Value of Poultry Manure Nutrients for Crop Production
Antonio Mallarino and John SawyerDepartment of Agronomy
Nutrients for Crop Production
• Corn almost always needs N.• P and K are needed for low-testing
soils and to maintain optimum levels.• Manure can be used to supply N, P,
K, and other nutrients. It may also improve physical soil properties by supplying organic matter.
• But excessive or badly applied manure can impair water quality.
Issues for Manure Nutrients Use
• Nutrient concentration variability.• N-P-K ratios and crop needs.• Manure nutrient availability shortly
after application.• Expensive storage and handling,
difficulties for uniform application.• Soil-test variability in manured fields.• Producer's doubts about its value.• State/federal regulations for its use.
N & P Concentration of Solid Manures
0
20
40
60
80
Swinegrowfinish
Dairy &Beef
Layers Broilers Turkey
N
P205
Table Values in Pm 1811
A. Rieck-Heinz
Poultry Manure Nutrients
• No organic K, all soluble inorganic.• Variable proportion of inorganic and
organic N, P, and S. Organic forms must be mineralized to be absorbed.
• Mineralization rates vary with the handling and application methods, climate, and field conditions.
• Nutrient availability immediately after application is difficult to predict.
Ammonium - Organic N in Manures
0 20 40 60 80 100
Swine PitSwine Lagoon
Beef Feedlot
Liquid BeefComposted
Poultry
% Distribution
Ammonium Organic
Manure Nitrogen Availability
• Guidelines for 1st-year N availability compared with fertilizer (Pm 1811):- beef and dairy: 30 to 40%- poultry: 65%- swine: 100%
• N volatilization:- incorporation within 24 hrs 0.95- incorporation after 24 hrs 0.80- no incorporation at all 0.70
Phosphorus in Animal Manures
• 40 to 95% inorganic P, simple to complex compounds, highest values are for liquid swine manure.
• Phytase enzyme feeding may reduce total P by 25 to 35%.
• P water solubility varies a lot but isn’t a good index of availability.
• Iowa: 60% availability in low-testing soils and 100% for maintenance.
Poultry Manure Nutrients Utilization Project
Antonio MallarinoJohn SawyerDaniel KaiserDorivar Ruiz-DiazDavid WittryBrett AllenMazhar HaqDaniel Barker
18 producers' fields2004, 2005, and 200614 countiesLayers, turkeys, broilers
Poultry Manure Field Resehararch
Manure strips 01 2
Reps 1 2 3
2 20 0 11
3 manure rates applied to strips using farmer's or applicator's equipment.
4 N fertilizer rates and 4 P fertilizer rates to small plots. Uniform K rate and N or P rates as appropriate across P or N small plots.
Measured manure nutrients, early corn growth, grain, and soil-test values after harvest.
Manure Total N ConcentrationM
anur
e N
itrog
en (l
b N
/ to
n)
0
20
40
60
80
100
120PM 1811Tested Values
Layers TurkeyBroilers
Range
Manure Total P ConcentrationM
anur
e P
(lb P
2O5
/ ton
)
0
20
40
60
80
100
120 PM 1811Tested Values
Layers TurkeyBroilers
Range
Poultry Manure Nutrient Variation
Poultry Manure Sample Analyses (As-Is Basis)
-40
-30
-20
-10
0
10
20
30
40
0 10 20 30 40 50 60 70 80 90 100
Average Site Analysis (lb N, P2O5, or K2O/ton)
Indi
vidu
al S
ampl
e D
iffer
ence
Fro
m S
ite
Ave
rage
(lb/
ton)
Total-NTotal-PTotal-K
All Site AverageN: 63 lb N/tonP: 63 lb P2O5/tonK: 41 lb K2O/ton(18 sites, 108 samples)
Corn Response to Poultry Manure 7 to 68 bu/acre Response. Average 41 bu/acre
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Cor
n Yi
eld
(bu/
acre
)
60
80
100
120
140
160
180
200
220
2004 20062005
No manure Low manureHigh manure
Yields and Manure or Fertilizer NAverages Across All Responsive Sites
N Fertilizer Rate (lb N/acre)0 50 100 150
Yie
ld R
espo
nse
(bu/
acre
)
0
20
40
60
80
No manure
Manure high
Manure low
Low : 111 lb N/acre (44-172)High: 225 lb N/acre (104-336)
Average Manure-N Rates
High Uniform P and K Rates Applied
Canopy Greenness with SPAD MeterAverages Across All Responsive Sites
N Fertilizer Rate (lb N/acre)0 50 100 150
Can
opy
Gre
enne
ss R
eadi
ng
0
2
4
6
8
10
12
14
No manure
Manure high
Manure low
Low : 111 lb N/acre (44-172)High: 225 lb N/acre (104-336)
Average Manure-N Rates
High Uniform P and K Rates Applied
Late Spring Soil Nitrate Test
Soil Nitrate-N (ppm)0 10 20 30 40 50 60
Cor
n Y
ield
Res
pons
e (b
u/ac
re)
0
20
40
60
80
100
No manure
High manure rateLow manure rate
A good test only to tell whenwhen no extra N is needed
Poultry Manure N and Timing
Holmes and Rueber, ISU
Cor
n G
rain
Yie
ld (b
u/ac
re)
100
110
120
130
140
150
160
170
180
190
200
210
Control
82 lb Manure N
Winter
135 lb NSpring Urea
Spring
164 lb Manure N
Winter
Spring
Egg Layers ManureNorthern Research Farm3-year Averages
Recent Research: Poultry Manure N
• The N availability compared with fertilizer N is on average 50 to 60%.
