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

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

Annual Lime Applications Mark Plunkett, Teagasc, 2018 Annual Lime Applications Lime usage since 1974. 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.

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 2016. Target pH 6.3 on mineral soils

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 2016 57% of dairy soils tested at Teagasc required lime

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

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

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 = 180-220 kg lime N fertiliser 1 ha Beef - Grassland Example 150 kg/ha N – 300 kg 2 bullocks – 50 kg Lime loss in drainage – 250-625 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 http://www.milk.co.uk/page.aspx?intPageID=194 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 250-625 kg/ha/yr of lime in drainage Lalor - Dairy Seminar, Limerick - 21 Jan 2014

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 = 180-220 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 – 250-625 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 http://www.milk.co.uk/page.aspx?intPageID=194 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 250-625 kg/ha/yr of lime in drainage Lalor - Dairy Seminar, Limerick - 21 Jan 2014

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)

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 (€300-400/ha) Lime before building soil P Target pH 6.3-6.5 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

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

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

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

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

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

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

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

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

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

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

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