The inclusion of red clover in grass grown for silage helps by biologically fixing nitrogen thereby reducing the greenhouse gas emissions and costs associated with chemical fertiliser use.

Red Clover


Red clover is a leguminous plant with an upright growth habit and a strong deep root from which finer roots arise. Red clover is mainly suitable for silage though livestock can graze after the final silage cut and can last for over six years under good management. 

Why should I include red clover in my grassland?

At inclusion rates of 25% and above the following benefits can be achieved from red clover.

  • Grass-red clover can produce high yields (up to 16tDM/ha).
  • Clover maintains high-quality pasture under low fertiliser input and a well-established clover sward can reduce chemical nitrogen fertiliser demand by 150- 250kg/ha annually. 
  • Grass-red clover swards have a high protein content(16 to 20% crude protein).

The farmer discusses grass-red clover swards.

How do I include red clover in grass swards for silage?

  • Red clover grows well in moist but well-drained soils, with pH 6-6.5 and a P & K index 3.
  • Applying slurry or cutting silage in wet weather should be avoided to minimise damage to the plant crowns and soil compaction by machinery. 

The following video provides detailed information on the establishment of grass-red clover swards for silage.

Learn more about Red clover agronomy management

Economic and Environmental Benefits

Incorporating red clover in silage paddocks reduces the fertiliser demand by 150-250kg/ha per year. The Table below shows the potential annual savings and emission reductions when red clover is used with grass swards for silage.

Savings and reduction in emissions from red clover inclusion

Scenario 1
Grass only
Scenario 2
Grass-red clover(10% of the area)
Scenario 3
Grass-red clover(25% of the area)
Total silage area(ha) 161616
The average quantity of nitrogen fertiliser (kgs/ha) 220198165
Fertiliser savings (€) 5701426
Extra reseeding costs (€) -213-532
Net Savings/farm(€) 357894
Environmental Impact
Total Emissions (kgCO2-eq /kg FPCM)0.9600.956 0.948
Reduction in emissions (%)0.421.25
kgCO2-eq /kg FPCM is the carbon footprint per kilogram of Fat and Protein Corrected milk
The May 2023 average  fertiliser prices of   €520/t  for CAN and  €602/t  for Urea were used (
Net savings/ cost are the savings or cost per year for the farm


Research at Farm Zero C

Red clover and perennial ryegrass (PRG) swards have been planted on some of the silage ground to reduce chemical fertiliser usage. Management practices employed to increase life span include maintenance of optimum soil pH (6.5), slurry application management, and avoiding the use of heavy machinery in wet weather to reduce damage to the red clover. 

Other Research

Key findings from previous research in red clover include:

  • Dry matter intake for grass-red clover swards was 1.6 kg/d higher than for grass (Johnston et al., 2020).
  • The digestibility of grass-red clover swards was also higher than grass-only swards. 
  • Generally,  grass-red clover swards have a higher protein content and digestibility than grass-only swards (Conaghan & Clavin, n.d.).

Links to more research


Including red clover in silage paddocks as a climate mitigation strategy is important to meet the following climate targets and regulations.

European green deal 

Farm-to-fork strategy

The Nitrates and water directive

The nitrates derogation– For derogation farmers, all new grass reseeds on the grassland farm shall incorporate at least 1.5 kg/ha of naked clover seed or at least 2.5 kg/ha of pelleted clover.

The Ag Climatise Roadmap 2021The use of red clover for silage supports the following actions of the roadmap to climate-neutral agriculture.

  •  “Action 1: Reduce chemical nitrogen fertilizer use by 40% by 2030.”
  • “Action 4: Maximise production of grazed grass.”

Available support -There is upcoming support for red clover for example the red clover silage measure by the Department of Agriculture, Food and the Marine(DAFM) to make red clover seeds financially accessible to farmers.


Farmers can easily purchase red clover seeds from their local merchants or cooperatives.