1. Soil & Nutrient Management

2. Soil Science

3. Soil Science Soil is made up of 3 main mineral components Sand Silt
Clay
Proportion of each determines soil type
12 different soil types/textures

4. Soil Science 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
Handout soil texture chart at this stage

5. Soil Science Handout soil texture chart at this stage
12 different soil types

6. Soil Science Soil sampling Soil analysis
Valuable source often overlooked.
Amount of nutrients depends on soil type, rainfall and previous management
How to find out what’s in soil?
Soils
Valuable source.
Soils contain a valuable natural source of nutrients, which is often overlooked. The amount will depend on the type of soil, and past management practices.
Soil type – sandy/peaty soils will tend to have lower nutrient reserves than clay soils.
Previous crop – different crops need varying amounts of nutrients for growth and will therefore remove nutrients from the soil in different amounts. For example silage has a high requirement for potassium and will therefore remove a lot of potassium from the soil.
Clover - the clover plant has the ability to fix nitrogen from the air. A grass sward with a high percentage of clover will have a lower requirement for chemical nitrogen.
Application of nutrients – supplying nutrients in whatever form will have an impact on soil nutrient reserves, depending on the amount supplied and what is utilised by the crop.
2. Pose the question – How do you find out what’s in the soil? – Click for answer
Soil sampling and soil analysis. Analysis is the method of assessing soil nutrient reserves. It measures the amount of plant-available nutrients in the soil.
Soil sampling
Soil analysis

7. Major nutrients in soil
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)
These are also the nutrient required by grass and crops for growth.
Nitrogen: the most important nutrient in farming and is required in the greatest amounts for grass production and for most crops. Without it plants would not flourish at all. It is taken up by the plants as ammonium and nitrate, NO3. The fertiliser industry and clover convert nitrogen from the air into forms available for plant growth.
Phosphorus: does not occur by itself in nature and is always combined with other elements to form phosphates, P2O5. It is taken up by the plants as phosphates. Phosphorus is extremely important for rooting, seedling development, cell division, and the synthesis of various compounds used by plants. Phosphorus is available to grass as H 2 PO 4 - and HPO 4 = and is mobile in plants (meaning that it can move from one portion of the plant to another).
Phosphorus deficiencies in turf are usually expressed in the early stages of seedling development, appearing as a purple or red coloring of leaf blades and as reduced growth and tillering.
Potassium: is also referred to as potash. Potassium’s primary role involves regulating several important physiological processes. Potassium activates plant enzymes used in protein, sugar, and starch synthesis. It also plays a key role in maintaining turgor pressure in plants. Thus, it has a strong influence on drought tolerance, cold hardiness, and disease resistance of grasses. Deficiencies of potassium may be expressed as increased susceptibility to drought, winter injury, and disease.
Sulphur is taken up by plants as sulphates.
Two other nutrients required in large quantities are magnesium and calcium.
6. All crops need a balanced diet these nutrients to grow efficiently. For example, applied nitrogen fertiliser cannot be effectively used by the plant when potash is deficient, and therefore expensive nitrogen fertiliser could be wasted.
7. Other nutrients required in much smaller quantities from the soil, e.g. Iron, zinc and copper. Micronutrients generally influence the health of the animal rather than grass growth rates.

8. Starting Point - Sample soils
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
Soil corers available from all DARD Direct offices
1 sample per 4ha (10 acres)
Small adjacent fields that have same management may be grouped together for sampling (up to 10 acres)
Larger fields should be subdivided
Handout as per DARD Direct soil sampling ‘How to take a soil sample’
Cost £10.44 per sample (20p per acre per year)

