Hay Fertility Management
Sarah Kenyon
Agronomy Specialist
Houston, MO
Slides Prepared by: Brie Menjoulet
Nutrient Movement & Retention
• Is dependent on:
– The nutrient itself
– Overall soil health
– Soil texture (sand, silt
and clay composition)
– Organic matter
fraction
– Fertilizer type
– Application method
• You can improve some nutrient retention factors
Phosphorus (P) and Potassium (K)
• Chemical forms change in soil
• Plants uptake:
– Phosphorus as phosphate - P2O5
– Potassium as potash - K2O
• Not prone to leaching
• Clings to soil particle and organic matter
• Can be built up in the soil over time
Nitrogen (N)
• Complex cycle!
N 2O
NO
N2
N2
N 2O
NO3-
NO
NO2NH4+ & NO3-
NO3-
NH4+
NO3NO2-
Nitrogen (N)
• Complex cycle!
• Forms in soil change frequently
– Soil moisture level, organic fraction, temperature
– We usually don’t soil test for N levels
• Little attraction to clays and organic matter
• Primary uptake forms:
– Nitrate-Nitrogen NO3– Ammonium-Nitrogen NH4+
Nutrient Needs/Removal
• The greater the yield, the greater the fertilizer
need
• Nutrients must be replaced to sustain yield
– Synthetic and/or organic fertilizers
Nutrient Replacement for Hay
Fertilizer costs based on removal for cool-season
grass hay
Nutrient
Nutrient
($/lb)
Removal
Rate (lb/ton)
Value per
Ton
Value per
Acre (3 ton)
0.71
45
31.95
95.85
Phosphate
(DAP)
0.54
12
6.48
19.44
Potash
0.55
50
27.50
82.50
Nutrient
Ammonium
Nitrate
Fertilizer
Total nutrient value: $62.59/ton of hay harvested
Legumes
• ~ 80% of atmosphere is N-gas (N2)
– Remember the uptake forms
• Nodules are home to nitrogen-fixing bacteria
– Bacteria convert N2 to NH3
• Most fixed N goes to host plant
• They will save you $$$$$$
– Dilution and lessening of fescue endophyte
Nodulated Plants Produce Nitrogen
• Seeds should be inoculated to ensure fixation
– Rhizobium bacteria
– Presence in soil
Not inoculated
Inoculated
Legumes
Dry matter yields of tall fescue-red clover vs tall fescue
with N fertilizer (Lexington, KY, 2-yr average)
Treatments
Tall fescue-red clover
6 lb seed/A
Tall fescue + nitrogen
0 lb N/A
90 lb N/A
180 lb N/A
Adapted from Southern Forages
Yield, lb/A
11,100
3900
6700
9900
Legumes
Adapted from Utah State University
• Yield response
without legumes:
– Price of N
application is not
worth the minimal
yield response
• 20 to 30% legumes
provide sufficient
N for grasses
Nitrogen Fertilization of
Grass/Legume Mixes
35
% Lespedeza
30
25
20
15
10
5
0
0
25
50
Nitrogen lb/acre
100
Nitrogen Fixation by Legumes
Legume
Alfalfa
Red Clover
Ladino Clover
Annual Lespedeza
N Fixed (lb/A/yr)
150-250
75-200
75-150
50-150
Adapted from Southern Forages
• At $0.71/lb for ammonium nitrate:
– Legumes fix between $35 and $177 of N/ac/yr
Nutrient Replacement
Fertilizer costs based on removal for cool-season
grass/clover mixed hay
Nutrient
Ammonium
Nitrate
Phosphate
(DAP)
Potash
($/lb)
Removal
Rate (lb/ton)
Nutrient
Value per
Ton
Nutrient
Value per
Acre (3 ton)
0.71
45
31.95
95.85
0.54
12
6.48
19.44
0.55
50
27.50
82.50
Fertilizer
Total costs: $31.95/ton with legumes as the N source
Evening Out Nutrient Distribution
• Consider how & where you feed hay...
– Unrolling, stationary bale rings, move bale rings
• Dragging
Hay Feeding Impacts Nutrient
Cycling
Forage Systems Research Center Study – Linneus, MO
Investigators: John Lory, Dave Davis, Rob Kallenbach, Justin Sexton
• 3 Treatments; 3 Replications
– Stationary Hay Rings
– Moved Hay Rings
– Bales Unrolled Around Pasture
• 13 cows per treatment with one collared
• 15 fescue bales fed to 13 cows in 42 days
• 1st Year – Last Winter – No data yet
Treatment 1
Treatment 2
40’ X 40’
Hay Ring in
Set Feeding Area
Move Hay Ring
Every Other Day
Treatment 3
20’ X 40’
Unroll Hay in a
New Spot Daily
Stationary Ring
Moving Ring
Unrolling Hay
Move Hay Feeding Sites Often
• Regularly move feeders and feeding areas
• Do not use the same pasture for supplemental feeding
every year
– Use the hay field
Unrolling Hay
• Allows “boss” cows and timid cows to eat together
• Less hoof damage to feeding area because it is larger
• Distributes fertilizer nutrients back on field
Manures
• The good:
– Adds organic matter
• Helps improve many aspects of soil health
– Adds micronutrients
– Current price = $24 to $35/ton dumped
• The bad:
–
–
–
–
The smell
Transportation costs
Availability
Nutrient variability
Nutrient Concentration of Manures
Source
Poultry Litter
Beef Feedlot
Dairy Slurry
Pig Slurry
Pig Effluent
Units
lbs/ton
lbs/ton
lbs/1000 gal
lbs/1000 gal
lbs/acre-in
Research adapted from Dr. John Lory, University of Missouri
N
69
24
25
58
135
P 2O 5
82
23
25
40
102
K2O
37
30
40
24
192
N, P, and K in Poultry Litter
20 to 60% of N can be lost when surface applied
Plants take up phosphate (P2O5),
not phosphorus (P) - 80% Available Yr. 1 (100% by Yr.2)
P X 2.27 = P2O5
Plants take up potash (K2O),
not potassium (K) - 100% Available Yr. 1
K X 1.2 = K2O
Fertilizer Value
Formula:
lbs/ton X availability X price/lb = fertilizer value
Nitrogen
55 X 0.6 X 0.71 = $23.43/ton
Phosphate (DAP) 78 X 1.0 X 0.54 = $42.12/ton
Potash
55 X 1.0 X 0.55 = $30.25/ton
Total value = $95.80/ton
Meeting the Removal Need?
