Results from a five-year trial, carried out by scientists at Reading University, confirms that dry matter output from diversified swards will out-perform that achieved by a perennial ryegrass (PRG) leys – receiving 250kg of nitrogen (N) per annum – three years after all the swards were established.

Significantly, the diversified leys did not receive bagged nitrogen at any time.This was one of the key findings delivered to delegates participating in the recent European Institute of Innovation and Technology (EIT) ‘Focus on Farmers’ webinar series, hosted by AgriSearch.

Reading University’s Dr. David Humphreys also confirmed that cattle on a grazing trial performed as well on the herbal leys as they did on the PRG sward.

The research trial, entitled the ‘Diverse Forages Project’, is centred on a number of sites across the south of England. Four different sward types are being compared: one containing 17 different species of grass, clover and herbs, one containing 12 different forage species and another comprising six different forage types.

“The PRG sward was the control,” Dr. Humphreys continued.

“The work, which addressed a wide range of sward-related issues, was extremely complex in nature.

“Analysis of the results obtained will be carried out over the coming months, the aim of which is to identify which species’ mixes can deliver the best return to beef farmers in a grazing context.

“But it is already evident that the use of diverse leys has a key role to play in helping to deliver a sustainable future for livestock producers.”

Soil structure

Reading University soil scientist Professor Martin Lukac also addressed the event. He said that soil structure was a key driver of soil productivity.

“All our grassland soils have evolved from a forest environment over many thousands of years,” said Lukac.

“In the past, biomass falling from the forest canopy would have provided the energy required to allow the soil below to function correctly.

Within a pasture scenario, it is the forage plants that provide the energy to allow the soil function effectively while also generating the capacity for the soil to support agricultural output on a sustainable basis.

Lukac stressed the importance of understanding soil biology.

“Soil health is also inextricably linked to soil structure and productivity. We know that employing a mix of herbs and grasses will help to optimise sward output,” he said.

“The wide range of root depths, which this approach will deliver, ensures that soils can adapt to the changing climatic and other related conditions which so characterise the growing conditions in this part of the world.

“Research trials have also confirmed that certain forms of silvo pasture will act to improve soil health further still,” Lukac concluded.