A Welsh upland farm with limited annual rainfall is replacing ryegrass with herbal leys to provide feed for sheep and cattle.

Trefnant Hall Farm sits in a rain shadow which means that the farm often misses out on rainfall – in 2021 its annual rainfall average was 670mm even though some of the land is at 1,000 feet and just 200mm of that fell during the grazing period.

It is the principal reason why the Jones family are replacing their ryegrass mixes with herbal leys.

“Daily grass growth is often down as low as 5kgDM/ha on the ryegrass leys during dry spells, the grass gets stressed and burns off completely or goes to head,’’ says Marc, who farms with his parents, David and Jane, on the Powis Estate farm and is the 2021 British Grassland Society Grassland Farmer of the Year.

Most of the farm’s 202ha was reseeded with high sugar grasses and white clover mixes 10 years ago, when the farm transitioned to rotational grazing, but in the intervening years prolonged dry periods are now the norm amid climate change and grass performance has diminished, from an average of 12tDM/ha to 8t; in 2018 the farm averaged just 6t.

So far 61ha have been planted with herbal mixes incorporating chicory, plantain, timothy, cocksfoot, bird’s-foot-trefoil, red clover and ryegrass; the plan is to have around 142ha down to herbal leys by 2023.

“Our priority is to have feed availability in those very dry periods,’’ says Mr Jones.

The impact on performance has been significant – on the more extreme south-facing banks, fields are now growing 8-10tDM/ha without fertiliser – fields which struggled to grow 4t of grass with fertiliser.

Many of the leys have been established after fodder beet, grown as an outwintering crop for cattle.

Fields are ploughed and sown initially with a quick growing ley incorporating red clover and Westerwolds.

Two cuts of silage are taken before the herbal seed mixes are direct drilled in the autumn.

Mr Jones favours an autumn reseed, to allow the ley time to establish before a dry period, a lesson learned after a spring reseed in 2018.

“We planted 50 acres and didn’t get rain for weeks. When we did get moisture in late July the ryegrass out-competed the other plants.

“We topped it up at half the original seed rate because we didn’t know if the seed had germinated and failed or if it was just sitting there but we ended up with a poor field of ryegrass.’’

Autumn reseeds must be sown by mid-August as the seed needs a higher temperature than ryegrass to germinate.

In fields that haven’t been ploughed, the grass is sprayed with glyphosate and direct drilled - generally in the spring.

Seed cost works out at around £185/ha (£75/acre).

Soil fertility is important – the soils at Trefnant Hall Farm are at pH 6.2 or 6.3 and the P and K indexes average 2.

No nitrogen is applied at establishment.

Weed control is important – thistles, docks and other perennial weeds are sprayed the year before establishment.

The leys are grazed at opening covers of 3,500-4,000kgDM/ha, to a residual of 2,000kg.

“We will graze a mob of 300 cattle on paddocks of one or two hectares, depending on the time of the year, and move them every one or two days,’’ says Mr Jones.

Leys are rejuvenated every three or four years by overseeding with a unidrill or a harrow and air seeder.

“There is a cost to this but there is no fertiliser applied to the herbal ley so that cost base is much lower than ryegrass, topping up makes financial sense,’’ says Mr Jones.

He is now moving away from the original seed mix which was nearly 50% perennial ryegrasses, to one with just 13.47% ryegrass.

“The ryegrasses need a 21-25 day grazing rotation but the herbs and legumes 30-35 days so we were finding that the ryegrass was going to head. And in a poor establishment year the ryegrass outcompetes everything else.’’

A root and soil conditioner of humic acid, molasses and fulvic acid is included in the mix, to increase the plant’s root system and to promote uptake of glyphosate; by using this Mr Jones can reduce glyphosate use by 20%.

There is a drawback with a high percentage of herbs and legumes as they can’t be grazed in wetter conditions – they can be soft and there is a high risk of poaching, he adds.