Assessing the benefits of Herbal Leys

Herbal leys were originally strongly advocated by pioneering organic farmer, Frank Newman Turner, who famously described them as ‘fertiliser merchant, food manufacturer and vet all in one’.

However, until the last few years a diverse herbal ley was shunned in favour of rye grass and white clover. It is only recently that farmers across the country are embracing them again, partly because of a growing list of benefits and as a replacement for increasingly expensive fertilisers. Luppo, a former dairy farmer turned consultant and nutritionist, has been keenly interested in herbal leys for a long time. This interest eventually led to him organising a trial with the Tamar Valley Organic Group (+B) to unearth the mysteries of herbal leys and their nutritional benefit.


What is the trial hoping to achieve?

We’re looking at mineral levels in different herbs within a herbal ley, and the herbal leys we have chosen to study are; plantain, chicory, rye grass and different legumes amongst others. Ultimately, we want to look at whether diverse leys can help address mineral deficiencies like the low iodine levels we’ve been seeing in organic milk, or if they can prevent Milk Fever at calving.

Some herbal leys are incredibly deep rooting and resilient and that’s another reason why we want to analyse minerals. If deep rooted herbal leys are helping bring up minerals from deeper down in the soil profile, are they giving us a different mineral profile? Do the mineral profiles for herbal leys differ from farm to farm depending on soil types? And do the mineral levels change throughout the year?


Organic farmers are very keen to find out a ways of avoiding mineral deficiencies in their livestock without buying in supplementary minerals. Everyone is very keen to find out which plants give them the mineral levels they require. The research is very relevant to the practical concerns of the group, as farmers are delighted to find out that plants like chicory contain three times the amount of calcium that grass does.

How have diverse leys become more popular over the last few years?

Over the last three or four years, there has been an uptake on diverse leys to combat wormer resistance. In 2003, at Aberystwyth University, it was discovered that by grazing sheep on Birdsfoot trefoil and chicory, vs ryegrass and white clover the faecal egg counts in the lambs grazing the swards were reduced. However we quickly realised that this wasn’t the only thing herbal leys were good for, with Massey University in New Zealand finding higher growth rates for lambs on diverse herbal leys in comparison to rye grass and white clover.

With fertiliser prices continuing to rise, herbal leys have a lot going for them; you’re improving biodiversity, less worm burden, better growth rates. So that’s why the entire organic group have embraced them!

How is the trial progressing?

I’m building up my samples before I send them off the lab. I’m looking to achieve up to 200 samples before I send them off to be tested, as it’s more economical this way. We’re only on 20 samples at the moment so we have a little way to go.

Is there anything else you’d like to achieve with the trial?

Once we have the test samples of different plants in the herbal ley in the lab, it might be worth also studying the compound in the herbs that leads to the faecal egg count of the worms being reduced, because at the current time nobody knows. It is said that herbs have contain lactones, which reduce worm burden, but no one knows the level of lactones in each particular herb – so that would make a really interesting study on top of the trial we’re already doing.

Why are farmer groups and farmer-led trials important?

It’s all about farmers learning from other farmers. It’s about farmers coming out and being shown the benefits of embracing new techniques.

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