Growers should delay drilling of multi-species herbal leys

Good seedbeds remain important as ever

Growers trying multi-species leys for the first time this spring are advised to use the most appropriate establishment method.

Agronomists report a significant uptake in multi-species leys driven by the Sustainable Farming Incentive. But inexperienced growers could struggle – and see establishment backfire, says Jim Juby, of Horizon Seeds.

“Establishing herbal and multi-species leys is fundamentally different from grassland reseeding and it is important that people appreciate this if they want to get the best out of them,” says Mr Juby.

“Herbal and multi-species leys are far less likely to respond well to a low soil temperature. a soil temperature of 6^oC recorded five days consecutively, which is usually achieved in mid to late April, is more than adequate for grass to grow away quickly.

Warmer soil

“This is, however, too cold for these more vulnerable and slower growing forage species with the herb and legumes in the ley requiring a warmer soil to establish well.

“The legumes contained in multispecies leys mixes are particularly susceptible and these  are a key element of the crops as they provide the protein content that makes them so beneficial to cows and livestock.

“If these do not grow away quickly when sown, they will simply be overwhelmed by grasses and potentially weeds, and their contribution will be negligible.

“It is far better to wait until May when soil temperatures have been 8-10^oC for five consecutive days than go earlier for the sake of it.”

Heavier soils that hold onto water are likely to be the most problematic, he points out. “You might be able to go earlier in lighter soils that are more free draining, but the recommendations regarding soil temperature remain.

“The last thing you want is weak, open leys that can simply not get going and quickly succumb to weed pressure and more vigorously growing plants in the mix.”

Spring tips

Sowing in late spring and into summer is far preferable than autumn drilling. “It takes multi-species leys six weeks to establish themselves and to grow away, so you are unlikely to get the right conditions if you drill after 1 September.

“Soil moisture can be a problem as the summer develops, but there is far less risk of this being an issue than there is of too cold a temperature and day length post Autumn.

“A good herbal ley will, however, be capable of surviving and succeeding in both drought and waterlogged conditions where pure grass leys may suffer.

“They have generally high nutrient value with second cut silage, in particular, capable of containing very high protein levels plus there are numerous animal health benefits associated with them too, including athelmintic properties of the species included in the leys.”

It’s a good idea to plan drilling around weed flushes, says Mr Juby. Every farm has its own unique weed growth pattern so making sowing arrangements around these is always a good idea.

“Generally speaking, herbal leys require a very fine seedbed. As the seed size is so small, it is important to have as fine a tilth as possible for good soil to seed contact.

“Good seedbed preparation will aid moisture retention with double rolling dramatically improving this as well as helping with the all-important seed to soil contact.

“Undersowing herbal and multispecies leys under Spring cereal crops for wholecrop can also be carried out successfully if you’re in a position to do this.”

Weed control

While establishment and time of sowing are key elements of weed control, post emergence treatment can be very tricky with multi species leys, he points out.

“Weeds can be controlled by grazing hard and spot spraying or using a weed wiper for taller weeds, but spot spraying needs to be done very carefully as many of the species are very susceptible to sprays and drift can cause a lot of damage.

“The best advice is to leave the ley for a minimum of 6-8 weeks before taking a light graze to encourage tillering. Topping and mowing can also be carried out to control weed flushes.

“The ley will vary in make-up as the season evolves and strict grazing control and management is key in maintaining the quality as well as allowing for a good recovery.”