9. Understanding a soil analysis
A copy of the soil analysis will be sent to you and your adviser.
Refer to soil analysis leaflet
Farm survey & field number – indicates the location of the sample as you described on your soil sample bag. This is why it is important to clearly label samples.
pH – is a measure of the soil acidity.
Soil texture – is the proportion of sand, silt and clay in the soil as mentioned earlier.
Lime requirement – is determined by the pH. It is given in tonnes per hectare and in brackets tonnes per acre for both grassland and arable crops.
Available nutrients - The last three columns list the available amounts of phosphorus (P), Potassium (K), and magnesium (Mg). These are expressed in two ways:
concentration - mg/litre, or as
an index (_), which can range from 0-5
Question - Going back to the nutrients we looked at the start what is missing from the report?
Nitrogen: levels are not determined using soil analysis as there is no reliable analytical technique for measurement. Soil nitrogen levels are normally estimated after considering past management such as:
Application of organic manures
Previous crop type (may want to expand the importance of previous crop and nitrogen)
Question – What other nutrient is missing form the report?
Sulphur: not included in a standard analysis, but can be tested for at an extra cost, £5. As with phosphorus and potash, the available amounts of magnesium and sulphur are expressed as either mg/litre, or as an index ranging from 0-4 and above. As the amount increases so does the index.
Give out copy of this soil analysis to each participant. Will be required for later calculation.

10. Soil Analysis pH Lime requirement Phosphorous index Potassium index
Magnesium index

11. Lime

12. Liming increases fertiliser performance - % available to plant
Soil Acidity N P K
pH 5.0 (Very Strong acidic)
53%
34%
52%
pH 5.5 (Strongly acidic)
77%
48%
pH 6.0 (medium acidic)
89%
100%
Liming increases the availability of soil nutrients.
Your fertiliser is more efficient if soil pH is at optimum level.

13. What does lime do? 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
Lime is a soil conditioner. It corrects the soil acidity (raises the pH) enabling micro-organisms to thrive, break down plant and animal material and free nutrients for plant growth. Earthworm activity increases, which improves the soil structure and it assists the survival of clover bacteria.
Lime improves the availability of many nutrients, including nitrogen, phosphorous, potassium, sulphur, calcium and magnesium. 
The liming requirement is for year 1, not an annual application.
Where lime requirement is high (above 71/2 t/ha), a split application should be used. Apply at least half in year 1 and the remainder in year 3 or 4.
Lime breaks down the tough sod of old pastures on very heavy wet soils giving rise to a greater risk of poaching. The ‘little & often’ approach to liming should be used in such cases.

14. What does lime do? Increases earthworm activity
Improves soil structure
Grass is more palatable to livestock (tastier)
Lime is a soil conditioner. It corrects the soil acidity (raises the pH) enabling micro-organisms to thrive, break down plant and animal material and free nutrients for plant growth. Earthworm activity increases, which improves the soil structure and it assists the survival of clover bacteria.
Lime improves the availability of many nutrients, including nitrogen, phosphorous, potassium, sulphur, calcium and magnesium. 
The liming requirement is for year 1, not an annual application.
Where lime requirement is high (above 71/2 t/ha), a split application should be used. Apply at least half in year 1 and the remainder in year 3 or 4.
Lime breaks down the tough sod of old pastures on very heavy wet soils giving rise to a greater risk of poaching. The ‘little & often’ approach to liming should be used in such cases.

15. Understanding a soil analysis
Highlighted column is most important for Lime

16. Understanding a soil analysis
Highlighted column details P indexes

17. Phosphorous Index Index Description Deficient 1 OK for extensive 2
Deficient 1
OK for extensive 2
Optimum for grazing or silage. 3
High
>4
Excessive
Phosphorus is extremely important for rooting, seedling development, cell division, and the synthesis of various compounds used by plants. Phosphorus is available to grass as H 2 PO 4 - and HPO 4 = and is mobile in plants (meaning that it can move from one portion of the plant to another).
Phosphorus deficiencies in turf are usually expressed in the early stages of seedling development, appearing as a purple or red coloring of leaf blades and as reduced growth and tillering.
Phosphorus Index
Each Index relates to a range of phosphorus levels found in a sample e.g. Index 0 is the equivalent of 0-9mg/litre of phosphorus in the sample and means that the field or fields from which the sample was taken is deficient in phosphorus.
As the amount of phosphorus in the soil increases , so does the index. At Index 1 & 2 phosphorus levels are either adequate or optimum for growth, depending on the crop type. At Index 3 & 4 and above phosphorus levels are higher than what is required by the crop for growth.
How this information can be used to manage nutrients on the farm will be examined later.

