Tackling big questions with on-farm research
As featured in Arable Farming Magazine
Tackling big questions with on-farm research
by Arable Farming Magazine August 2022 issue
Regenerative farming, drainage and economic performance mapping are among the projects underway on AHDB Strategic Cereal farms.
Hampshire soil-centric farmer David Miller joined AHDBs Strategic Cereal Farm network last June.
He hopes the programme will allow other farmers to make the transition to regenerative farming faster and more smoothly than he did.
He says: The whole point of the Strategic Farm is to understand the transition, the drawbacks and the pros and cons as we go along, to help others perhaps have a six-year journey rather than the 12-year journey weve had to get to where we are.
Mr Miller was thrown in at the deep end in his transition, pushing the whole farm into a regenerative system in one go, during a time when few people had done the same.
Transition The mistakes were not made on a small area.
My advice would be to just try bits first and see what works across your acres.
Take fields that are more productive before worrying about putting the more difficult fields through the transition.
We still have fields that are more reluctant to take on the new system.
They are now in two-year stewardship legume mixes to help them along.
It is about using all the tools in the box.
Although Mr Miller feels the fundamentals for a productive and regenerative system are in place on the farm, he expects the system to continue to develop.
It is a dynamic process that as we continue to improve soil health then something else will change, he says.
For example, in the early days of the transition some crops were slow to get away.
They looked awful and we didnt know why.
We found out we werent mineralising any nitrogen because of having no cultivations, so we had very inert conditions for the crop to get away in.
That took us to putting DAP down with the seed with permission from the Environment Agency.
We did that for six years, gradually weaning ourselves off it and now we are trying biological food products in trials.
He hopes that as the Strategic Cereal Farm South host, he will be able to prove a system that will work across a wide range of broadacre farms.
Science Trials underway on the farm are helping to put the science behind some of the work Mr Miller has already done in terms of soil health and transitioning to regen.
NIAB crop and soil science researcher, Dr Callum Scotson, who is leading the trials, says they are being conducted in a way that farmers can replicate on their own farms.
This includes exploring three different cover crop mixes grown in 18-metre strips and comparing these to bare stubble and a neighbouring field of winter wheat, to explore the effect on water quality, nitrate capture and improving soil structure.
Dr Scotson says: We found that the cover crops in the regeneratively-managed fields have been really successful.
They really took off and provided good coverage.
But in the fields previously conventionally managed the cover crop just didnt take, there was poor establishment and groundsel was the major component of biomass.
A VESS assessment found structure was notably poorer here.
We are looking at the transitionary period and how long it takes for a cover crop to be successful, as well as yield, and crop health and disease in the following crop.
Trials With more biological products coming to the market, tramline trials are also exploring whether products L-CBF Boost and Ecoworm can aid early crop growth and establishment, with better mobilised nutrients.
Boost is a product that Mr Miller uses across the board already with all nitrogen applications to try and buffer the effect of soil biology.
He says: We are beginning to make a clear line between products that are a sticking plaster and things that promote beneficial soil biology.
Just adding biology to the soil is very expensive and might not be what you need if it is going to antagonise what is already there.
Were looking for a more natural way of moving it forward rather than a chemical way.
Dr Scotson adds: Soil microbial communities can be quite delicate and a niche structure.
If found to be effective, there may be a role for these products - particularly in the short term.
Long-term, it could be better to focus on building up what you have there and that innate diversity rather than trying to solve it exclusively with a spray on solution.
Nutrients One area Mr Miller is keen to explore is how the nutrient density of his crops stack up compared to those grown in a more conventional system.
It is a theory being bandied about.
We have very healthy soil, we therefore have very healthy plants which then, we think, creates very healthy food.
However, the definition of a âhealthier grain and what is driving it is yet to be determined.
Samples from two different systems are being sent for nutrient analysis, which will look at fat, carbohydrate, protein and micronutrient levels.
Of course, it would be nice to then be able to sell our products at a premium, but if its costing us less to grow Im not sure a massive premium is what we should be aiming for.
If we can produce 9t/ha of wheat that has the same nutrient content as 12t/ha of conventional wheat then I think we have a good base to work from in lowering our inputs even further, says Mr Miller.
Supporting decision-making with economic performance mapping
Being able to identify opportunities on-farm to deliver public goods will be essential as the transition to the Sustainable Farming Incentive (SFI) progresses.
The identification of economically marginal land is a key factor in this respect.
At the AHDB Strategic Cereals Farm East summer meeting, NIAB soils and farming systems technician David Clarke shared details of a project which is focused on producing an economic performance map of the farms cropped area for host farmers E.J. Barker and Sons, Westhorpe, Suffolk.
The aim is to determine whether economically poor performing areas could be better managed for profitability and environmental outcomes.
Data sources available for use in the analysis include combine yield maps extending back over 10 years, across 513 hectares.
