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Lime Advice for Grassland. Mark Plunkett, Teagasc, Johnstown Castle. Mark Plunkett, Teagasc. 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.
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Lime Advice for Grassland Mark Plunkett, Teagasc, Johnstown Castle Mark Plunkett, Teagasc
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 Mark Plunkett, Teagasc
Annual Lime Applications Mark Plunkett, Teagasc
Soil pH - Drystock Soil pH for Grassland Soils • 68% < pH 6.2 • Lime is essential • Target pH 6.3 • 42,650 soil samples Mark Plunkett, Teagasc
Soil pH - Dairy Soil pH for Grassland Soils • 57% < pH 6.2 • Lime is essential • Target pH 6.3 • 16,750 soil samples Mark Plunkett, Teagasc
Step 1. - Starting Point - Soil Analysis • Soil sample once every 3 to 5 years • Take samples every 2 to 4 ha • Sample to 10 cm • Take a min. of 20 soil cores • Leave 2 years between liming & soil sampling • Soil test most reliable for soil pH & LR advice • “Only apply lime based on a recent soil test report” Mark Plunkett, Teagasc
Step 2 - Soil pH & Lime Advice Mark Plunkett, Teagasc
Benefits of Liming pH 5.0 pH 6.3 Mark Plunkett, Teagasc
Nfertiliser 100 kg=180-220 kg lime 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 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 Up to 250-625 kg/ha/yr of lime in drainage Mark Plunkett, Teagasc
Nfertiliser 100 kg=180-220 kg lime 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 1 ha Dairy - Grassland Example 250 kg/ha N – 500 kg 5 bullocks – 75 kg Lime loss in drainage – 250-625 kg Total lime required – 825 – 1200 kg/ha/yr 1-2.5 ton/acre every 5 years Up to 250-625 kg/ha/yr of lime in drainage Mark Plunkett, Teagasc
Effect of soil pH on soil P availability Soil P level (mg/L) Soil pH Data points represent the 35 fields on one farm (Doonbeg) Mark Plunkett, Teagasc
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 Sheil et al, 2013 Mark Plunkett, Teagasc
How Much Extra Grass Produced? Drystock €105 ROI €4:1 Mark Plunkett, Teagasc
How Much Extra Grass Produced? Dairy €180 ROI €7:1 Mark Plunkett, Teagasc
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 Mark Plunkett, Teagasc
Lime sources • Ground Limestone (60% carbonate) • Finely ground to react with soils • Magnesium Limestone (40% MgCO3 60%CaC03 = 64.5% carbonate) • Higher neutralising value /slower to react / Use on Mg deficiency soils • Granulated Liming Products • Reacts very fast / Similar to Fertilisers / Seasonal soil pH regulation Mark Plunkett, Teagasc
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% Mark Plunkett, Teagasc
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 Mark Plunkett, Teagasc
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???? Mark Plunkett, Teagasc
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) Mark Plunkett, Teagasc
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 Mark Plunkett, Teagasc
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)
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 Mark Plunkett, Teagasc
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 Mark Plunkett, Teagasc