18. Understanding a soil analysis
Highlighted column shows K indexes

19. Potassium Index (K) Index Description Deficient 1 Low 2-
Deficient 1
Low 2-
Optimum for grazing or silage. 2+
High
3 & above
Excessive
Potassium’s primary role involves regulating several important physiological processes. Potassium activates plant enzymes used in protein, sugar, and starch synthesis. It also plays a key role in maintaining turgor pressure in plants. Thus, it has a strong influence on drought tolerance, cold hardiness, and disease resistance of grasses. Deficiencies of potassium may be expressed as increased susceptibility to drought, winter injury, and disease.
Refer to soil analysis leaflet.
Potassium (potash) Index
Again each index relates to a range of potash levels found in a sample.
As with phosphorus, Index 0 is the equivalent to an available amount of potash, 0-60mg/litre in the sample and means that the field or fields from which the sample was taken are deficient in potash.
Question – do you notice any thing different between the indicies for potash compared to phosphorus?
Because of the wide range of Index 2 is split into 2- and 2+ and so will give a more accurate indication of levels in the soil. 2- is not the same as minus 2.
Again, as the amount of potash in the soil increases , so does the index. At Index 1, 2- & 2+ potash levels are either adequate or optimum for growth, depending on the crop type. At Index 3 & 4 and above potash levels are higher than what is required by the crop for growth.
Question – What index do you think the majority of soils in NI lie within?
Almost 60% of farmland (excluding mountainous areas) has soil K indicies of 1 or This is a consequence of the inadequate usage of potash fertiliser and slurry, particularly on cutting ground.

20. Averages for NI 2008-2103 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 1% of NI fields are sampled
Only 18% are optimum so 82% are not!
Optimum is greater than 6.0 for pH, P greater than or equal to 2, K greater than or equal to 2-

21. Soils - Review 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

22. Nutrient Management Planning
Getting the balance right!
Nutrients In
The sources of nutrients on the farm are soil, slurry /manure and fertiliser.
Nutrients found in soil and slurry/manure are already available on your farm and you should make use of these valuable on-farm nutrient supplies for growing grass and crops.
Fertiliser is an expensive chemically manufactured source of nutrients, which needs to be bought in.
There is no point in supplying chemical nutrients to crops or grass if they can be supplied by the soil and slurry/manures.
2. Nutrients out
Nutrients Out is the other side of the balance.
Crops such as grass & silage, cereals, potatoes, vegetables and horticulture, will remove only the nutrients they need for growth.
Nutrient management planning aims to balance the nutrients required by a crop for growth with those supplied to the crop. By taking account of the on-farm nutrients available in the soil reserves, slurry and manure, purchased fertilisers are only used to balance any outstanding crop needs. This ensures that nutrients are neither over supplied or under supplied and that the environment can be maintained, and productive crops grown.
Nutrients In
Nutrients Out

23. What fertiliser and how much will I sow?
Standard recommendations for Nitrogen
Depends on P index
Depends on K index
Was slurry spread?

24. Nitrogen requirements for silage*
kg/ha
units/acre
1st cut
120 96
2nd cut
100 80
3rd cut 64
Explain why both are stated
Explain that units per acre is more readily understood due to marketing of fertiliser and how we still speak of bags per acre
* Recommendations are the upper limit of N application

25. P + K for silage (1st cut) Index Phosphorus 1 2 3 4 Units required 801 2 3 4
Units required 80 56 32 16
Potassium 2- 2+
112*
88** 64 48 24
Potash – At index 1 apply 24 units per acre in previous Autumn and 64 units per acre in spring
Potash – At index 0 apply 48 units per acre in previous Autumn and 64 units per acre in spring
All recommendations taken from RB209
*48 units previous autumn
**24 units previous autumn

26. P + K for silage (2nd cut) Index Phosphorus 1 2 3 4 Units required 201 2 3 4
Units required 20
Potassium 2- 2+ 96 80 72 48 32
Handout page on P and K levels for different silage cuts, grazing and reseeds

27. What and how much fertiliser will I sow?
Standard recommendations for Nitrogen
Depends on P index
Depends on K index
Was slurry spread?
All sorted in NPK? But what about slurry?

