1. Lime Advice for Grassland
Mark Plunkett, Teagasc, 2018
Lime Advice for Grassland
Mark Plunkett, Teagasc, Johnstown Castle

2. Presentation Notes
This presentation can be used for either drystock or dairy training groups as there is double slides for either group.
For example slides 4 & 5, 9 & 10, 13 & 14 are double slides and to be used for either a diary or drystock group during training

3. Annual Lime Applications
Mark Plunkett, Teagasc, 2018
Annual Lime Applications
Lime usage since Average lime usage between 1974 and 1984 was 1.7 million tonnes per year. Between 2000 to 2010 lime avaeraged ~700,000. In the last decade lime has averaged 860,000 tonnes of lime. Ireland should be at least applying in the region of 1.25 to 1.5 millions tonnes of lime per year to main soil acidity.

4. Soil pH for Grassland Soils
Mark Plunkett, Teagasc, 2018
Soil pH - Drystock
Soil pH for Grassland Soils
68% < pH 6.2
Lime is essential
Target pH 6.3
42,650 soil samples
68% of drystock soil needed lime in Target pH 6.3 on mineral soils

5. Soil pH for Grassland Soils
Mark Plunkett, Teagasc, 2018
Soil pH - Dairy
Soil pH for Grassland Soils
57% < pH 6.2
Lime is essential
Target pH 6.3
16,750 soil samples
In % of dairy soils tested at Teagasc required lime

6. Step 2 - Soil pH & Lime Advice
Mark Plunkett, Teagasc, 2018
Step 2 - Soil pH & Lime Advice
Step 2 in soil fertility management (5 steps) is correct of soil pH

7. Benefits of Liming pH 5.0 pH 6.3 Mark Plunkett, Teagasc, 2018
At low soil pH 5.0 grass and animal production is restricted due to the poor availability of especially N & P. Where soil pH 6.3 is maintained grass production will increase by ~1.0 to 1.5t DM/ha/year and grassland stocking rates and animal performance will be increased
pH 5.0
pH 6.3

8. How is lime lost from soils?
Mark Plunkett, Teagasc, 2018
How is lime lost from soils?
1 bullock
25 kg of Lime
1,000 L milk
3kg of lime
5 t/ha silage DM
75 kg of Lime
Offtake
100 kg = kg lime
N fertiliser
1 ha
Beef - Grassland Example
150 kg/ha N – 300 kg
2 bullocks – 50 kg
Lime loss in drainage – kg
Total lime required –
600 – 975 kg/ha/yr
1-2 ton/acre every 5 years
Shows major pathways for lime loss on a drystock farm – Rainfall largest pathway for loss followed by N usage while animal and crop off takes are small relative to others
Milk
mg / 100 ml
Ca = 122
1.22 mg of Ca (approx) per litre = 3 kg of lime / 1000 litres
17 kg from 5000 litres
Mean Ca from Herbage Survey data = 0.6% P = 6 kg per tonne of DM
5 ton crop = 30 kg of Ca = 30/0.4 = 75 kg of lime
Recycled in slurry
Grain = 0.6 kg per ton of grain – Low offtake
625 kg in drainage = 250 kg Ca
Only using 175 kg/ha/yr of Lime
Up to kg/ha/yr of lime in drainage
Lalor - Dairy Seminar, Limerick - 21 Jan 2014

9. How is lime lost from soils?
Mark Plunkett, Teagasc, 2018
How is lime lost from soils?
1 bullock
25 kg of Lime
1,000 L milk
3kg of lime
5 t/ha silage DM
75 kg of Lime
Offtake
100 kg = kg lime
N fertiliser
1 ha
Dairy - Grassland Example
250 kg/ha N – 500 kg
2 bullocks – 50 kg
15,000 L Milk – 45kg
Lime loss in drainage – kg
Total lime required –
845 – 1220 kg/ha/yr
1-2.5 ton/acre every 5 years
Shows major pathways for lime loss on a dairy farm – Rainfall largest pathway for loss followed by N usage while animal and crop off takes are small relative to others
Milk
mg / 100 ml
Ca = 122
1.22 mg of Ca (approx) per litre = 3 kg of lime / 1000 litres
17 kg from 5000 litres
Mean Ca from Herbage Survey data = 0.6% P = 6 kg per tonne of DM
5 ton crop = 30 kg of Ca = 30/0.4 = 75 kg of lime
Recycled in slurry
Grain = 0.6 kg per ton of grain – Low offtake
625 kg in drainage = 250 kg Ca
Only using 175 kg/ha/yr of Lime
Up to kg/ha/yr of lime in drainage
Lalor - Dairy Seminar, Limerick - 21 Jan 2014

10. Effect of soil pH on soil P availability
Mark Plunkett, Teagasc, 2018
Effect of soil pH on soil P availability
Soil P level (mg/L)
As soil pH increases soil P availability will also increase.
Soil pH
Data points represent the 35 fields on one farm (Doonbeg)

11. Why Lime Soils? Increases nutrient availability Soil N release
Mark Plunkett, Teagasc, 2018
Why Lime Soils?
Increases nutrient availability
Soil N release
80kgN/ha/year (2 bags CAN/ac)
Increases soil P availability
To move 1 P Index (€ /ha)
Lime before building soil P
Target pH
Increasing soil pH to the optimum will release up to 80kgN/ha/year which is worth ~€80/ha in N. Optimum soil pH will also increase soil P availability as per the graph. The soil pH in was the trial the soil pH 5.5, 5t/ha of ground limestone was applied. The graph shows increased soil P levels by 5.7 mg/l, 100kg/ha of P fertiliser increased soil P by 8 mg/l and lime and P increased soil P by 17.7mg/l. In conclusion correcting soil pH to the optimum pH 6.3 increases soil P availability.
Sheil et al, 2013

