The document provides guidance on soil fertility management for 2022. It recommends applying slurry and fertilizer based on soil test results and grass growth to maximize nutrient use efficiency while minimizing costs. Specifically, it advises applying smaller amounts of slurry or manure in February as grass growth increases, and supplementing with fertilizer as needed to meet grass demands through March. The overall goal is to build soil fertility through balanced nutrient applications for increased grass production, profitability, and environmental sustainability.

1. Successful soil fertility management in 2022
- good for your pocket and the environment
David P. Wall
Teagasc, Johnstown Castle,
Co Wexford, Ireland
20th January 2022
IFA Webinar

2. Planning fertiliser decisions for the year ahead
Soil Fertility on Irish farms
139,525 soil samples analysed during 2018-2021
CAN(27%N)
€675/tonne
€2.50/kg N
UREA(46%N)
€950/tonne
€2.06/kg N
Protected
Urea(46%N)
€1000/tonne
€2.17/kg N
Phosphorus
€3.69/kg P
Potassium
€1.33/kg K
Ground Limestone
€22-24/tonne
pH <5.9 pH 5.9-6.2 pH 6.3-7.0 pH >7.0
Index 1 Index 2 Index 3
Index 4
3 2 1
Data Source: Plunkett, M., Murphy, P., Wall D.P. Teagasc

3. Wall D.P. Johnstown Castle, January 2022
3
National soil pH trends
.
Target soil pH?
Currently 55%
soils are within
target pH
range
Proportion of soil with optimum pH levels
(low acidity)

4. Crop response to increasing soil pH
Based on €181/t DM for Grass &
Grass-Clover Swards and €235/t S. Barley
Data adapted from ADAS and Teagasc research
Wall, D.P., Teagasc

5. 5
Why Build Soil Fertility?
• Increased grass production
• Increased sward persistence
post reseeding (ryegrass/clover).
• Increased N fertiliser efficiency
• Increased environmental
sustainability.
• Increased long-term profitability.
Wall D.P. Johnstown Castle, December, 2021

6. 6
% recovery of
total N inputs
by grass swards
Measured in grassland fields
(n=446) over 2 years on 21 dairy
farms in Ireland
Good Soil Fertility drives Nitrogen recovery
100
80
60
40
20
0
Wall et al, 2020, (Teagasc)
Efficiency
of
Nitrogen
recovery
by
grass
swards
(%)
Improving Soil Fertility
>30%
Increase
Wall D.P. Johnstown Castle, December, 2021

7. Wall D.P. Johnstown Castle, January 2022
7
Good soil fertility drives grass growth
4-5
t/ha
DM
All produced using similar levels of N fertiliser!
(225 kg/ha N)
xxx X X
X X
X

8. Splash plate
Opportunities to replace fertiliser
with organic manures
9 - 5 - 32
50 kg
N-P-K
19 - 7- 20
50 kg
N-P-K
Cattle Slurry
6%DM
Pig Slurry
4%DM
3 - 2- 12
50 kg
N-P-K
F.Y.M. Broiler Litter S.M.C.
28-12-36
50 kg
N-P-K
3 - 3 - 16
50 kg
N-P-K
€ 39 € 48
€ 20
€ 77
€ 15
Data Source: Wall, D.P & Plunkett, M., Teagasc Green Book Organic Manure nutrient values (€) based on fertiliser nutrient prices January 2022

9. 9
Spring Fertiliser Recommendations
for grassland farms?
Wall D.P. Johnstown Castle, January 2022

10. January
February
10
. . . .
≤2000 gals
20 kg/ha N
(16 units/ac N)
February: Low grass covers (<1000 kg DM/ha)
1st Round: Maximising the benefits of slurry
1000 gallons Cattle Slurry 6%DM using LESS =
Smaller application rates required early in the season!
Wall D.P. Johnstown Castle, January 2022
Cattle Slurry
or
Other manure
source

11. February
11
. . . .
≤2000 gals
20 kg/ha N
(16 units/ac N)
Early February: Low grass covers (<1000 kg DM/ha)
≤2000 gals
20 kg/ha N
(16 units/ac N)
Mid February
after grazing
.
Apply slurry following the first areas grazed
Wall D.P. Johnstown Castle, January 2022
1st Round: Maximising the benefits of slurry
Cattle Slurry
or
Other manure
source

12. Wall D.P. Johnstown Castle, January 2022
12
. . . .
≤2000 gals
20 kg/ha N
(16 units/ac N)
Early February: Low grass covers (<1000 kg DM/ha)
≤2000 gals
20 kg/ha N
(16 units/ac N)
Mid February
after grazing
.
End February
after grazing
.
≤2500 gals
25 kg/ha N
(20 units/ac N)
Keep sufficient slurry for application on your silage ground @ 3000 gal’s/ac
Apply more slurry as more fields are grazed
February
1st Round: Maximising the benefits of slurry
Cattle Slurry
or
Other manure
source

13. February
Wall D.P. Johnstown Castle, January 2022
13
. . . .
≤2000 gals
20 kg/ha N
(16 units/ac N)
Early February: Low grass covers (<1000 kg DM/ha)
≤2000 gals
20 kg/ha N
(16 units/ac N)
Mid February
after grazing
.
End February
after grazing
.
≤2500 gals
25 kg/ha N
(20 units/ac N)
Complete 1st round of nutrient applications
N fertiliser
29 kg/ha N
(23 units/ac N)
Apply N fertiliser to the remaining 30% area in Mid-February
if soil conditions are suitable
Mid February before
grazing
Cattle Slurry
or
Other manure
source

14. Wall D.P. Johnstown Castle, January 2022
14
N fertiliser
35 kg/ha N
(28 units/ac N)
N fertiliser
50 kg/ha N
(40 units/ac N)
N fertiliser
50 kg/ha N
(40 units/ac N)
March: 2st round of nutrient applications
N fertiliser
50 kg/ha N
(40 units/ac N)
Last area grazed: N fertiliser - 35 kg/ha N
(28 units/ac N)
N fertiliser
50 kg/ha N
(40 units/ac N)
N fertiliser
50 kg/ha N
(40 units/ac N)
N fertiliser (Compound?)
50 kg/ha N
(40 units/ac N)
Strong grass growth from early March onwards
Apply fertiliser N to meet grass growth demand.
Consider N-P-K compound where no slurry has been applied to deliver P & K
March
N
Fertiliser
or
N-P-K
Compound

15. Wall D.P. Johnstown Castle, October 2019
15
 Your soils are your most valuable asset – manage them well!
 Use soil test results to make soil fertility management decisions.
 Apply lime as recommended to neutralise soil acidity.
 In early spring match nutrient inputs to grass growth potential on a
field by field basis
 Target organic manures to fields with the highest P & K
requirement to maximise its fertilizer replacement value.
 Consider protected urea as your N fertilizer source