Transcript CAFRE Development Service

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Soil is made up of 3 main mineral
components
Sand
Silt
Clay
Proportion of each determines soil type
12 different soil types/textures
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Sand is gritty and breaks up if rolled
into a ball
Silt is smooth, silky or floury
Clay is sticky when wet, shiny when
smeared and holds shape
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Valuable source often overlooked.
Amount of nutrients depends on soil type,
rainfall and previous management
How to find out what’s in soil?
− Soil sampling
− Soil analysis
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Nitrogen (N) – most
important for plant
growth
Phosphorus (P)
Potassium (K) – often
referred to as Potash
Others important are
Sulphur (S),
Magnesium (Mg) and
Calcium (Ca)
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Sample every 4-5 years
Ideally October – February
when at least 3 months
since application of slurry,
manure,
fertiliser or lime
Walk a “W” pattern through
field
25 cores per sample
Send to laboratory for
analysis
1.
pH
2.
Lime requirement
3.
Phosphorous index
4.
Potassium index
5.
Magnesium index
Soil Acidity
pH 5.0 (Very Strong
acidic)
pH 5.5 (Strongly
acidic)
pH 6.0 (medium
acidic)
N
P
K
53%
34%
52%
77%
48%
77%
89%
52%
100%
Liming increases the availability of soil nutrients.
Your fertiliser is more efficient if soil pH is at optimum level.
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Conditions the soil
 Improves the availability of Nitrogen,
Phosphorus, Potassium, Sulphur,
Calcium & Magnesium
 Encourages micro-organisms in soil
which help to release nitrogen from
organic matter
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 Increases
earthworm activity
 Improves
soil structure
 Grass
is more palatable to
livestock (tastier)
Index
0
1
2
3
>4
Description
Deficient
OK for extensive
Optimum for grazing
or silage.
High
Excessive
Index
Description
0
Deficient
1
Low
2-
Optimum for grazing or
silage.
2+
High
3 & above
Excessive
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31% of samples below index 2 for P
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44% of samples below index 2- for K
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64% of samples below 6.0 for pH
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Only 1% of NI fields are sampled
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Only 18% are optimum so
82%
are not!
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Valuable source of nutrients
Sample every 4 years
Use analysis to determine the amount
of nutrients in the soil
The higher the soil nutrient reserves
(Index), the lower the need for
additional nutrients
Getting the balance right!
Nutrients
In
Nutrients
Out
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Standard
recommendations
for Nitrogen
Depends on P
index
Depends on K
index
Was slurry spread?
kg/ha
units/acre
1st cut
120
96
2nd cut
100
80
3rd cut
80
64
*
Recommendations are the upper limit of N application
Index
Phosphorus
0
1
2
3
4
Units
required
80
56
32
16
0
1
Index
2- 2+
Potassium
0
Units
required
112* 88** 64
*48 units previous autumn
**24 units previous autumn
48
3
4
24
0
Index
Phosphorus
0
1
2
3
4
Units
required
20
20
20
0
0
Index
Potassium
0
1
2-
2+
3
4
Units
required
96
80
72
48
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Standard
recommendations
for Nitrogen
Depends on P
index
Depends on K
index
Was slurry spread?
2.2 billion gallon
Produced in NI each year
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When – 1st February – 15th October in suitable
weather & ground conditions
Aim to apply slurry & manure in the same conditions
and weather as when applying bagged fertiliser. Leave
3-4 days after applying slurry before applying bagged
fertiliser – N loss minimised .
 Where
– 10m from water course, 20m from
lakes, 50m spring, well or borehole & 250m
public water supply
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Nutrient content of slurry depends on number
of factors
1.
2.
3.
4.
What were animals fed (levels & type)
Dry Matter (DM) of the slurry
Application method
Timing of slurry application
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Dry matter of slurry is important!
4% DM slurry will only contain half nutrients
of 8% slurry
Watery slurry is lower value
Service available to get slurry tested for DM
and nutrient content
Livestock Type
N
P205
K20
6% dry matter
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11
30
6% dry matter
20
11
22
4% dry matter
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* Nitrogen is full content. Not all this is
available to the plant (depends on timing).
Inverted splashplate
Trailing shoe
+ 24% more grass
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Benefits of Alternative
Slurry Spreading Systems
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More even spread
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Give less grass contamination
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Slurry spreading up to 4 weeks after cutting
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Reduced runoff – trailing shoe compared to
splash plate
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Can spread within 3m of watercourse rather
than 10m
Every 1000 gallons of a typical beef slurry
contains;
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7 units (N) Nitrogen
11 units (P) Phosphorus
22 units (K) Potassium
3000 gallons per acre = 21 units N, 33P, 66K
Net worth of 3000 gallons slurry?
Approx £41
Getting the balance right!
Nutrients
In
Nutrients
Out
1.
Soil sample
2.
Determine crop requirements
3.
How many nutrients can be supplied by
organic manures?
4.
Which chemical fertiliser can supply the
remaining nutrients required?
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Soil sample this winter!
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Apply lime if necessary
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Use slurry efficiently (timing and method)
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Use on-line calculators before purchasing
fertiliser