000 gal - - - - - - - - - -
Dairy
7 (10)
Beef
5 (7)
Swine (indoor pit)
25 (33)
Swine (outdoor pit)
17 (22)
Swine
13 (16)
(nursery indoor pit)
Poultry
8 (10)
1 Source:
5
5
25
10
14
6
16
16
24
16
18
10
Wisconsin soil test labs.
2 Use values in parenthesis for incorporated manure.
Micronutrients in Dairy Manure
Nutrient
Calcium
Magnesium
Sulfur
Iron
Boron
Copper
Manganese
Zinc
Lb per ton
5
2
1.5
0.1
0.01
0.01
0.03
0.04
Lb per 1000 gal
14
6
4.2
0.3
0.03
0.03
0.08
0.11
Nitrogen Credits for Alfalfa
Medium or Fine
Textured Soils
> 8 inches
regrowth
< 8 inches
regrowth
NITROGEN CREDIT
- - - - - - - lbs N/acre - - - - - - -
Alfalfa Stand Density
Good >70%
190
150
Fair
160
120
130
90
30-70%
Poor <30%
80% for Red Clover
Concepts of Fertilizer Efficiency
Economic Optimum Rate
Maximum Return to Nutrient
Income Over Fertilizer (feed) Cost
Relative Yield (Expressed as a Percentage)
Delta Yield (Change in Yield)
Fertilizer Use Efficiency
Luxury Consumption
Corn Silage
Bob Kaiser “Typically high forage diets cost less.”
Wisconsin “PEPS” Program
Corn Silage
2006
La
nd
C
he
m
ic
al
In
te
re
st
O
th
er
2009
Fe
rt
il
Eq ize
r
ui
pm
en
t
H
ar
ve
st
Se
ed
$200
$180
$160
$140
$120
$100
$80
$60
$40
$20
$0
Economic Optimum N Rate
Cost of last
increment
of
N added
=
Value of
yield
increase
produced
N Guidelines for Corn
• Maximum Return to N (MRTN)
– Flexibility in rates based on economics
• Cost of N
• Price of corn
• Cropping systems approach
– Corn after soybeans, small grains
– Corn after corn, forage legumes, green manures, etc.
• Multi-state, regional approach
– WI, IA, IL, MN, OH, IN, MI
Nitrogen:Corn Price Ratios
Price of N1
- $/lb N -
2.50
2.75
3.00
3.25
3.50
3.75
4.00
4.25
4.50
0.25
0.10
0.09
0.08
0.08
0.07
0.07
0.06
0.06
0.06
0.30
0.12
0.11
0.10
0.09
0.09
0.08
0.08
0.07
0.07
0.35
0.14
0.13
0.12
0.11
0.10
0.09
0.09
0.08
0.08
0.40
0.16
0.15
0.13
0.12
0.11
0.11
0.10
0.09
0.09
0.45
0.18
0.16
0.15
0.14
0.13
0.12
0.11
0.11
0.10
0.05
0.50
0.20
0.18
0.17
0.15
0.14
0.13
0.13
0.12
0.11
0.10
0.55
0.22
0.20
0.18
0.17
0.16
0.15
0.13
0.13
0.12
0.15
0.60
0.24
0.22
0.20
0.18
0.17
0.16
0.14
0.14
0.13
0.20
0.65
0.26
0.24
0.22
0.20
0.19
0.17
0.16
0.15
0.14
0.70
0.28
0.25
0.23
0.22
0.20
0.19
0.18
0.16
0.16
0.75
0.30
0.27
0.25
0.23
0.21
0.20
0.19
0.18
0.17
0.80
0.32
0.29
0.27
0.25
0.23
0.21
0.20
0.19
0.18
Price of Corn ($/bu corn)
1
Price of N = [$/ton fertilizer x (100 / % N in fertilizer)] / 2000
Corn Nitrogen Rate Calculator
http://extension.agron.iastate.edu/soilfertility/nrate.aspx
Profitable N Rate
Profitable N Rate
• A range of N
rates can
produce
profitable yields
• Economics
drives the
profitable N rate
Corn Starter
•
-
If fields are in a responsive range, starter pays
But on high fertility soils?