• N volatilization:- Incorp. within 24 hrs 0.95 - 0.99- Delayed or no incorp. 0.70 - 0.80
• Long-term manure application increases soil organic matter and may increase N mineralization rates and N supply for crops.
Soil P Buildup After HarvestAverage Buildup: Low Rate = 14 ppm High Rate = 30 ppm
1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6
Soil
P B
uild
up (p
pm)
0
10
20
30
40
50
60
70
2004 20062005
Low manure rate High manure rate
Low : 136 lb P2
O5
/acre (90-198)
High: 258 lb P2
O5
/acre (168-346)
Low: 2.0 ton/acre (1.5-2.3)
High: 3.8 ton/acre (2.4-4.6)
Poultry Manure as a P SourceAverage Across Fields with Yield Response to Fertilizer or Manure P
P Fertilizer Rate (lb P2O5/acre)0 50 100 150
Cor
n Yi
eld
Res
pons
e (b
u/ac
re)
0
5
10
15
20
25
No Manure
Low Manure
High Manure
Low : 136 lb P2O5/acre (90-198)High: 258 lb P2O5/acre (168-346)
Manure and Manure-P Rates
Low: 2.0 ton/acre (1.5-2.3)High: 3.8 ton/acre (2.4-4.6)
Uniform N and K Fertilizer Applied
a
aa
aa
a
b
c
bb
Poultry Manure P and Early GrowthAverages Across All Fields
P Fertilizer Rate (lb P2O5/acre)0 50 100 150
Cor
n Ea
rly G
row
th (g
/pla
nt)
2.6
2.8
3.0
3.2
3.4
3.6
3.8
4.0
4.2
4.4
No Manure
Low Manure
High Manure
Summary: Poultry Manure P
• The P availability is higher than we thought: is 90 to 100%.
• Uncertainty on poultry manure P availability isn't as important as for N because much P is applied even by applying ½ of the N needed by corn.
• Major issues with poultry manure P are soil P buildup and uniformity of application for wet manures.
Manure N-P Ratios and Crop Needs
• N-based manure application often results in soil P build-up over time.
• Corn-soybean rotation:- Dairy & beef: small or no P buildup- Swine: small or no P buildup, may
be short of P when phytase is used.- Poultry: large P buildup, larger for
egg layers, less with phytase.• Corn after corn: very large buildup.
Egg layers manure assuming 35 lb of N and80 lb of P205 / ton:
Needs N-Based AppliedCrop N P205 Manure P205
180 bu Corn 150 lb 68 lb 4.3 ton 344 lb
60 bu Beans 0 lb 48 lb none 0 lb
Total: 116 lb 344 lb
Total P by applying just 1/2 of N need (75 lb) 172 lb
N-Based Egg Layers ManureCorn-Soybean Rotation P Need and Applied P
Large P build up, enough for 3 years
Egg layers manure assuming 35 lb of N and50 lb of K20 / ton:
Needs N-Based AppliedCrop N K20 Manure K20
180 bu Corn 150 lb 54 lb 4.3 ton 215 lb
60 bu Beans 0 lb 90 lb none 0 lb
Total: 144 lb 215 lb
Total K by applying just 1/2 of N need (75 lb) 107 lb
N-Based Egg Layers ManureCorn & Soybean K Needs and Applied K
Insufficient K (75%) for the rotation
Maximizing Manure N Use Efficiency
• Use manure analysis but be aware of high variability.
• Mineralize the most of organic N:- fall application allows more time but puts
inorganic nitrate-N at greater risk of loss
• Minimize ammonium volatilization:- immediate incorporation into the soil
• In-season tests for additional N:- late-spring soil nitrate and emerging tools
such as aerial photos and sensors.
Maximizing Manure P & K Use
• Use manure and soil analyses but be aware of high variability.
• Full N-based poultry manure rates apply excess P and K (for 2 or 3 crops), look at P Index over time.
• Phytase feeding reduces manure P. Good to balance nutrient content and allows for higher manure application rates and more use of manure N.
Nutrient Availability in Practice
• Manures are heterogeneous materials often difficult to handle.- high nutrient variability, difficult
application of uniform rates, high soil-test variability in manured soils
• These factors introduce much more uncertainty than for fertilizers and may reduce the usually assumed efficiency of manure nutrients.