12. How Much Extra Grass Produced? Dairy
Mark Plunkett, Teagasc, 2018
How Much Extra Grass Produced? Dairy
€180
ROI €7:1
Improving soil pH from pH 5.2 to 6.4 increased grass dry matter production by 1.0t/ha DM. This is €180 /ton DM. 5t/ha of lime costing €125/ha is costing €25/ha/year. This represents a ROI of 7:1. Therefore for every €100 invested in lime gives an extra €700 worth of grass

13. Return on Investment from Lime
Mark Plunkett, Teagasc, 2018
Return on Investment from Lime
Farm example
Heavy clay mineral & peat soils
Soil pH from 5.5 to 6.3 over 5 years across the whole farm
Extra 1.0t DM/ha/yr (valued at €105 or
€180/ha)
Average 5.0 t/ha/yr (Costing €25/ha/year)
Return on investment of €4 -7 in extra grass for every €1 in lime
Shows return from investing in lime

14. Lime sources Ground Limestone Finely ground to react with soils
Mark Plunkett, Teagasc, 2018
Lime sources
Ground Limestone
Finely ground to react with soils
2. Magnesium Limestone
Higher neutralising value /slower to react / Use on Mg deficiency soils
3. Granulated Liming Products
Reacts very fast / Similar to Fertilisers / Seasonal soil pH regulation
Main source of lime is ground limestone – approximately 800,000 tonnes applied each year
Granulated lime – approximately 18 / 19,000 tonnes used annually

15. Mark Plunkett, Teagasc, 2018
Lime Standards
Statutory Regulations – Min Standards for Agricultural Lime
All producers are certified with DAFF
Total Neutralising Value (TNV >90%)
All product pass through 3.35mm sieve
Not less than 35% pass through a 150 µm sieve
Moisture content less than 3.0%
Lime standards
Each 1 tonne of ground limestone contains 350kg of fine / reactive material
~ 40 quarries licensed nationally

16. Ground Limestone Most effective Apply based on Soil Test
Mark Plunkett, Teagasc, 2018
Ground Limestone
Most effective
Apply based on Soil Test
Application rate based on soil pH
Most Cost effective
Speed of Actively
Quality
Fine lime work faster (35%) <0.15mm
Coarse lime work over time (65%) <3.35mm
Notes on ground limestone

17. Granulated Lime Products
Mark Plunkett, Teagasc, 2018
Granulated Lime Products
Finely ground limestone (<150 microns)
No. of Products on the market
6.5 times more expensive
Granular Product
100% plant available
Lower application rates
Fast acting to reduce soil acidity
Higher reactivity
Uses
Top Up where pH corrected
Lime Deficiency
Con-acre????
Notes on granulated lime

18. Liming Grassland – Rates
Mark Plunkett, Teagasc, 2018
Liming Grassland – Rates
Rates
Depends on soil pH
Depends on SMP pH
Max single App. 7.5t/ha
>7.5t/ha
Apply 50% now
Remainder in 2 years
Avoid high rates as they will:-
Reduce Major nutrients (esp. P)
Reduce minor nutrients (Mn, Cu, Zn & B)
Max. single application of 7.5t/ha
Greater than 7.5t/ha split the application for example 10t/ha – 50% now 50% in 2 years

19. Make best use of all windows of App.
Mark Plunkett, Teagasc, 2018
Make best use of all windows of App.
Grassland
Late autumn
Wash in over winter period
Early springtime
Low grass covers
After 1st / 2nd cut silage
Reseeding time apply during seedbed preparation
Wet soils / heavy equipment – Weather
Soil type / organic top – Clare
Little & often approach
Take every opportunity to apply lime

20. Managing lime on high Mo soils
Mark Plunkett, Teagasc, 2018
Managing lime on high Mo soils
Factors – Mo in herbage increased by:
Increased pH (>6.2)
Poor drainage (or wet weather)
Species: Clover > Yorkshire fog > Meadow grass > Fescue > Timothy
Low Nitrogen inputs
(Higher N  higher yields  Dilution of Mo in herbage + less clover)
High Mo Maps
Factors affecting availability of Mo

21. Managing lime on high Mo soils
Mark Plunkett, Teagasc, 2018
Managing lime on high Mo soils
Soil poor indicator of herbage Mo – Test Herbage (Spring & Autumn)
How high is high?
Mo in herbage > 2 mg/kg DM
High Mo advice is very crude
Indicator of some history in area
Over write as required - local knowledge & experience
5 t/ha reduction is crude
e.g. soil sample: pH = 5.7 & LR = 4t/ha
 reduce application but not eliminate?
Remember aim for pH 6.1/6.2 on these soils
On high Mo soils deduct 5t/ha and for aim for a pH 6.1 to 6.2
Where soils are limed to the optimum pH and lime is applied as recommended then treat animals where a Copper deficiency arises

22. In Summary Sample every 5 years Prepare farm lime plan
Mark Plunkett, Teagasc, 2018
In Summary
Sample every 5 years
Prepare farm lime plan
Ground limestone most effective
20% of farm annually
Spread costs / Finance / Budget
Reduce Mo problems if present (- 5t/ha)
Take all opportunities to apply lime
Maintain soil pH 6.3 – 6.5 on mineral and pH 5.5 on peaty soils
Summary