• Scenario:
– 3 ton hay/acre harvested
– Nutrients removed:
• N = 135 lb/ac (45 lb/ton)
• P2O5 = 36 lb/ac (12 lb/ton)
• K2O = 150 lb/ac (50 lb/ton)
– 2 ton litter/acre applied
• N = 33 lb avail./ton x 2 ton = 66 lb/ac (55lb – 40% loss)
• P2O5 = 78 lb/ton x 2 ton = 156 lb/ac
• K2O = 55 lb/ton x 2 ton = 110 lb/ac
A CD/A is a pasture yield goal that means "cow day per acre." This is enough forage dry
matter for a 1,000-pound cow with a calf less than 4 months old for one day. In Missouri
this is considered to be 30 pounds of forage dry matter per day. For example, a yield
goal of 200 CD/A is roughly equivalent to 3 tons of forage dry matter per acre.
Yield Response Curve
Apply
Maintenance
Fertilizer
100%
95%
Apply Buildup +
Maintenance
Fertilizer
Detrimental
Maximum
Yield
Economic
Optimum
Yield
% Yield
Apply No
Fertilizer
50%
VL
L
M
H
VH
Soil Test Level
EX
Liming
“The poor man’s fertilizer”
• For cool-season grass:
– 5.5 to 7.0
• For legumes:
– 6.0 to 7.5
• Limit application to 2 to 3 ton/acre/year
• Applying 2 ton/ac every now and then is NOT
a good practice
Soil pH
• pH scale = 0 to 14
0=Strong Acid
7= Neutral
14= Strong Base
• For best plant
growth and
nutrient
availability:
pH= 6.2 to 6.5
Application Timing
• P, K, and lime take time
to work into the root
zone
• N doesn’t stick around
• Are there legumes
present?
• How low are your
current levels?
• Availability and price
of fertilizer
Nitrogen Application Timing
For Hay
Forage Growth Rate
Perennial Ryegrass
Tall Fescue
Orchardgrass
Feb
Apr
Jun
Aug
Oct
Dec
Nitrogen Application Timing
For Pasture
Forage Growth Rate
Perennial Ryegrass
Tall Fescue
Orchardgrass
Feb
Apr
Jun
Aug
Oct
Dec
Quality Soil Sampling
• BE CONSISTENT
– Sample every 3 to 5 years
– Sample at the same time every year
– Depth
• Avoid sampling soon after applying
fertilizer, lime, compost or manure
–Best to wait 1 year (at least 4-6 months)
• Avoid sampling hot spots
Soil test P (Bray-I, lbs./acre)
Soil Core Variability
200
Mean: 44 STD: 48
180
160
140
120
100
80
60
40
20
0
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61
Core number
Increasing Accuracy by Dividing Fields
Based on Known Variability
Old manure piles
Feeding areas
Soil test P (Bray-I, lbs./acre)
200
180
Pasture
160
140
Overall Mean: 44, STD: 48
120
100
80
Pasture mean: 20, STD: 17
Feeding area mean: 114, STD: 52
60
40
20
0
4 8 11 14 19 22 25 28 31 36 40 45 48 51 54 57 60 63 3 16 38
Core number
Management History Can Influence a
Soil Test
Rowcrop field 3
p
H
p
H
Rowcrop field 2
Rowcrop field 1
Pasture
Limestone road
6
.
6
6
.
6
6
.
4
6
.
4
6
.
2
6
.
2
6
.
0
6
.
0
5
.
8
5
.
8
5
.
6
5
.
6
5
.
4
5
.
4
5
.
2
5
.
2
5
.
0
5
.
0
4
.
8
4
.
8
4
.
6
4
.
6
Consequences of Forgoing
Fertilizer
•
•
•
•
•
Reduced forage production
Reduced persistence of desirable species
Excessive weeds and brush
Reduced forage quality
Yield loss
Take Home Points:
• Nitrogen is not easily retained in the soil and
should be added just before times of greatest
need
• P and K levels can be built up in the soil
• Nutrients must be replaced
• Legumes can save you N fertilizer costs
– Weed control should be considered prior to
overseeding
Take Home Points:
• Where and how you feed hay makes a
difference
• Manures are a good source of fertilizer and
organic matter
– Be cautious of excessive P levels
– Nutrient levels vary with different sources
– Help improve overall soil heath
Questions?
Sarah Kenyon
Agronomy Specialist
Houston, MO
417-967-4545
KenyonS@missouri.edu