Welsh researchers are hopeful of breeding a disease-resistant variety of red clover which will extend the crop’s productive lifespan.
North Wales Daily Post reported “Aberystwyth University’s Institute of Biological, Environmental and Rural Sciences (IBERS) believes the new variety will improve protein production on farms across Wales.
If, after field trials, the clover is approved, IBERS expects it to lower farming reliance on expensive bought-in concentrates.
Research work is focused on improving the longevity of red clover, traditionally seen as its Achilles’ heel.
Historically, some producers have shied away from red clover due to a tendency for its yields to drop off after a couple of years.
Team leader Prof Leif Skøt said: “One of the biggest issues is that red clover is susceptible to trampling, and if the plants get damaged then they are susceptible to disease.”
The two main diseases are Stem Nematode and Crown Rot (Sclerotinia). By developing disease-resistant plants, IBERS aims to create a more robust, productive crop.
Several generations cross-breeding have been carried out and the team is now ready to combine resistance traits into a single population so it can be tested in the field.
“Stem Nematode and Sclerotinia are soil-borne pathogens for which we have no recognised chemical control,” said Paul Billings, of Germinal, one of the project partners.
“The current solution is to take a long gap in the rotation to minimise the potential risk.”
Unlike White clover, whose roots which spread across the soil surface, Red clover grows from a single crown. Once the crown is damaged, and becomes diseased, swards can quickly become gappy.
By improving its resistance, IBERS believes yields can be sustained well into the fourth and fifth harvests.
Even so, red clover pastures will still need to be managed to improve their longevity.
Swards should not be cut or grazed below 5cm to ensure the crown isn’t damaged.
“The crown of the plant is susceptible to damage, so we are looking at improving its structure,” said Prof Skøt, head of forage plant breeding at IBERS.
“Our research shows that if they have compact crowns then they are more resilient to damage from machinery and compaction from animals or grazing.”
With the correct management, red clover can give annual yields of 22-25 tonnes of dry matter per hectare when sown with grass. In the first year alone, dry matter contents can reach as high as 20 tonnes.
An organic farm in Ceredigion has been an advocate of red clover for over a decade – but it would embrace longer-lasting varieties.
The Cowcher family from Penrhiw, a Farming Connect focus site near Capel Dewi, has been using the crop since the holding went organic more than 10 years ago.
“It gives us high yields of good-quality forage, which can be difficult in organic systems,” said Phil Cowcher, who farms beef and sheep with his parents across 500 acres, part of which is share-farmed.
“It suppresses weeds because it’s very vigorous – if we get creeping thistles, it smothers and gets rid of them.
“Red clover is also important for fixing nitrogen. Cereals following red clover systems seem to yield very well, and as it has deep tap roots, it breaks up compaction.”
Red clover is grown on 45 acres for the farm’s beef and sheep enterprises.
Calves from a 60-head Stabiliser suckler herd tend to be fed the second and third cuts as part of the growing and finishing rations.
The first cut, which usually has a higher grass content and metabolisable energy, is usually fed to in-lamb ewes late in pregnancy.
Towards the end of the growing season, red clover leys are rotationally grazed by the farm’s Highlander lambs.
Phil said: “For the calves I like to feed two-thirds red clover with a third barley and peas for fibre.
“If it’s alone, it’s a bit rich, but by combining it with barley and peas it seems to complement the clover.
“We make sure lambs are introduced gradually to the red clover when they first graze it. Once they’ve adjusted, growth rates are good and they usually finish well – we start selling in June at around 19kg and the last ones go by October.”
Management is fairly simple, said Phil, but he stressed the importance of sowing in a fine seed bed when soils are over 10C.
In a cold spring, cereals are planted first. Once soil temperature is high enough, red clover ley is then sown into the growing crop with a grass harrow/air seeder.
“When we cut it we have to make sure we don’t cut it too low,” said the former Harper Adams student.
“We also have to be careful not to overgraze it and damage the crown.
“But for us red clover’s a high-quality, high yielding crop and we’ll definitely carrying on growing it” here.