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To gain an understanding of the principles of soil science
To assess the nutrient content of soils through soil sampling & analysis
To understand the importance of lime To be aware of nutrient content of animal
manures To be aware of nutrient requirements and
the planning of nutrient management
3
Soil is made up of 3 main mineral components
1.Sand2.Silt3.Clay
Proportion of each determines soil type 12 different soil types/textures
4
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
5
6
7
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
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)
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. Phosphorus index
4. Potassium index
5. Magnesium index
13
Soil Acidity N P K
pH 5.0 (Very Strong acidic) 53% 34% 52%
pH 5.5 (Strongly acidic) 77% 48% 77%
pH 6.0 (medium acidic) 89% 52% 100%
Liming increases the availability of soil nutrients.
Your fertiliser is more efficient if soil pH is at optimum level.
1982 1992 1998 2002 2007 2012
Tonnes of lime spread (000s)
365 137 78 96 73 129
£/tDelivered approx
£12 £15 £17 £20 £22 £23
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
Increases earthworm activity
Improves soil structure
Grass is more palatable to livestock (tastier)
Total lime required =
Field area x lime requirement per acre
Exercise – If field 13 is 8 acres in size how much lime is required
=8 x 2.5 = 20 tonnes
Same product just made from finest lime
Fast acting
Can be applied with fertiliser sower
Must be used each year to improve soil pH over time
Typically 100kg/acre
Has its uses but not effective long term
Index Description
0 Deficient
1 OK for extensive
2 Optimum for grazing or silage.
3 High
>4 Excessive
Index Description
0 Deficient
1 Low
2- Optimum for grazing or silage.
2+ High
3 & above Excessive
24
31% of samples below index 2 for P
44% of samples below index 2- for K
64% of samples below 6.0 for pH
Only 18% are optimum
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
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
Index
Potassium 0 1 2- 2+ 3 4
Units required
112* 88** 64 48 24 0
*48 units previous Autumn**24 units previous Autumn
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 32 0
Standard recommendations for Nitrogen
Depends on P index
Depends on K index
Was slurry spread?
32
2.2 billion gallon
Produced in NI each year
33
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
Nutrient content of slurry depends on number of factors
1.What were cattle fed (levels & type)2.Dry Matter (DM) of the slurry3.Application method4.Timing of slurry application
Nutrient content of slurry depends on what level of concentrate feeding stock received
Meal contains high levels of P and K so this will come through in slurry
Dry suckler cows receiving no concentrate will produce low value slurry
Bull beef fed straw and high level of concentrate will produce high value slurry
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
221836 4% dry matter
221120 6% dry matter
301127 6% dry matter
K20P205NLivestock Type
* Nitrogen is full content. Not all this is available to the plant (depends on timing).
38
Inverted splashplate
Trailing shoe
AFBI Hillsborough Research Results:
Reduced ammonia losses
Better N utilisation
Produces higher grass yields - Trailing Shoe + 24%
- Band Spreading + 16%
Benefits of Alternative Slurry Spreading Systems
More even spread
Give less grass contamination
Slurry spreading up to 4 weeks after cutting
Reduced runoff – trailing shoe compared to splash plate
Can spread within 3m of watercourse rather than 10m
Benefits of Alternative Slurry Spreading Systems
Timing N P K
Available Total Total
Feb - Apr 7.2 11 22
May - July 4.5 11 22
Aug - Oct 3.6 11 22
Every 1000 gallons of a typical beef slurry contains;
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
44
1. Soil sample2. Estimate Nitrogen requirements3. What nutrients does the crop require?4. How many nutrients can be supplied by
organic manures?5. Which chemical fertiliser can supply the
remaining nutrients required
46
CAN (27-0-0) 34-0-0 (Superstart) 46-0-0 (Urea) 24-6-12 27-4-4 20-10-10 25-0-13 0-46-0 0-0-60
1st Cut silage P index 1 K index 1
2500 gallons beef slurry per acre
How much and what type fertiliser is required?
Index
Phosphorus 0 1 2 3 4
Units required
80 56 32 16 0
Index
Potassium 0 1 2- 2+ 3 4
Units required
112* 88** 64 48 24 0
*48 units previous Autumn**24 units previous Autumn
Nitrogen (N) Phosphorus (P)
Potassium (K)
Required – units per acre
96 52 88
Slurry supplies
17 27 55
Required from fertiliser
79 25 33
Most suitable fertiliser
24 6 12
3 ¼ bags supplies
78 20 39
1st Cut silage P index 2 K index 2-
3000 gallons beef slurry per acre
How much and what type fertiliser is required?
Nitrogen (N) Phosphorus (P)
Potassium (K)
Required – units per acre
96 32 64
Slurry supplies
21 33 66
Required from fertiliser
75 0 0
Most suitable fertiliser
27 0 0
2 ¾ bags supplies
74 0 0