Coping with high fertiliser prices on grassland farms

Fri, 17 Apr, 2026 - 14:55

Mark Plunkett

Rising fertiliser costs are forcing many grassland farmers to rethink how they manage nutrient inputs. The good news is there are practical, farm-level steps you can take to reduce purchased fertiliser needs, protect yields, margins, while improving environmental performance.

Why act now?

Fertiliser is a controllable input: small changes in practice can give big savings. Improved nutrient use efficiency reduces waste, greenhouse gas emissions and run-off risk. Taking on different practices helps reduce the global impacts which are outside our control.

Practical strategies

1. Start with a plan — Soil test results

Get up-to-date soil tests for pH, P and K across your farm. This will form the basis for nutrient applications. It will provide a solid foundation as to where best to apply different sources of available nutrients (manures and fertilisers). Where fertilisers have been purchased, use them wisely to maximise their utilisation. For example, apply maintenance rates of P and K and ensure adequate S applications to maximise utilisation of applied N.

2. Lime to the right pH

Correcting soil pH to target (~6.3-6.5 for rye grasses & 6.5-6.8 for clover/multispecies swards), this will ensure the best return on investment — it improves soil nutrient supply, fertiliser response, biological nitrogen fixation and persists for many years, reducing future fertiliser need.

3. Use organic nutrients efficiently

Make best use of slurry and farmyard manure – apply in springtime with a trailing-shoe/band spreader to reduce N losses, and spread on most suitable days. Measure slurry nutrient content where possible and adjust application rates based on slurry quality (N-P-K). For example, diluting cattle slurry increases N availability but reduces P & K content.

4. Alternative sources of organic fertilisers

Consider importing organic fertilisers such as pig slurry or cattle slurry where available. Pig slurry is a well-balanced fertiliser and is ideal for grazing ground, and can effectively replace the need for such fertilisers as 18-6-12 / 13-6-20 due to its similar nutrient profile. For example, 1,000 gals of good-quality pig slurry is equivalent to one 50kg bag of 19-7-20.

5. Shift to legumes and mixed swards

Introduce clover (red clover in leys, white clover in grazing swards) to supply biologically fixed N. Well-managed clover can replace a substantial share (+100kgN/ha) of purchased N fertiliser over a year, lowering costs, improving animal performance and profitability.

6. Target inputs to performance

Apply N when conditions are most favourable to maximise uptake and utilisation by grass.

For example, adjust fertiliser rates based on grass sward quality / seasonal demands. Favour high-performing paddocks (good soil fertility / reseeded in the lastfive years) and reduce on poorer fields.

Use PastureBase or farm records to match N to herbage demand and stocking rate.

7. Timing, placement and product choice

Split N applications to match grass growth and avoid heavy early-season single doses.

Apply fertilisers when the soil is warm and dry enough to reduce losses. Consider protected urea or urease/nitrification inhibitors to reduce costs and reduce total farm GHG emissions.

8. Improve slurry and fertiliser spreading efficiency

Set up the fertiliser spreader and calibrate to deliver the correct rate and even fertiliser application. Calibrate LESS slurry technology to ensure correct rates of application.

LESS technology reduces N loss and improves the precision of slurry while reducing chemical fertiliser N use. Liquid fertilisers (UAN/Acidified N) are more precise and efficient forms of nutrients, delivering productivity and environmental benefits.

9. Reseed and manage swards for efficiency

Carry out selective reseeding of poor-performing swards; a younger, grass clover/multispecies swards typically return more grass per unit of N input. Good grazing management (optimum pre- and post-grazing covers) increases utilisation of home-grown forage and reduces purchased feed.

10. Reduce feed and input demand through herd management

Match stocking rate to grass growth, while maximising the production of grass silage to ensure sufficient quantities of quality winter feed while reducing input of concentrate feeds.