We looked at 35 fields and we have spatial yield data for about 75% of all the crops grown, said Mr Clarke.
Where yield maps are being utilised, a key question is whether they are accurate enough and contain enough detail to use for analysis and there are things farm businesses can and should do to ensure their data is fit for purpose.
The first thing we did to the data was clean it; we developed a couple of steps to do this.
We basically removed any data points that were too far apart or too close together.
Time stamp We worked out swath spacing using the time stamp and where the swath was too close to another we assumed the header wasnt full, so we removed .
We removed all points where the combine was turning and any yield outliers.
That gave us a much cleaner yield map.
If you are using yield maps to calculate your margins, try and use some of the software available to clean yield map data sets.
It is important to do this.
Across the data set here we had nearly a million data points across the 10 years, and we had to remove about 16% of these because they were not realistic.
In addition to yield mapping on the combine, Strategic Cereal Farm East host farmer Brian Barker also records crop offtake using grain trailer weigh cells, so the next step was to correct all the yield map data based on the recorded offtake.
Mr Clarke shared an example of one field in which the uncorrected mean yield was 13.5t/ha, while the recorded offtake mean yield was 10.6t/ha.
If you are collecting yield maps on-farm and using them to make informed margin decisions, you really do need to have another data set to compare with whether weighbridge yields or grain trailer weigh cells, he said.
Recorded Plotting the weigh cell-recorded yield against the combine yield data revealed most data points fell within a 10% margin of error.
The mean absolute error across all 171 wheat yield maps was 0.79t, which at a wheat price of price of £300/t equates to £237/ha, said Mr Clarke.
We had our cleaned yield maps 258 across the farm, 65% of the rotation so we needed to try and make sense of them.
We wanted to identify areas that were consistently poor performing or were consistently high performing.
We used a method called clustering, which looks at patterns in a data set using a machine learning algorithm to segment a yield map into zones which perform the same across years.
This gave us 158 zones across the farm basically breaking the farm up into homogenous yield zones which we can expect to perform the same.
On average zones were about 2.9ha in size, so reasonably large, and up to 10ha.
For each of these zones the Barkers now have information on average yield performance, which they can confidently use as a predictor of expected yield performance and make and review margin calculations based on current prices.
We can make decisions based on an annual price variance and the yield potential of the zones.
And we confident in those zones yield potential because of all the correction and cleaning we have done, said Mr Clarke.
A focus on drainage and soil structure
The opportunity to be involved in a six-year project aiming to identify the factors that limit yield and trialling different methods to overcome those barriers is something Yorkshire arable farmer David Blacker is looking forward to.
He is hosting the latest of the AHDBs Strategic Cereal farms this time in the North.
A third-generation arable farmer, he farms 200 hectares at Church Farm, Shipton, on the northern outskirts of York, as well as providing a farm contracting service.
He has previously been a monitor farm host and is keen to make the most of the longer-term opportunities the Strategic Farm project offers, including access to research which can be trialled on-farm.
Speaking at the well-attended launch in mid-June, he explained that the farm had grown sugar beet as part of the rotation in the past but had ceased to do so when the local factory closed.
Now, his rotation focuses round first winter wheats, along with spring beans and vining peas.
We have every type of soil in our fields, and it changes very quickly across fields.
They are predominantly clay though, and are badly drained, he said.
Drainage is a clear issue.
We used to grow sugar beet in this field, and I think compaction has had a huge impact.
There is a pan at 22 inches and we cannot seem to sort it out.
Drains Mr Blacker has found that while cover crops have helped to an extent, the problem requires a fundamental investment in drains.
However, Mr Blacker said contractors were very expensive and often not available when his soils were in a fit state to drain.
So, he decided to buy his own draining equipment, and aims to drain 8ha of the farm each year.
It is a quick and effective way of emptying your bank account, he said.
He is, however, providing some draining services now to other farms, and reinvests any income âback into pipes and stone.
A drainage trial is one of the first pieces of work to be done at Strategic Farm North.
Instead of the usual 20-metre spacings, Mr Blacker is trialling lateral drains at 10m, 15m and 20m intervals.
He believes this might help the farm and its soils better cope with the increasing intensity of rainfall when âthere may be no rain for six weeks, but then three inches all at once.
To provide a comparison, part of the field is to remain with the old drain system and one corner will remain undrained.
Trial The drainage trial will also include soil analysis of each of the three areas to assess whether soil microbes are dying over winter as the soil becomes waterlogged and anaerobic.
The research will also look at the time taken for the soil to restructure and increase in porosity.
I know drainage and soil structure are my big issues, and I want to look after the soil better, said Mr Blacker.
With that focus in place, and the Strategic Farm North running until August 2028, there will be plenty of opportunity to see how new approaches work in a commercial setting.