Rethinking organic farming: from soil to cow

Led by Wil and Jess Armitage, Biolog­ical Farmers is a collab­o­ra­tion of UK farmers, put together to show farmers how under­standing science can influ­ence the future of their farms. In March 2024, along­side Colin Hanson-Orr from Forage Tech, Leices­ter­shire farmer Wil Armitage set up the Biolog­ical Farmers group, with the inten­tion of educating producers about biolog­ical options.  

And he’s got plenty of expe­ri­ence; he started working as herd manager at Keythorpe Farm near Leicester aged just 22. At the time, they were aiming for the highest milk yields, and won the pres­ti­gious NMR / RABDF Gold Cup twice, with a herd average of 12,000kg/cow in 2000.  

Farm owner Peter Dixon Smith offered Wil a Farm Busi­ness Tenancy, but this was not feasible, so in 2004 they started a part­ner­ship. They have since built the busi­ness up to two dairy units; a 350-cow autumn-calving herd and a 180-head spring-calving herd, both consisting of Holstein Friesian cows. Also farming one contract dairy farm. 

Tran­si­tion to organic farming 

When he first became a partner, Wil realised he could make a living as a conven­tional dairy unit but would not be able to expand the busi­ness further and gain a larger profit. So, despite some misgiv­ings from Peter, he tran­si­tioned to organic in 2005. “The farm had been in conven­tional arable produc­tion until 1990, and the soil struc­ture was appalling,” he says. “The high-yielding cows did help with this but there was more to be done.”  

The deci­sion was finan­cially driven. “The organic milk price at the time had a 10-12p/l­itre margin; suddenly we were more prof­itable than conven­tional farms and Peter began to take more notice.” After five years, profits started to plateau, and in 2013 Wil was awarded a Nuffield schol­ar­ship to study sustain­able dairy farming. Through this he trav­elled to Denmark, Sweden, America, Australia and New Zealand. 

“I found that passionate soil farmers had good crops and good stock,” he says. A former cham­pion showman and Holstein judge, he noticed that the best organic herds had the health­iest stock, with further research iden­ti­fying a link to the calcium/magnesium ratio in the soil. “So, my Nuffield then followed a different line looking at the soil more.” Wil then did a soil chro­matog­raphy course which high­lighted the synergy between rumi­nant microbes and soil microbes.  

Upon returning to Keythorpe, he analysed his own soils, although Wil hasn’t used phos­phate or potash fertiliser since 2005, indices are natu­rally high with the use of cow manure. And his perma­nent pasture is performing well: “We’ve had 28 years grazing the same ley; it’s yielding 11-12t/ha dry matter per year so I don’t want to pull it up.” Wil also grows organic fodder beet, which is valu­able in the cows’ diet. “We harvest it three weeks before serving the cows (to get them preg­nant), so they get an energy increase just before we want to start breeding,” he explains. “Once the fodder beet comes out, we estab­lish a whole crop mix of oats, barley, peas, beans and vetch, under sown with grass and clover depending on the weed burden.” 

There has been a lot of pres­sure in organic farming over the past six or seven years, and organic dairy producers have been unable to compete with conven­tional farms, says Wil. “In March 2024 we took our contracted farm out of organic produc­tion because it wasn’t gener­ating the income, but thank­fully the two other farms are still organic as the premium has gone back up to 10p/litre, which is where it needs to be in order to cover extra costs.” 

In terms of farming biolog­i­cally at Keythorpe, Wil is using silage addi­tives. “We’re limited to what other prod­ucts we can use to due the organic system that we are on, we are using the silage addi­tives recom­mended by Colin and since we have seen an increase of palata­bility across the farm.” Wil’s chil­dren Jess and Giles are both passionate dairy farmers, working on the farm, with Giles running one of the units while Jess is respon­sible for calf rearing and office work. She will also be heading up the Biolog­ical Farmers group.

“The first Biolog­ical Farmers event was held in July at Keythorpe, and over 100 people came along, which high­lighted the need and desire for it,” says Wil. He hopes that the group will grow in future. “The aim is to run a series of work­shops for farmers, starting by looking at soils, then plants, then animals in terms of their overall nutri­tion. “At Keythorpe my ambi­tions are to continue our organic dairy journey; our carbon foot­print is currently 1.01kg/litre and I’m hopeful that one day we can be net zero. It would be good to prove that it’s possible and that cows are not the problem but a vital part of the solu­tion.”

 PANEL: Biolog­ical farming – The concept 

Colin Hanson-Orr, head of research and devel­op­ment at Forage Tech, has been in the industry since 1979 and believes that biolog­ical farming is no longer just an option; it is neces­sary for the survival of UK farms. The Biolog­ical Farmers group was orig­i­nally estab­lished to help farmers cope with the chal­lenges of Nitrate Vulner­able Zones (NVZs) and other regu­la­tions. An average UK dairy cow yielding 8,000 litres/year can produce enough nitrogen in its slurry to exceed the NVZ limit of 170kg of N/ha per year. With an average stocking rate of 2.39 cows/ha, farmers would need to reduce their stocking rate by 58%, to one cow per hectare or less to comply with NVZ regu­la­tions. 

Slurry can there­fore be viewed as prob­lem­atic – but also an impor­tant source of soil nutri­tion. And treating slurry with bene­fi­cial microbes can improve this nutrient release while reducing harmful emis­sions. Bacillus is a bacterium, which breaks down slurry, making the nutri­ents – like nitrogen, phos­phorus and potas­sium – more soluble. So once in the soil, they promote root growth and devel­op­ment by facil­i­tating growth-promoting microflora and nutrient uptake. 

Ammonia in slurry can be damaging to the envi­ron­ment, but the bacillus works by breaking it down to ammo­nium. Bacillus species can help break down organic matter in the slurry, making it more liquid and easier for the soil to absorb. This means that when the slurry is spread on fields, it can pene­trate the soil more effec­tively, carrying bene­fi­cial bacteria and nutri­ents deeper into the soil profile. These bacteria also help create a better envi­ron­ment for other bene­fi­cial microbes. They contribute to the biofilm, a protec­tive layer in the soil, which supports various micro-organ­isms and also help to outcom­pete less helpful or even harmful microbes.

Using bene­fi­cial bacteria can also help with silage quality and nitrogen fixa­tion in the soil. Diazotrophs are nitrogen-fixing bacteria which take N₂ from the atmos­phere and convert it into NH₃ (ammonia), which can then be used by a growing crop, increasing produc­tivity and reducing the need for arti­fi­cial fertiliser. TwinN is a diazotroph which has been trialled directly on farms, coming in small vials which cover 1ha each. The use of TwinN over urea would enable the reduc­tion of 70kg urea per hectare, which would save a carbon foot­print 275kg of CO₂e/ha. 

Colin was one of the first people to trial silage inoc­u­lants when they first came to the UK. “The average silage dry matter loss from harvest to feed is 27%; and this loss isn’t from digestible fibre and ash, it’s from carbo­hy­drates and protein. Silage inoc­u­lants work by preventing microbes from depleting the silage’s protein and energy,” he says. Effec­tive, modern biotech­nology improves the fermen­ta­tion process of silage. A study in August 2023 compared untreated and treated maize/ryegrass silage, and found that inoc­u­la­tion increased dry matter intakes, boosting cows’ daily milk yield by an average of 2kg/cow, while also improving milk fat, protein and lactose content.