As featured in Arable Farming Magazine
Moving forward with agroecology
by Arable Farming Magazine June 2022 issue
Hutchinsons’ new Helix farm in Newport, Shropshire, is the first to focus solely on the principles and practices of agroecology.
Following a recent and difficult decision to exit the pig industry because of the extreme volatility in the sector, Harry Heath of Whitley Manor Farm near Newport, Shropshire, is under even more pressure to make sure his family’s 200-hectare arable business will remain profitable and sustainable moving forward.
Historically, the sandy loam, irrigated land was farmed hard with a three-year rotation of wheat, potatoes and sugar beet.
But when Harry and his father started to notice a decline in soil health with slumping, loss of structure and erosion during extreme rain events – caused by intensive cultivations – they decided in 2019 to overhaul their approach Transition Harry says: “We felt we were taking out a lot more than we were putting in.”
However, the transition did not start well, with two difficult autumns in 2019 and 2020.
“We quickly realised potatoes could not form part of what we were doing if we wanted to improve long-term soil health so removed them from the rotation,” he says.
The rotation now is winter wheat, often as a blend, followed by winter oilseed rape, winter wheat and an intercrop of spring beans and spring oats (‘boats’) and the Heaths are also trying hybrid rye to assist with timeliness of the OSR crop.
The farm now only cultivates where absolutely necessary, normally ahead of OSR but Harry plans to reduce that next season.
As the new Helix agroecology farm, management decisions will follow the five key principles of regenerative farming.
However, the Hutchinsons team has added a sixth principle – keeping an open mind.
This suits Harry’s approach well.
He says: “The main principles of agroecology cannot always be followed – it’s not a religion on our farm because occasionally we have to make the decision to plough to make sure the crop is a financial success.
“We follow the principles as much as we can, as often as we can.”
Dick Neale, Hutchinsons technical manager working across the Helix network, adds: “Agroecology can be applied to any farm but there is no point looking at what are potentially major problems and burying your head in the sand and thinking nature will look after you.”
An example of this was the need to plough a field heavily infested with herbicide resistant ryegrass.
Mr Neale says: “With this significant Italian ryegrass problem across a number of fields, we knew the starting point was to understand the ecology of the weed.
“We want to minimise disturbance, but the key word is minimise – we’re going to plough this field because of the level of ryegrass in it.
“However, if we can minimise the depth of the plough, we are meeting requirements of minimal disturbance while also meeting the requirements of cultural control of ryegrass.”
Cover crops for sandy soils
JAs well as weed biology, focus has turned to soil biology within the Helix project.
Ed Brown, head of agroecology at Hutchinsons and the farm’s agronomist, says soil biology is the last piece of the crop production jigsaw to be solved and, unlike chemistry, there has been a lack of technology and analysis to measure it.
He is using a microbiometer and Eurofins tests on-farm this spring for analysis and conducted soil tests early in the partnership to provide a soil health baseline and monitor any progress.
To introduce more diverse biology, cover and catch crops are grown and grazed wherever possible on-farm.
Dick Neale adds: “Coming from the East, I’ve been told you can’t have worms in sandy soil, but we are seeing a lot of worms.
With the selection of cover crops we’re trying to add diversity but also address the fact this 80% sandy soil lacks structure because it’s just sand, so you have to really do something to take the slump out of it.”
Hairy cover crop species, including vetch, phacelia, linseed and oats are well suited to high bulk density sandy soils.
“Root diversity will help stabilise the soil,” says Mr Neale.
Soil disturbance “By then minimising soil disturbance – in this case ploughing as shallow as we can get away with – much of the root mass in the lower part of the soil will also give stability.”
In another field on-farm, trials are being undertaken to assess what impact the exclusion of glyphosate might have on soil health.
Mr Neale says: “At the moment the crop looks a bit healthier behind the light cultivation [where glyphosate wasn’t applied] and soil looks darker.
“This indicates better organic matter going back into soil and I think that’s because the light cultivation to take out the weeds is incorporating OM into the soil rather than leaving it on top.
“Incorporating it allows microbiology to engage with carbon and convert it to something useful more quickly.”
How differing soil biology favours certain species
Dick Neale has been exploring how soil biology can influence different plant species.
He planted two pots with exactly the same cover crop mixture in equal measures.