100 sites in WI with high fertility
Average Starter 15-26-32
9-23-30 costs $461
100 lbs/a, $23/a
Needed 5.75 bu at $4 corn
Or 2/3 ton wet silage
Laboski, 2009
Grass-Legume
Research
at
Marshfield
Treatments
1. Untreated
2. Nitrogen (N) = 130 lbs/a. 4-Year Total $242/a
3. Phosphorus (P) = 30 lbs/a P2O5. 4-Year Total $58/a
4. Potassium (K) = 210 lbs/a K2O. 4-Year Total $353.50/a
5. Managed grass pasture (N+P+K). 4-Year Total $630.05/a
6. Managed legume/grass pasture + micronutrients (K+B+Ca+S).
4-Year Total $475.75
7. Manure: 2 tons/acre after each harvest.
$0.45/lb nitrogen, $0.35/lb phosphorus, $0.45/lb potassium, $4.50/lb
boron, $0.10/lb gypsum (supplied calcium and sulfur), and $4 per
application dry fertilizer application.
Replicated – 4 Years – 3 to 4 ton yield goal
Manure Credits on Pasture
Manure Estimate
50 cows X 106 lbs manure/day= 5,300 lbs manure/day
5,300 lbs manure/day * 5 days= 26,500 lbs or 13.25 tons
Reduce for time in the barn (25%) = 10 tons
10 tons / 2 acres = 5 tons solid manure/acre/year
Fertility Credit
5 tons solid manure/acre X 3 lbs N/ton = 15 lbs/acre
X 3 lbs P2O5/ton = 15 lbs/acre
X 7 lbs K2O/ton = 35 lbs/acre
Soil Analysis
pH
Organic Matter %
2006
2007
2010
2006
2007
2010
Untreated
6.7
6.5
6.2
2.8
2.7
2.6
N
6.5
6.5
6.2 *
2.9
2.9
2.8
N+P+K
6.9
6.7
6.0
2.9
2.9
3.0 *
P
6.8
6.6
6.2
2.9
2.8
2.7 *
K
6.8
6.6
6.3
2.9
2.9
2.6
K+B+Ca+S
6.9
6.7
6.3
3.0
2.9
2.8 *
Manure
6.8
6.7
6.2
2.9
2.9
2.9 *
* = unchanged from 2006 to 2010 at P=0.10
Soil Analysis
Potassium
Phosphorus
2006
2007
2010
2006
2007
2010
Untreated
56
42
45 *
31
26
19
N
54
33
39 *
33
25
19
N+P+K
52
55
71
30
26
23
P
60
41
49 *
31
28
28 *
K
53
55
160
30
25
19
K+B+Ca+S
50
63
114
31
26
19
Manure
55
47
62 *
31
27
19
* = unchanged from 2006 to 2010 at P=0.10
Soil Analysis
Boron
Calcium
Magnesium
Sulfur AI
2006
2007
2010
2006
2007
2010
2006
2007
2010
2006
2007
2010
UT
0.8
0.9
0.4
1050
1095
1057
303
273
263
38
29
38
K+B+S
+Ca
0.8
1.1
0.8
1105
1155
1133
325
285
270
37
32
39
Sward Density – Spring 2009
Figure 2: Percent Clover in Sward, May 27, 2009
Percent Clover (dry matter)
50
40
A
AB
AB
30
AB
BC
20
CD
10
D
0
K+B+Ca+S
K
P
Manure Untreated N+P+K
N
Yield Response
Nitrogen
Untreated
May 2009
Manure
Potassium
May 2009
Forage Quality
Untreated
N
N+P+K
P
K
K+B+Ca+S
Manure
Average
P-Value
LSD (0.05)
Untreated
N
N+P+K
P
K
K+B+Ca+S
Manure
Average
P-Value
LSD (0.05)
C. Protein
19.6 ab
18.7 c
18.5 c
19.5 ab
19.4 ab
19.8 a
19.2 b
19.3
0.0003
0.5
C. Protein
19.6 a
16.6 b
17.2 b
18.8 a
18.9 a
19.0 a
19.4 a
18.5
<0.0001
1
NDF
37.0 b
39.5 a
39.4 a
37.4 b
37.7 b
37.4 b
37.8 b
38.0
0.0001
0.9
Forage Quality Measurements
Low Fertility Location, Harvests 8/21/06 to 11/1/07
Ne
TDN
Ca %
K%
RFV
0.718 a
175.7 a
69.5 a
1.05 a
1.94 c
