Farming following regenerative agriculture principles isn’t always sunlit uplands, as shared by speakers at the recent BASE-UK conference. CPM provides insight into their challenges and the solutions they’ve identified to overcome them.
“What you have to think about all of the time is how you can drive photosynthesis.” – DR KRIS NICHOLLS
By Mike Abram
Growers frustrated by a seeming lack of progress following the adoption of regenerative agriculture principles often comes back to not adding enough carbon into the system, according to US soil scientist, Dr Kris Nichols.
Speaking at the BASE-UK conference, she noted experiences in North America where farmers and ranchers became frustrated after employing regenerative agriculture for a few years, even decades, and not finding the improvements they expected.
“Why is that?” she asked. “Part of it goes back to carbon and not thinking about the role that it has within the system.”
Many experience a leap forward when they switch to a no-till approach but then find the system stagnates, said Kris. “Stopping tillage stops the bleeding – the carbon loss – but it doesn’t add any.
“We tell ourselves that leaving residue will add carbon, but it doesn’t add soil organic matter carbon. Most of the carbon formed goes back into the atmosphere as carbon dioxide within a year or two,” she explained. “The job of residue is to provide armour and protection for the soil surface.”
Midwest US growers could tick the boxes for other regenerative agriculture principles, for example, by occasionally growing a rye cover crop after soybeans, or having a neighbour sporadically graze land with cows. Some even consider corn followed by soybeans as a diverse crop rotation, suggested Kris.
“But none of those are adding a significant amount of carbon. What you have to think about all of the time is how you can drive photosynthesis.”
It’s this which provides food for soil microbes, she added. “That’s the one thing you have to do as then they’ll do a job and help you out. The more we stimulate biological activity, the more we get carbon that matters – the active carbon that helps to prevent nutrient loss and improve water holding capacity.”
Kris emphasised that farmers should understand whether a field activity adds or takes away carbon. “And if you’re taking carbon away or not adding it, think about what you can do to start adding it – what’s your recarbonisation plan?
“You’re not always going to be adding carbon – that’s the reality – but understand what is it that you’re doing to add it into the system to drive forward momentum.”
Northumberland farmer Stuart Johnson could relate to initially being frustrated with the results from a switch to a soil-health-focused system. Initially motivated by cost savings, especially for inputs, he experimented with cover crops and no-till on what had been a predominantly conventional mixed farm operation.
“The early years as I call them, between 2012 and 2018, we were very scattergun in our approach – just trying different things,” he explained.
“We had some good successes but we were also doing things we thought were helping but actually doing more damage. It was two steps forward, and three steps back.
“We were incredibly economically-focused, saving as much as possible to generate margin, but there was very little thought process for the health of the soil which ironically is the keystone in earning the right to reduce inputs.
“We’d designed a system for how we wanted to farm and then were forcing our will – our way of farming – on the environment without necessarily considering if it fitted the system.”
PRINCIPLE-BASED SYSTEM
The turning point was following Understanding Ag’s principle-based system created by Gabe Brown, Allen Williams and Shane New, said Stuart. That moved him from a place where he was drowning in the science of soil function and microbiology to one where he could adopt principle-led practical solutions to drive ecosystem function, he explained.
That included daily movement for the beef herd and changing breeds to stabiliser cattle, Innovis forage-based sheep genetics that suited his system better, going to a full no-till system with a SimTech drill rather than using a Claydon, and growing multi-cover crops or diverse swards.
“I can’t advocate enough how important livestock are in terms of building soil health,” he said. The benefits include higher grass growth which reduces the feed requirements of his arable crops – allowing the farm to switch to a 5:2 rotation of five years of legume herbage swards to build soil health, before cashing in with two years of arable crops.
“We’ve gone from fairly high input to low inputs – we’ve not applied bagged P or K for seven years, no fungicides or insecticides for five years, and reduced total N applications from 70-80t/year to less than 10t.
“It boils down to at a very basic level, having living roots to build soil aggregates at depth, to make the soil work for us and allow the reduction of inputs. Yields are slightly back, but the margins are there still and we’re more resilient to price changes and weather extremes,” he shared.
Integrating livestock into an intensive vegetable production business was certainly challenging, along with implementing the other core principles of regenerative agriculture, explained John Sansome, farm manager at G W Revill & Son in Worcestershire.
Growing eight different vegetable crops from tenderstem broccoli to niche offerings such as baby courgettes, plus combinable crops, John was finding some principles easier than others to introduce at the Vale of Evesham-based business.
However, among his successes has been reducing soil disturbance using a Horizon SPX strip-till cultivator for crop establishment. “When we get it right, the results are exciting. We can spray off a cover crop, then mow and strip-till in one pass before, for example,” he said.
“There’s no bare ground between rows – the soil is protected. We have a diverse cover crop, keep a living root and move the minimum amount of soil to establish the crop. The only thing missing is livestock integration,” said John.
Sheep from a neighbour graze some cover crops and cash crop residues on the farm, but Red Tractor rules add complications. “Depending on the following cash crop, there are different periods of time that must elapse between grazing and drilling,” he noted.
Furthermore, drilling into a cover crop or previous cash crop residue hasn’t been straightforward in all veg crops at the farm. “Balanced against protection of the soil surface, we must get tiny seeds into the ground with a high level of accuracy as spacing is so important for a consistent crop,” highlighted John.
“Current veg drills can’t cope with trash and block, so sometimes our regenerative system falls down at the end because we can’t get our cash crop in the ground effectively.”
In that situation, John has reverted to the plough, although the area worked is now just 15% compared with around 130% in the past, when land was sometimes ploughed twice in one year for two veg crops. “A veg drill that can cope with trash would help us to make the next leap forward,” he said.
A more balanced rotation allowing greater use of cover crops would also help, but a combination of the market-led nature of the business plus soil types and water availability make that difficult, shared John.
Ultimately, balancing profitability and sustainability would remain a difficult act until supermarkets became more genuinely interested, he suggested, with final decisions likely to prioritise price, and length and security of supplies.
This article was taken from the latest issue of CPM. Read the article in full here.
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