Fertiliser and grass seed together account for most farms' second or third largest variable cost after feed. The right choices here — on variety, specification, timing, and volume — directly determine grass growth, silage quality, and the sustainability of your soil fertility over the long term. The regulatory environment around nitrogen application has also changed significantly in recent years, with the Nitrates Action Programme (NAP) now placing binding limits on most Irish farms. This guide covers everything from selecting a grass seed mix to buying fertiliser at the right time of year.
Grass Seed Mixes for Irish Conditions
Irish grassland management is built almost entirely around perennial ryegrass (Lolium perenne). Unlike most of continental Europe, Irish farms do not commonly grow tall fescue, cocksfoot, or timothy as primary sward species — the mild, wet climate favours ryegrass, which gives outstanding yields under rotational grazing and responds well to nitrogen.
When specifying a ryegrass-based seed mix, the key decisions are:
Diploid vs tetraploid: Diploid ryegrasses have two sets of chromosomes, smaller cells, higher dry matter content, and better persistence — they are the backbone of most Irish swards. Tetraploid varieties have four chromosome sets, larger cells, higher sugar content, and higher digestibility, but they are bulkier, have lower tiller density, and are less persistent under hard grazing. Most Irish seed mixes combine 70–80% diploid with 20–30% tetraploid to balance digestibility with persistence.
Heading date: Varieties are classified as early, intermediate, or late-heading. For spring-calving dairy systems, late-heading varieties are strongly preferred — they remain leafy and vegetative for longer, delaying the drop in digestibility that occurs when plants go to head. Heading date is the single most important selection criterion for intensive dairy systems. For beef systems or mixed enterprises, intermediate-heading varieties may give better flexibility.
Persistence: Irish grass sward replacement costs (reseeding) are significant — allow €300–450/acre all-in. You want sward persistence of at least 8–12 years, which requires varieties with proven persistence scores under Irish grazing conditions. The Pasture Profit Index (PPI) developed by Teagasc rates varieties on yield, quality, and persistence — always buy from the current positive PPI list.
Clover Inclusion for ACRES Compliance and Nitrogen Fixation
White clover (Trifolium repens) is increasingly central to Irish grassland management for two separate reasons. First, the ACRES agri-environment scheme (replacing GLAS from 2023) includes clover sward actions that require a minimum clover content in swards — farms enrolled in ACRES clover actions must demonstrate clover establishment and maintenance. Second, clover fixes atmospheric nitrogen at rates of 100–200 kg N/ha/year under good conditions, reducing bought-in fertiliser requirements and emissions.
Including clover in a reseed mix typically adds €15–25/acre to seed cost (clover seed is expensive). The recommended seeding rate for white clover is 2–4 kg/ha (0.8–1.6 kg/acre), included in the mix at sowing. Key management points: do not apply nitrogen to clover-rich swards during the growing season (it suppresses clover); graze swards down hard in autumn to reduce grass dominance; use a clover-safe herbicide if broadleaf weed control is needed.
Red clover (Trifolium pratense) is used in silage swards for its high protein content (up to 22% CP in fresh material). It's biennial/short-lived — typically needs reseeding every 3–5 years — but delivers outstanding silage quality and significant nitrogen fixation in cut swards.
Reseed Timing in Ireland
Irish reseeding windows are constrained by ground conditions and temperature. The two main windows are:
- Spring (April–May): Soil temperatures are rising, ground conditions are generally firm, and the reseed has the full growing season ahead. The main risk is competition from weed grasses and broad-leaved weeds. A spring reseed needs aggressive management — topping or grazing — to prevent new sward being shaded out.
- Late summer (August–early September): The preferred window for most Irish farmers. Weed competition is lower (annual weeds are past their main growth flush), soil temperatures are still high enough for good germination, and there is usually adequate moisture from autumn rainfall. The reseed establishes over autumn, overwinters, and is fully productive the following spring. The risk is drought in August — if conditions are dry, germination can be patchy.
Minimum soil temperature for ryegrass germination is 6°C; optimum is 14–18°C. Do not reseed into compacted, waterlogged, or puddled ground — good seedbed preparation (ploughing or minimum tillage, consolidation, fine tilth) is more important than seed variety selection.
Fertiliser Categories: CAN vs Protected Urea vs Straight Nitrogen
Calcium Ammonium Nitrate (CAN) at 27% N has been the standard straight nitrogen fertiliser on Irish farms for decades. It's reliable, fast-acting, and well-understood. Its limitation is that it emits ammonia (a regulated air pollutant) and, under some conditions, contributes to greenhouse gas emissions.