0.711 b
162.8 b
68.7 bc
0.77 c
1.81 c
0.705 c
163.0 b
68.3 c
0.75 c
2.64 a
0.715 ab
174.3 a
69.3 ab
1.01 ab
2.00 c
0.712 b
171.8 a
68.9 b
1.02 a
2.47 ab
0.713 ab
173.6 a
69.1 ab
1.01 ab
2.55 a
0.713 ab
171.7 a
69.1 ab
0.95 b
2.25 b
0.71
170.4
69.0
0.94
2.24
0.0054
0.0002
0.0048
<0.0001
<0.0001
0.006
5.4
0.5
0.07
0.23
Mg %
0.43 a
0.39 b
0.33 c
0.43 a
0.39 b
0.37 b
0.38 b
0.39
<0.0001
0.03
P%
0.31 c
0.33 bc
0.31 bc
0.36 a
0.32 bc
0.32 bc
0.34 b
0.33
0.0068
0.024
NDF
33.3 b
37.4 a
38.5 a
34.6 b
35.2 b
35.2 b
34.4 b
35.5
0.0005
2
High Fertility Location, 11/1/07 Harvest Only
Ne
TDN
Ca %
K%
RFV
0.77 a
208.0 a
74.2 a
0.69 a
3.03 bc
0.75 bc 180.7 cd 72.6 bc
0.54 bc
2.90 c
0.76 c
174.8 d
72.3 c
0.46 c
3.33 a
0.76 ab
198.8 ab
73.7 a
0.74 a
2.96 c
0.75 ab
194.2 bc
73.5 ab
0.70 a
3.33 a
0.76 ab
194.4 b
73.5 ab
0.68 a
3.23 ab
0.76 ab
199.6 ab
73.6 a
0.61 ab
3.11 abc
0.76
193
73.4
0.63
3.10
0.0162
0.001
0.0055
0.0042
0.0082
0.01
13.6
0.9
0.14
0.25
Mg %
0.18
0.17
0.15
0.18
0.17
0.16
0.16
0.17
0.0998
NS
P%
0.42
0.40
0.35
0.39
0.39
0.39
0.40
0.39
0.5469
NS
Economic Return Over Fertilizer
4-Year Totals
Untreated
N
N+P+
K
$821
$1067
$1192
$893
$1015
$1075
$1030
0
242
630
58
353
475
0
Value-Cost
825
562
835
662
600
1030
Return Compared to
Untreated
$4
$-259
$14
$-159
$-221
$209
Forage
Value
Fertilizer
Cost
P
K
K+B+Ca
+S
Manure
Compare the price of fertilizer to hay when making fertilization decisions.
Nitrogen Fertilizer Management on
Rotationally Grazed Pastures
Dennis Cosgrove and Ken Barnett
Yield Increases from Nitrogen Application
Species
KB
SB
OG
Control
Yield
(lbsDM/a)
4365
5293
4654
May 1 +
June 15
+ Aug 1
Yield Increase (lbs DM/acre)
246
14
232
710
885
1326 456 1002
1054
2019
1052 516
729
1062
1284
June
May 1 +
May 1
Aug 1
15
June 15
Potassium in Alfalfa
Alfalfa Response on a Withee Soil, 1998-2001
Annual K2O
Rate
Soil Test K2O
Average
Annual
Yield
Feed Value
K20 Cost
Return
Compared
to Untreated
lbs/A
136 ppm initial
T/a DM
$120 Ton/dm
$0.45/lb
$
0
69
3.47
$416.40
$0
100
84
3.95
$474.00
$45
+$12.60
200
123
3.96
$475.20
$90
-$31.20
400
266
4.22
$506.40
$180
-$90.00
Over fertilizing is expensive
What effect does delaying potash
application have on soil test level?
No additional K
applied after
spring 2006.
Laboski, 2009
Tissue Testing
Tips for High Priced Fertilizer
per “The Big Laboski Hour”
Lime is the cornerstone of a good soil fertility program
Tips for High Priced Fertilizer
per “The Big Laboski Hour”
• The first increment of nutrients applied has the
greatest efficiency and potential for economic return
For P and K
1. Use manure credits first
2. Apply fertilizer to responsive fields first
3. Fertilize high fertility fields at a lower rate
4. Lastly- starter on very high fertility fields