The only difference was in one pot, the soil had been in a wormery for two years.
Where there were worms, seeds established vigorously and nearly a year after planting there is a completely different selection of plants in one pot than the other.
The non-biological pot is almost completely dominated by brassica species, whereas the pot of soil heavily processed by worms is almost exclusively legumes (see above).
Mr Neale says: “People talk about bacterially-dominated or fungally-dominated soils and this is a clear indicator there’s different microbiology present, which is impacting which plants want to grow in which microbial population.
Dominated “The non-biological soil is almost completely dominated by brassicas, showing that the way we manage soil does influence the kind of weeds that grow.
“We’re still in the transition period to more microbially active soil at Whitley Manor Farm.
That’s what growers need to understand when moving to this kind of system – you don’t just go from one to the other.
“The soil with a lot of brassicas growing is good for oilseed rape but if you want to use things like clover understoreys in your wheat then you wanted to be closer to the highly biologically active soil.
Ideally it’s probably somewhere in between in reality, but this just highlights there’s lots going on we don’t yet understand.”
Crop nutrition is also becoming more biologically focused and a move to liquid fertiliser is allowing Mr Heath to add soil amendments such as molasses to feed the soil.
However, he is keen to reduce reliance on all inputs, focusing more on profit than yield in such a volatile climate.
He says: “We want to get more out from putting less in.
A good example of this is the long history of putting organic manure on and good reserves of P and K, most of which is locked up, so getting biology on side is a must.
“We use Omnia for crop and nutrition planning and interrogate yield maps to see in pounds and pence what is going on.”
Detailed soil tests assess both the buffer pH and fluctuating pH of the soil to aid crop nutrition decisions.
Hutchinsons head of soil services Ian Robertson, says: “Buffer pH is the resting pH.
Normally pH fluctuates throughout the year.
The farm’s buffer pH is 7.2 meaning we are always farming in alkaline soil so we must think nutritionally what will work best? “Detailed soil testing also allows us to understand what’s readily available and [what is] not and how we’re going to cycle it.
For example, you’ve got to know how much phosphate you’ve got to cycle.
Do the measurements and find out available P in kg/hectare.”
A Yara N-Sensor is being used alongside CF Fertiliser’s N-Min Service to measure how much nitrogen is in the soil, and how much will be available to the crop throughout the growing season, for more targeted application.
Richard Watkins, local Hutchinsons agronomist, says: “We know excess nitrogen in crops can worsen disease levels, lodging risk and pest attack.
When we apply nitrogen we are also energising the bacteria and they are very hungry for carbon.
They want easy sources of carbon in order to reproduce.
That can be in the form of certain glues that our other soil biology and fungi produce or it could be from organic matter.
Over the past several decades of aggressive tillage and excessive use of ammonium nitrate, you can see how we’re driving degradation of our soils from a biological standpoint.
“When we’re applying inorganic AN we’re not applying that carbon source, which is an unnatural plant process.
That’s all having an impact on nitrogen use efficiency.
“In terms of cover crops, we want to be growing nitrogen.
Living roots cycle the nutrients.”
The team is also exploring whether certain biological products can aid nutrient uptake including Tiros endophyte seed treatment for improved N uptake in a wheat blend and Corteva’s nutrient efficiency optimiser Utrisha.
Mr Brown adds: “We are also trialling a clover mulch understorey and looking at whether we can keep permanent clover for living roots and soil cover, and generate nitrogen for the crop.”
The ‘boat’ intercrop is also reducing nitrogen demand, with both crops seeing high yields and reduced pest and disease pressure, with zero requirement for nitrogen, says Mr Brown.
“There’s a definite synergy between those two crops.”
The need to be more flexible has triggered other decisions, including a move towards home-saved and untreated seed.
Mr Heath says: “If the weather turns against us, we no longer have a load of treated seed getting old and there’s not that outlay cost.
We haven’t seen any negatives of going down that route to date.”
Gross margins are still on par with previous farming methods, despite lower-than average yields for a couple of years, which Mr Heath puts down to seasonality rather than system change.
“We’ve learned we also have to be more patient, which can be hard when you see everyone else getting on in spring.
However, this type of farming is a lot more interesting and engaging and I’ve never come across such a like-minded community – the confidence it gives you when going down this route is fantastic.”