How do you grow the best herbal leys? Farmers will have the answer

Lots of attention has been focused on diverse herbal leys as an alternative to more simple mix leys in recent years. Buying in feed and fertiliser creates a significant cost to dairy farms. So finding ways of growing high quality pasture that doesn’t require large amounts of fertiliser is key to business viability. What’s more, herbal leys provide diversity that can overcome drought, help wildlife and provide livestock with key minerals and medicinal benefits. The benefits are clear, but how can you grow them to their best potential? A group of farmers have got together to find out.

A group of farmers have got together to do their own research on the matter. They want to expand on the performance of herbal leys by finding the right grazing approach to optimise the speed of regrowth and longevity of species diversity of the leys. Additionally, considering the right mixtures of seeds that produce the most consistent performance for their soils. They are trialling different lengths of grazing time to identify the ideal residual length (after the cows have been let on) to achieve long-lasting diverse species composition and the best nutritional feed value.

What are Herbal leys?

Herbal leys are a complex seed mixture of grasses, legumes and herbs. The diverse range of plants bring benefits to forage nutrient value, livestock health and soil fertility. They can save farmers money by providing farm grown alternatives to fertiliser inputs and mineral feed supplements. There are 17 plants or more that can be grown in a herbal ley and each of them has specific qualities. These include drawing up nutrients from the ground with deep roots, fixing nitrogen and providing medicinal benefits for the animals that eat them.

Some of the plants and their qualities (drawn from a very handy species guide by Cotswold seeds):

  • Legumes such as sainfoin, birdsfoot trefoil and clover fix nitrogen in the soil and have a high protein content.
  • Herbs such as chicory and ribgrass (plantain) have long roots capable of penetrating to great depth, breaking through plough pans and leaving the soil aerated, aiding drainage and crop root development.
  • Grasses such as tall fescue have a developed root system meaning it is tolerant to drought, damp and frost.
  • Evidence suggests that sainfoin, birdsfoot and chicory are also natural wormers.

Meet the trialists

The field lab, which is sponsored by BBSRC, brings together a mix of seven dairy farmers from conventional and organic farms across the country. One of these trialists is Peter Cheek, farm manager of Godminster Dairy Farm in Somerset. The farm supplies milk to Bruton Dairy and Godminster Cheese from its 300 cows based over 1100 acres of grassland and cereal rotation. Peter has been involved in lots of innovative on-farm research including field labs investigating compost teas and is also currently investigating ways of tackling mastitis with minimal antibiotic use using highly targeted treatment and early intervention.

He told us “The idea of the herbal leys is to try and create a diverse population of plants for the cows to eat that will enable them to milk at their optimum and hopefully have some health benefits as well. The diverse population of plants gives variety to the cows and each plant brings something to the table.”

“What we’re trying to find out with this trial is what is the optimum way of establishing the ley is in the first place. And then how you manage that ley to get the maximum out of it. And hopefully they’ll be drought resistance so if we have another dry summer some of the plants in the ley will survive to keep some green stuff there for the cows to eat”.

How the trial works

All the farms will have selected at least one field to use as a trial site. In most cases this is a ley that has been newly established for the trial. The number of fields used to grow herbal ley mixes varies across the trialists. Some have just one field that is newly sown as part of the trial, but others already have a large proportion of the farm established with diverse mixes. 

When the grazing cycle moves around the farm and hits the identified location, the grazing area of the leys will then be divided in two. The cows will be left to graze one part of the area to what the farmer would personally consider an optimal length (A). On the other half, the cows will be removed early, spending between ½ and ¾ of the time of group (A) so that the residual remaining is greater than the considered “optimal” height (B).

Dates will be recorded when the cows enter and exit a trial location and from both parts of the grazing area (A & B). Farmers will then collect data from 2-3 randomly thrown quadrats – species composition will be recorded, based on % cover grasses, legumes and herbs. Additionally farmers will identify where possible presence of key indicator species such as Chicory, Ribgrass forage herb, Burnett, Yarrow, Trefoil and Clovers.

Selected samples will also be sent for nutrient analysis (protein and fibre content) and dry matter content. Raw height measurements using a plate meter will be taken.

What next for the trial

Peter says “If the research on herbal leys proves successful we’ll roll them across the whole farm. So that we will then grow herbal leys as the main stage for our grazing platform. The research is on 60 acres at the moment so this would mean expanding the herbal leys to 300 acres”.

“To be able to prove that the herbal ley is the ultimate grazing ley would be the mecca for me. Once we’ve established that herbal leys are in fact the correct way to go forward. We then need to find out what herbs and other plants to grow within those leys. And that will need more research.”

He is keen for this research to create methods of farming where everyone can benefit. “I would share everything I know. I have been farming now for over 40 years and I have been lucky that loads of people down the years have shared their experiences. So I look forward sharing any information that we glean from any of these trials across the world.”

The benefits of farmer-led research

Peter explains that “Farmer-led research is about taking great ideas from really good farmers and then bringing them back home to see if they work within the system you’ve got”.

“At one stage I was seriously thinking that compost teas would be the answer. But having gone there I wasn’t convinced. So it’s often not just learning about what to do, it’s also about learning what not to do.”

“The hardest thing about researching on farm is focus. Herbal leys is a classic, we’re looking at how to establish and how to manage them yet we also think there’s a health benefit but we’re not meant to be looking at that. So that can be a challenge but because you’re working with other farmers, you are constantly learning because everybody has ideas to contribute.”

Get involved in your own farmer-led research

To keep informed of how this field lab and others are progressing sign up and become a member of the Innovative Farmers network. Got your own idea for a field lab? Then contact the team to find out how to get involved.

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