Protected urea (urea 46% N with a urease inhibitor, typically NBPT) has been strongly promoted by Teagasc and the Department of Agriculture since 2021 as the preferred replacement for CAN. The urease inhibitor slows conversion of urea to ammonia in the soil, dramatically reducing ammonia and nitrous oxide emissions. Protected urea at 46% N delivers 70% more nitrogen per bag than CAN at 27% N, and its price per kg of N delivered is typically lower than CAN despite a higher per-tonne price. From a regulatory perspective, DAFM is moving towards mandating or further incentivising protected urea use — the direction of travel is clear.
Compound fertilisers (NPK blends — e.g. 18:6:12, 10:10:20) combine nitrogen, phosphorus, and potassium in a single granule and are used where soil P and K indices need building or maintaining. Compound fertilisers cost significantly more per kg of N than straight nitrogen products — you're paying for the P and K. Only apply compound fertilisers where your soil index actually requires the additional nutrients (confirmed by soil analysis).
Phosphorus, Potassium, and the Nitrates Action Programme
The Nitrates Action Programme (NAP), implemented in Ireland under the European Communities (Good Agricultural Practice for Protection of Waters) Regulations, sets binding limits on the amount of organic and chemical nitrogen, phosphorus, and potassium that can be applied to farmland. Key compliance requirements from 2026:
- Soil sampling is mandatory every 4–5 years for farms above certain thresholds. P and K applications must be matched to soil index — you cannot apply straight P on an Index 3+ soil without justification.
- Nitrogen limits per hectare vary by farm system, soil type, and stocking rate. Dairy farms in Nitrates Derogation areas (stocking rates above 170 kg N/ha from livestock) face additional conditions and must maintain detailed nutrient management plans.
- Chemical nitrogen applications are banned between 15 September and 12 January on most soils; organic nitrogen spreading closed periods vary by region and soil type.
- A Nutrient Management Plan (NMP) is required for farms above DAFM's threshold. Farm advisers (Teagasc, private consultants) can prepare these. The NMP determines your permitted application rates and must be followed.
Fertiliser prices in Ireland track global energy and gas markets (nitrogen fertiliser is made from natural gas). Prices are typically lowest in the October–December period after the main Irish growing season has ended and global supply is at a seasonal high. Spring demand (February–April) drives prices up sharply — in recent years the spring/winter price differential has been 12–22% on straight nitrogen products. If you have storage (a covered, dry bay for granular fertiliser), buying your full spring allocation in November saves real money. Discuss a forward purchase with your co-op or merchant — most will hold product for delivery up to March at the committed price. Fertiliser is safe to store for 12 months if kept dry and off the ground.
2026 Indicative Fertiliser Price Ranges (Ireland)
| Product | 2026 Price Range (€/tonne) | Notes |
|---|---|---|
| Protected urea 46% N | €440–480 | Most cost-effective N per kg; strongly recommended |
| CAN 27% N | €360–400 | Lower per-tonne price, but lower N content — more bags required |
| 18:6:12 NPK compound | €480–540 | Only where soil index requires P and K addition |
| 10:10:20 compound | €460–510 | Autumn/silage K maintenance dressing |
| Lime (ground limestone) | €48–65/tonne spread | Most Irish soils are too acid; lime is the highest-return spend |
Grass Seed Prices 2026
Perennial ryegrass seed is sold by the kg and typically applied at 14–20 kg/ha (6–8 kg/acre) for a full reseed, or 6–10 kg/ha for overseeding. Quality certified seed (DAFM approved varieties) costs approximately €2.20–3.50/kg for diploid varieties and €3.00–4.20/kg for tetraploid. White clover adds €8–14/kg for seed. A full reseed mix (12kg/acre of ryegrass + 2kg/acre of clover) will cost approximately €30–55/acre in seed alone before establishment costs.
Suppliers for Seed and Fertiliser in Ireland
The main co-operative suppliers — Tirlán, Dairygold, and Fane Valley — all carry full ranges of grass seed mixes (including PPI-listed varieties), protected urea, CAN, and NPK compounds, and offer agronomic advice as part of their service to milk suppliers. For farms not tied to a co-op, FRS Network can aggregate buying power for both seed and fertiliser across multiple farms. Most of these suppliers offer soil sampling services and can link soil analysis to fertiliser and lime recommendations.