Transcript Managing Manure for Crop Production when Feeding DDGS

Managing Manure for
Crop Production when
Feeding DDGS
Kyle Jensen
ISU Extension Field Specialist-Crops
Feeding DDGS Changes the
Manure Nutrient Content
 Crude Protein is higher
 Phosphorus is higher
 Rule of Thumb
 DDGS contain about 3 times the nutrient
analysis of corn
Corn and Soybean
requirements
 Nitrogen
 Phosphorus
 Potassium
 Calcium, Magnesium, Sulfur
 Fe, Mn, Zn, Cu, Ni, Mo, B, Cl
How Much N do I need
 Depends on the year
 Favorable growing conditions
 More N
 Unfavorable growing conditions
 Get by with less N
Maximum Return To N and Most
Profitable N Rate Range
Iowa - SC
160
$2.20/bu
0.05
0.10
0.15
0.20
Return to N, $/acre
140
120
100
$0.11/lb N
$0.22
$0.33
LOW
MRTN
HIGH
$0.44
80
60
40
20
0
0
50
100
150
N Rate, lb N/acre
200
250
Maximum Return To N and Most
Profitable N Rate Range
Iowa - CC
160
0.05
0.10
0.15
0.20
Return to N, $/acre
140
120
100
80
60
40
20
0
0
50
100
150
200
N Rate, lb N/acre
http://extension.agron.iastate.edu/soilfertility/nrate.aspx
250
How much P do I need
 Look at soil sampling results
 Try to stay in the optimum range
 11-20 ppm depending on subsoil amount
 Crop removal
 Corn –grain, silage, and/or stover
 Soybeans
Nutrient Content of
Harvested Crops
lb per Unit of Yield
Crop
Unit
P2O5
K2O
Corn
Bu
0.375
0.30
Corn Silage
Ton
3.50
6.50
Soybean
Bu
0.80
1.50
Alfalfa
Ton
12.50
40.00
Pm-1688 General Guide for Crop Nutrient Recommendations in Iowa
Current Grain P2O5
Removal
 Anywhere from 80-125# P2O5 per rotation
 Corn
 150 bu
 175 bu
 200 bu
56# P2O5
66# P2O5
75# P2O5
 Soybeans
 40 bu
 50 bu
 60 bu
32# P2O5
40# P2O5
48# P2O5
Long-Term Benefits From Agronomic
Application of Manure To Crop Land
 Improved productivity
 Improved fertility
 Essential plant nutrients
 Adds organic matter
 Stimulates biological activity
 Improves physical structure
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Infiltration
Stability
Water holding capacity
Bulk density
Nutrients in manure should be
managed with the same care as
commercial fertilizer
 We have to determine:
 Amount of nutrients in the manure
 Availability of the nutrients to the crop
 Amount of nutrients needed to optimize crop yields
 That manure is being applied uniformly
Determining the Nutrient
Content of Manure
 Have a certified lab test the manure
 Having a chemical analysis
 Needs to be done from representative
sample of manure
 Eliminates the question of what might be the
nutrient content of the manure
Plant availability of the
nutrients in animal manure
 Animal manure contains all the nutrients
essential for plant growth.
 The nutrients are present in both organic and
inorganic forms.
 The nutrients in inorganic form are readily available.
 The nutrients in organic form must be converted into
inorganic form. This conversion, mineralization, is
accomplished by microorganisms that live in all soils
Availability of nitrogen in
animal manure
 Nitrogen is present in both organic and
inorganic forms in animal manure.
 The total amount of N present and the
proportion of organic to inorganic N depends on
animal species and how the manure is handled
and stored.
 Recent research suggests:
 About 35% of the total N in dry cattle and dairy
manure is available to plants the year of
application
Nitrogen loss
 The two forms of inorganic N in animal manure are
ammonium (NH4+) and urea.
 If manure is left on the soil’s surface, ammonium
and urea will form ammonia gas and be lost to the
atmosphere (volatilization).
 You must make adjustments for volatilization
losses of N.
Use correction factors to account
for nitrogen volatilization during land
application of animal manure
 Correction factors to account for N volatilization during land
application of animal manures.