28. Produced in NI each year
2.2 billion gallon
Produced in NI each year
Slurry nutrients
Each year 10 million m3 or 2.2 billion gallons of slurry are produced by housed livestock in Northern Ireland, 90% of which is cattle slurry.
Too often slurry and manure spreading is seen as waste disposal rather than a valuable source of nutrients. So this 10 million m3 should not be looked upon as a large volume of potentially polluting material, but also a large volume of potential NPK fertiliser.

29. Using slurry efficiently
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
When –closed period for FYM 31 October to 31 January
No closed period for dirty water
How much – 50t/ha (20/acre) FYM

30. Units in slurry
Nutrient content of slurry depends on number of factors
What were animals fed (levels & type)
Dry Matter (DM) of the slurry
Application method
Timing of slurry application

31. Units in 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
Cattle fed – bull beef slurry higher value than dry suckler cows due to intensive feeding
Pigs and poultry high
Dry matter – explain that no nutrients in water. Hence 5% DM slurry only half nutrient that of 10% DM slurry. Important to consider with umbilical systems

32. Total Nutrient Content of Slurry & Manure (units/1000gallons)22 18 36
4% dry matter 11 20
6% dry matter 30 27
K20
P205 N
Livestock Type
* Nitrogen is full content. Not all this is available to the plant (depends on timing).

33. What method? + 24% more grass Inverted splashplate Trailing shoe
The recent work by AFBI at Hillsborough has shown a yield increase of 24% in silage from using a trailing shoe type of spreader.
Inverted splashplate
Trailing shoe
+ 24% more grass

34. 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

35. Units in slurry 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
Fertiliser costs used to work out the value of slurry are:
27.5% N £235/tonne
£430/tonne
£315/tonne
Other Value of 3000 gallons of slurry applied in spring
Question- When is the right time to apply slurry and manure?

36. Nutrient Management Planning
Getting the balance right!
Nutrients In
The sources of nutrients on the farm are soil, slurry /manure and fertiliser.
Nutrients found in soil and slurry/manure are already available on your farm and you should make use of these valuable on-farm nutrient supplies for growing grass and crops.
Fertiliser is an expensive chemically manufactured source of nutrients, which needs to be bought in.
There is no point in supplying chemical nutrients to crops or grass if they can be supplied by the soil and slurry/manures.
2. Nutrients out
Nutrients Out is the other side of the balance.
Crops such as grass & silage, cereals, potatoes, vegetables and horticulture, will remove only the nutrients they need for growth.
Nutrient management planning aims to balance the nutrients required by a crop for growth with those supplied to the crop. By taking account of the on-farm nutrients available in the soil reserves, slurry and manure, purchased fertilisers are only used to balance any outstanding crop needs. This ensures that nutrients are neither over supplied or under supplied and that the environment can be maintained, and productive crops grown.
Nutrients In
Nutrients Out

37. How is it done? Soil sample Determine crop requirements
How many nutrients can be supplied by organic manures?
Which chemical fertiliser can supply the remaining nutrients required?
Nutrients on the farm can be balanced by:
Making effective use of soil analysis. Soil analysis is really the starting point for nutrient management planning.
Following the Codes of Good Agricultural Practice for the Prevention of Pollution of Water as discussed earlier.

38. Crop Nutrient Recommendation Calculator (www.dardni.gov.uk)

40. Summary Soil sample this winter! Apply lime if necessary
Use slurry efficiently (timing and method)
Use on-line calculators before purchasing fertiliser