2011 Southeast Hay Convention
Fine- Tuning Fertilization
in Your Hayfields
Annual Nutrient Removal by the
Primary Hay Crops in the South
Alfalfa Bermudagrass Orchardgrass Perennial Peanut Tall Fescue Nutrients Removed (lbs of Nutrient/Acre/Year) 300 250 200 150 100 50 0 Nitrogen Phosphate Potash Calcium Mag Adapted from Southern Forages, 2007 and Myer et al, 2010.
350
Spinner Spreader
Air-flow Applicator
50 lbs/A
100 lbs/A
Application Rate (lbs/acre)
300
200 lbs/A
300 lbs/A
250
200
150
100
50
0
-18.29
-13.72
-9.14
-4.57
0.00
4.57
9.14
Transverse Distance (m)
13.72
18.29
Spinner Spreader
Source: Fulton et al., 2003; 2005
800
100 lbs/A
200 lbs/A
300 lbs/A
400 lbs/A
Application Rate (lbs/acre)
700
600
Desired Levels
500
400
300
200
100
0
-10.7
-8.0
-5.3
-2.7
0.0
2.7
Spread Width (m)
5.3
8.0
10.7
Spinner
Spreader
Air-flow Applicator
Source: Fulton et al., 2003; 2005
Dr. Dennis Hancock
Extension Forage Specialist
Source: Fulton et al., 2003 and unpublished data
1
Air-flow
Applicator
2011 Southeast Hay Convention
Fine- Tuning Fertilization
in Your Hayfields
Fertilization Trick
Account for N Loss from Urea-based Products
High to Low
Source:
Fulton et al., 2003
Low to High
N Fertilizer Application
Urea
+ H20
Urea
urease
+ H20
Ammonia
urease
+
Ammonium
Urea
+ H20
Ammonia
The Effectiveness of Some Alternative N Sources at
Low, Medium, and High Fertilization Rates on Hybrid
Bermudagrasses (Relative to Ammonium Nitrate).
AN
34-0-0
urease
Nitrogen Source
+
Nitrate
Dr. Dennis Hancock
Extension Forage Specialist
250-350 lbs
100%
100%
100%
Amm. Sulfate
95-97%
95-105%
60-70%
Anhyd. Ammonia
UAN Solution
92-94%
93-95%
94-95%
80-85%
85-92%
92-95%
Urea
79-82%
82-92%
88-93%
Ammonium Nitrate
Ammonium
Fertilization Rates
< 200 lbs*
* Actual lbs of N per acre per year.
Source: Burton and Jackson, 1962; Silveria et al., 2007.
2
> 400 lbs
2011 Southeast Hay Convention
Fine- Tuning Fertilization
in Your Hayfields
Fertilization Strategies
New N Fertilizer Products
Alternative N Sources
Take-home message:
If you have to use a urea-based product, be careful
about cutting your rate back too much.
-  They are relatively less effective at low rates.
Introduction
Ammonia Volatilization Trap Data
2008-2009 (avg. over two locations)
Ammonia (NH4-­‐N) Vola=liza=on • Without AN, users of N
face risky alternatives.
  NH3 volatilization loss
• Urease is abundant in
thatch & organic layers
Urea
NBPT
  High N use in hay.
Polymer
Coating
• Enhanced Efficiency N
Fertilizer Products may
reduce volatilization loss
  Urease inhibition
  Encapsulate & release
100 80 60 40 20 0 maleic-itaconic
co-polymer
Urea Ammonia Volatilization Trap Data
NSN ESN 2008-2009 (Calhoun)
2009 2008 20,000 2009 120 100 (lbs/acre) Forage Yield (ppm) Ammonia (NH4-­‐N) Vola=liza=on 140 ATU Bermudagrass Hay Yield
2008-2009 (avg. over two locations)
2008 2009 120 (ppm) Ammonium Nitrate
2008 140 80 60 40 15,000 10,000 5,000 20 0 0 AN4 U4 AN2 U2 ATU SU NSN ESN CON Dr. Dennis Hancock
Extension Forage Specialist
Urea 3
ATU NSN ESN 2011 Southeast Hay Convention
Fine- Tuning Fertilization
in Your Hayfields
Bermudagrass Hay Yield
Results: Yield Data
2010 (Equal splits, 4 applications, 300 lbs N/ac total)
2008-09: Forage Yield of ‘Russell’ Bermudagrass
Source Equal Splits† 12,000 2008 2009 Eatonton Calhoun Eatonton Calhoun 19291 16033 16985 17302 18500 18218 10009 1552 11431 8163 10226 10730 8142 12106 2178 1059 17525 17019 16464 14955 15948 17604 10409 2460 (lbs/acre) 8908‡ 6430 8704 8490 7211 9641 2688 1204 Forage Yield 2 2 2 2 4 4 -­‐ 8,000 6,000 4,000 2,000 † Equal split applicaVons of N that occurred during the season. ‡
Eatonton 10,000 -­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐ (lbs of DM/acre) -­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐ ATU ESN NSN Urea Urea AN Check LSD0.05 Calhoun Total N applied = 300 lbs N/acre. Items that are in bold font are not significantly different
from the highest value in the column.
0 AN ATU Urea Another Fertilization Trick
Summary of EE N products
Agrotain Treated Urea
Split Your Potassium Applications!
as compared to urea applied in the same
way (averaged over 4 site-yrs):
•  Reduced ammonia volatilization by
over 63%.
•  Produced 11% more forage yield.
•  Recovered 19% more of the applied N.
•  Did not substantially affect crude
protein content.
•  Did not substantially affect the risk of
nitrate toxicity.
40-50%
in the Spring
K is the Key to a Good Stand
K is for Persistence
Not Competitive
Leafspot Diseases
Poor Winterhardiness
Grows Very Slow
Poor Stress Tolerance
The Stand is Gone!
Dr. Dennis Hancock
Extension Forage Specialist
50-60%
in mid – late season
4
2011 Southeast Hay Convention
Fine- Tuning Fertilization
in Your Hayfields
Aluminum Toxicity – Low Soil pH
Alfalfa
Low Soil pH
control
Effect of Gypsum (CaSO4)
on Root Growth - Alfalfa
treated
Tissue Sampling and
Troubleshooting
Source: Dr. M.E. Sumner
Tissue Sampling
Troubleshooting
6 in.
Dr. Dennis Hancock
Extension Forage Specialist
5
2011 Southeast Hay Convention
Fine- Tuning Fertilization
in Your Hayfields
Which is the better hay?
Chlorophyll and
Nutrient
Which is the better hay?
Foliar Fertilizer Applications
Mg
N
•  Even if the product is 100% efficient (likely isn’t)
H
•  The most a plant can take up across via the leaves is
the equivalent of 1-2 lbs/acre of the nutrient
  Works for many micro-nutrients (small quantities needed)
  Not feasible for macro-nutrients without multiple
applications. (large quantities needed)
C
O
www.georgiaforages.com
Dr. Dennis Hancock
Extension Forage Specialist
6