How a dairy farm grows quality grass without artificial nitrogen

The only nitrogen used to grow grass at Treclyn Isaf, Eglwyswrw, is the dairy farm’s own slurry and clover.

As organic farmers, the Jenkins and Rees families farm by the principle that feeding the soil and looking after soil life brings benefits to every aspect of their farming business.

“Healthy soils plus healthy stock equals a profitable farm,” says Aled Rees, who farms Treclyn Isaf with his wife, Hedydd, their son and daughter, Owain and Mared, and in partnership with Mr Rees’s uncle, David Jenkins.

See also: Advice on using fresh grass analysis for nutritional value

Owain, Hedydd, Aled and Mared Rees © Debbie James

Organic conversion

The family has been farming organically since 2001, a decision initially driven by economics.

They had previously been farming 61ha (151 acres) on another farm near Cardigan, a land base that restricted herd size to 75 cows.

There was no opportunity to increase cow numbers to produce more milk, but what could be improved was milk price – by converting to organic production.

Since then, more land – both owned and rented – has been acquired. The business, Jenkins and Rees, now farms 384ha (949 acres) in Pembrokeshire and Ceredigion, milking 400 cows in a split block-calving system.

Pasture management

High-quality, home-produced feed is key to achieving 4,010 litres of the 7,333 litre annual average yield a cow from forage.

This is one of the factors that helped the family win the 2022 British Grassland Society Grassland Farmer of the Year competition.

Grazing by tack sheep is used as a management tool to rejuvenate swards ahead of spring turnout.

The farm’s heavy soils mean grazing cows late into the season will cause poaching. Turning in sheep instead, to nibble the sward down, stimulates the plant to regrow.

Milder winters, crown rust and other grass diseases become more of an issue too if heavy covers are carried through the winter. The Reeses find that a good solution to this is to sweep around fields with sheep.

Paddocks are grazed to a residual of 1,300kg dry matter (DM)/ha, with the sheep leaving the farm in the last week of December to allow regrowth before turnout.

Contractors then apply 6,250kg/ha of slurry with a dribble bar, and in-house applications at rates of between 3,750kg-5,000kg/ha are made after grazing or cutting.

Slurry is treated with a calcium carbonate-based liquid humus additive to help reduce losses during application.

Fields are soil-tested annually to inform applications of phosphorus and potash, with Tunisian soft rock phosphate used on the silage ground at a rate of 187kg/ha annually.

If fields have a soil index of below 2, the Reeses can apply to the farm’s certification body for a derogation to spread sulphate of potash. No derogations have been applied for in the past two years.

A foliar feeding system was recently introduced with humic acid in powder form, magnesium sulphate and a salt product containing 90 different trace elements, dissolved and applied through a conventional sprayer.

The herd at Treclyn is turned out in mid-to-late March, grazing paddocks in rotation to a target grazing residual of 1,650kg DM/ha to maintain high grass quality and encourage growth.

When growth is low, specific groups of cows are buffer-fed.

Pre-mowing paddocks after the fifth or sixth rotation freshens up the sward, though this is avoided in wet conditions as the cows will not eat wet cut grass, says Owain.

© Tim Scrivener

Reseeding

Weekly grass-measuring on the grazing platform provides data to inform the reseeding policy.

The performance of silage fields is also reviewed throughout the year, with any fields that need reseeding going into the arable rotation.

In this rotation, winter forage rye and vetch are grown in year one as feed for the autumn-calving dry cows, harvested in June and followed by a crop of forage rape.

In year two, fodder beet is introduced and, in the third, barley and peas are undersown with grass and clover.

Grazing and silage fields are aerated with a heavy spike roller. If certain areas of fields have been poached, they are reseeded using a fold-up chain harrow fitted with a Stocks Fan Jet seeder box.

Seed mixtures are mostly off-the-shelf varieties, incorporating as many Aber varieties as possible. Mixtures for the grazing fields have a high white clover content. For silage leys, white, red and crimson clovers are used.

The main form of weed control in the reseeds is growing cereals in the rotation. For established grassland, it is down to grazing management and a multicut silaging system.

Aled reckons that topping and hand-cutting or picking weeds are the most efficient ways to deal with problems that might arise in an organic system.

Hard grazing when needed also suppresses the most common grass weeds, he adds.

Feeding

Five cuts of clamp silage a year are taken, the first cut at the end of April and subsequent cuts every five or six weeks, with the aim of ensiling about 3,000t at 10.5t/ha DM.

The 2022 first cut analysed at 35% DM, a D-value of 73%, metabolisable energy of 11.75 MJ/kg DM, and 15% crude protein. 

Only silage and fodder beet are fed in the winter ration, as out-of-parlour feeders provide cows with concentrates according to yield, up to a maximum of 8kg/day. Up to 3kg of concentratrates is fed in the parlour too.

Herd management

The main herd – 300 autumn and spring block-calving cows – is milked at Treclyn Isaf, while about 100 cows in their final lactation see out their productive life at the original unit at Trefere Farm, nine miles away.

This arrangement makes the system more efficient as the breeding and calving is concentrated at Treclyn Isaf.

Calves remain there until they are three days old and receive six feeds of colostrum before being transferred to Trefere.

They are weighed weekly and weaned according to weight. The target is 100kg, which is mostly achieved by week 10.

Jersey genetics were introduced two years ago into what had been a pure British Friesian and Friesian Holstein herd.

The aim was to improve milk solids to maximise returns from the business’s constituents-based supply contract with Rachel’s Organic. Butterfat currently averages 4.5% and protein 3.27%.

To further improve fertility, feet and legs, the first three-way cross from Viking genetics will be born this spring.

The Viking-cross is a Scandinavian Red on a Holstein-Friesian cow with the aim of producing the VikingGoldenCross. A Viking Jersey will be introduced next and then a Viking Holstein. 

Two-thirds of the herd calve in an autumn block and 100 from 6 February, with all replacements born in the first three weeks from sexed semen.

In 2022, the submission rate for the spring block was 80% in the first 21 days, and 90% for the autumn block in 2023.

“Based on a 50% conception rate we will have 130 replacements born in the first three weeks of calving in the autumn,” says Owain.

The Rees family will host a British Grassland Society open day at Treclyn Isaf later this year.