 Application Method
Correction Factor

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
Direct injection
Bdcst & incorp. w/in 24 hrs
Bdcst & incorp. after 24 hrs
Bdsct liquid, no incorp.
Bdcst dry, no incorp.
Irrigation, no incorp.
0.98
0.95
0.80
0.75
0.70
0.60
 Source: Iowa Department of Natural Resources
Availability of phosphorus
in animal manure
 P is present in both inorganic and organic
forms.
 If the soil test for P is “high” or “very high”
consider that 100% of the P is available.
 If the soil test for P is “very low,” “low,” or
“optimum” consider that 60% of the total
P will be available the year of application.
To determine a rate what
nutrient do I use?
 Manure application rates can be
determined using either N, P, or K needs.
 Depending on which set of regulations
you fall under, and P index value.
 N and P are used most frequently to
determine application rates.
Example of determining a
Rate
You have solid manure from a beef operation that contains 12
lb N, 6 lb P2O5, and 12 lb K2O per ton.
You have established that you can grow 175 bushels of corn per acre
on a field in southwest Iowa. Last year’s soybean crop yielded 50
bushels/acre.
N fertilizer = (175 x 1.2) - 50 lb N/acre
= 210 - 50 = 160 lb N/acre
Manure rate = 160 lb N/acre  2.9 lb N per ton
= 55 tons/acre
But did we over apply P
[55 tons x 6 lb P2O5/ton = 330 lb P2O5/acre]
Example of determining a
Rate (Problem)
You have solid manure from a beef operation
that contains 12 lb N, 6 lb P2O5, and 12 lb
K2O per ton.
But did we over apply P
[55 tons x 6 lb P2O5/ton = 330 lb P2O5/acre]
According to your P index can you apply
according to N requirements or P?
Tons of Manure vs.
Nutrient Need
Crop Nutrients from Cattle
Feedlot Manure with Rate
Based on Total N Application
Nutrient Removal in Grain Based
on 50 bu/acre Soybean and 175
bu/acre Corn Yields
Manure Application, tons/acre
Nutrient
10
18
55
- - - - - - - - lb/acre - - - - - - - - -
S-C
Soybean
Corn
Rotation
- - - - - - - - lb/acre - - - - - - - -
N
29
52
160
0
160(?)
160
P2O5
60
108
330
40
66
106
K2O
120
216
660
75
40
115
Example manure nutrient values for beef feedlot finishing, confined unit: 12 lb total
N/ton; 6 lb P2O5/ton; 12 lb K2O/ton. N available calculated at 2.9#/ton. About 11 tons
per head per year are produced, according to ISU Publication ICM – 1.
Concerns with DDGS
 From Table 2, “Use of Distillers Grain in
Feedlot Diets”
 15% DDGS in diet increases excreted P2O5 by 20%
 25% increases excreted by 40%
 40% increase by 70%
 Additional Concern regarding Application
Dry manure spreaders are not calibrated often enough
Dry spreaders aren’t always very uniform in
application.
Manure Application:
things to think about
 Fall applications allow time for organic portions of the
manure to mineralize.
 Fall applications also allow for more potential N loss to
the environment.
 To conserve N that is in the manure from loss
 Apply manure in the fall when the soil temperature (4” deep in
the soil) is 50o F and cooling.
 Applying manure to frozen soils increases the potential
for environmental contamination.
 N and P movement into surface water can be significant.
 Apply only on relatively flat land (slopes of 4 % or less).
 A little common sense will keep problems away
Feeding DDGS, How am I going
to change to accommodate
higher manure P
 Applying manure with higher P content
 Crop removal
 Soil test results
 Manure test results
 Higher P manure if applied by P requirements:
 Larger number of acres to apply
 Different/Better equipment to get to these acres?
(may be further away)
 More acres=more time
Summary
 Commercial fertilizer costs $
 $400 anhydrous 1#N is $0.24
 $340 11-52-0
1# P2O5 is $0.33
 $255 0-0-60
1# K2O is $0.21
 What your manure is worth in terms of nutrients and organic
matter = increased biological activity, better soil structure,
increased infiltration, increased water holding capacity, increased
pH buffering capacity
 Corn - Corn rotations will need more N and P than a traditional
Corn - Soybean rotation
 Use your resource and take credit for it
Questions-comments?