Proven varieties key to success of multi-species swards

Sheep on plantain red clover and ryegrass
Sheep on plantain red clover and ryegrass

Multi-species leys combining nitrogen-fixing and nitrogen-lifting pasture plants can offer significant benefits to sheep farmers, particularly in low input systems.

This is the message from Helen Mathieu of forage experts Germinal at the NSA Sheep Event.

However, she urged use of the best proven varieties only in order to be sure of good and consistent results, with grasses and clovers selected from the current Recommended List being a good basis for reliability.

"The concept of combining plants in a sward with complementary characteristics is now quite well understood, with some of the benefits having been demonstrated in widespread European studies," she explained.

"Including nitrogen-fixing species such as clovers alongside ryegrasses, for example, has been shown to result in comparable or higher animal performance than is achieved from ryegrass-only swards with higher nitrogen fertiliser inputs.

"There is also evidence showing that plants with different – but complementary – root structures can lead to more effective use of soil nutrients, giving an overall advantage compared to monoculture swards.

"Using deep rooting species such as perennial chicory or plantain, for example, means nutrients are being taken up from a different part of the soil profile than is the case with shallower rooting ryegrasses.

"Having a range of different species will also mean multiple sources of protein, energy and minerals, presenting a more complete nutritional profile.

"These benefits can certainly translate into improved animal performance, and help reduce reliance on bought-in feeds and fertilisers, but the effects will be compromised if sub-standard varieties are used."

Ms. Mathieu said that wherever possible it is advisable for at least half the seeds mixture to be a high ranking perennial ryegrass, with all other components to be either selected from the latest Recommended List for Grass and Clover or to be from a known and reputable source.