Portrush farmer William Chestnutt is trying to lower his reliance on bought-in inputs whilst maintaining output from his 260-cow dairy herd.

A key part of his approach is based on the principles of regenerative agriculture, where natural processes are used to help cut costs and improve the environment.

“My interest isn’t about going full regenerative. It’s more about seeing what regenerative can offer in terms of reducing inputs,” William explained.

He first started to question his dependence on inputs in 2015, when the milk price was 19ppl, but his cost of production was 26ppl.

“I went to the Winter Fair that year and thought we are losing money with every litre of milk yet everyone exhibiting here is getting a wage out of it.

“I just thought there has to be a better way. Ever since then I have been trying to figure it out, although I still haven’t fully managed that yet,” he said.

Wiliam is clear that the solution is not as simple as ruthlessly cutting out inputs, as some advocates of regenerative agriculture might suggest.

“There is capital expenditure in dairy farming, and you need a certain amount of output to service that. To get that output, you need to feed cows,” he said.

Nitrogen use

One of the biggest changes on the Chesnutt farm in recent years relates to artificial nitrogen, as total usage has more than halved over the last decade.

Interestingly, William said housing the dairy herd all year round and using a zero grazer during the grazing season has been central to this.

“It allows us to go on with slurry after every grazing. A ‘little and often’ approach with slurry has reduced our nitrogen bill and it’s better for the soil too,” he said.

He said slurry applications between zero grazings range from 1,200 to 1,800 gallons per acre and, during a good growing spell, he manages to cut out fertiliser applications altogether.

William has a strong interest in soil health, particularly how to improve the condition of soil biology such as earthworms, as well as invisible microbes like fungi and bacteria.

He suggests a lot of the advice about soil health in the past has been focussed on the chemical status of soils and how it can be improved with fertiliser and lime applications.

More recently, the physical structure of soil has become more prominent, such as addressing issues with compaction.

“I think this is where regenerative agriculture offers something. If you can look after the biology in your soil, then you can really make a difference to your output,” William said.

Liquid fertiliser

It is one of the reasons why he has switched from spreading prilled fertiliser to using liquid applications of foliar fertiliser.

“If you dissolve the nitrogen and put it on as a liquid on to the leaf, then it is directly feeding the plant, so it stays out of the soil and doesn’t affect soil biology,” William said.

He also suggests that less fertiliser needs to be applied if is in liquid form as there should be a more efficient uptake by the plant, and less nitrogen is lost to the air and leaching.

William initially used a conventional crop sprayer to apply foliar fertiliser, but he has now invested in a purpose-built trailed liquid fertiliser sprayer.

He has also started applying microbes and seaweed extract to help improve soil biology and, similar to his slurry applications, he goes with a “little and often” approach with foliar fertiliser.

“It works fine with grazing because you are out every three or four weeks anyway. With silage ground, I found it is best to split applications. I am still in the learning phase,” he said.

Another regenerative style innovation on the Chestnutt farm has been the decision to grow mixed species arable silage, which is made up of barley, oats and peas.

Crude protein

The idea is to increase crude protein levels in wholecrop silage so less bought-in soya needs to be fed to cows. The crop William grew last year was analysed at 14% crude protein and compares to cereal-based wholecrop which typically analyses around 10% crude protein.

“We were able to take a cut of grass silage in May, then get that crop in.

“We took it off in August, got a reseed in, then took a grazing off it, all in one year,” he said.

The mixed species wholecrop also proved a very low input crop, as a seaweed foliar was the only application given. “We got a real good strike with the reseed afterwards, which was a multi-species grass mix of plantain, chicory, clover and grass. It seemed to do a job in the soil,” William said.

Not all changes on the Chestnutt farm in recent years directly relate to regenerative agriculture.

A key example is the breeding policy which has changed so cows are now a three-way cross of Holstein, Viking Red and Montbéliarde.

“We were a Holstein herd averaging over 9,000 litres, but the cows weren’t lasting in the system. We decided to go ProCROSS just to breed a bit more vitality and longevity into the cows,” William said.

He said the herd is currently averaging 8,500 litres at 4.20% butterfat and 3.45% protein, with around 2.8 tonnes of meal fed per cow.

Whilst milk yield has dropped back by 500 litres as a result of the breeding change, butterfat and protein are well up from where they had been previously at 3.90% and 3.18% respectively.

William Chestnutt says he does not have all the answers when it comes to applying regenerative farming techniques to a conventional NI dairy farm.

“It’s very hard for us to justify switching to a full regenerative system, because where will our output come from and how do you pay the bills with that?”

The regenerative farming movement is big in the likes of Australia and the USA, but some of the lessons from these countries may not directly apply in an NI context. The likes of climate, soil type and farm size are all very different, for a start.

“In a lot of those countries, it is arid, and they have usually tilled the ground to death, so they see great improvement when they go regenerative and introduce livestock,” William said.

In NI, where over 95% of farmland is already in grass, soil degradation and a lack of carbon in soils are not the main problems facing local farmers.

“It is a lack of heat and a lack of nitrogen that we have here. The context is very different,” William said.

“I do think we need to look after our soil and make changes to how we manage the farm, but I am not sure how it all stacks up yet,” he added.

William Chestnutt is speaking at the Fields Good regenerative agriculture festival in Glenarm, Co Antrim on 7 September. Visit fieldsgood.co.uk for more information.