White clover has a huge role to play on Irish beef farms, according to Teagasc’s Dr. Michael Egan.

The research officer highlighted the benefits of incorporating white clover into grazing swards at last week’s Irish Grassland Association (IGA) Beef Conference.

Results from Egan’s PhD, based on white clover and carried out in Teagasc Moorepark, found:

  • An increase of 12% in grass production;
  • Potential to reduce chemical nitrogen applications;
  • Increased animal performance of 12-15% higher output.

Increases in animal performance of up to 15% were found particularly in the second half of the year, Egan explained.

However, this work was carried out under a dairy system and a current research project is currently looking at the benefits of including white clover under other livestock production systems.

Teagasc work has shown that white clover growth is very seasonal and its contribution to sward herbage mass varies across the year.

When included in grass swards, white clover can reportedly increase overall herbage production by between 1 and 1.5t DM/ha.

As the cost of chemical nitrogen fertiliser continues to increase, and with limited application rates under the Nitrates Directive, there is heightened interest in white clover and its ability to fix atmospheric nitrogen.

Previous research carried out by Teagasc has shown that clover can contribute up to 100kg of nitrogen/ha/year, through nitrogen fixation.

To incorporate clover into the sward, direct reseeding is a successful method. However, it will take a number of years to establish white clover over the entire grazing area.

A simple, low-cost method is recommended; by over-sowing the seed into existing grass swards.

“That will only work if you have good soil fertility and if you are going to manage your swards,” Egan stated.

Clover will establish and persist only on high-fertility soils. Rhizobia bacteria that fix atmospheric nitrogen are more productive in soils with a pH of greater than 6.3.

Clover is not going to fix a [soil fertility] issue that’s there. You need to solve the issue before you put in the clover.

“Clover can work, but it needs to be managed just as well as the perennial ryegrass in the grass sward,” Egan concluded.