Agroforestry: Learning From Four Pioneers

Written by Mike Abram

Interested in agroforestry, but don’t know quite where to start? Four pioneers shared their expertise in an
excellent knowledge exchange session at Groundswell.

More farmers and landowners than perhaps ever before are starting to consider agroforestry as a viable enterprise for farmland. Recent government announcements to treble annual tree planting in the UK by May 2024 as part of climate change mitigation and net zero targets is helping to set the agenda. While that might be in the main for woodland creation, Defra has also recently approved an Environmental Land Management Test and Trials proposal from the Organic Research Centre and partners to explore how farmers can integrate agroforestry at scale.

That followed on from the Climate Change Committee, the UK’s independent adviser on tackling climate change, recommending 10% of the UK’s crop and livestock area should be agroforestry. The Woodland Trust suggests that would require an extra 39,000ha of agricultural land for agroforestry each year, which by 2050 could deliver 6 million t/ha CO2e in savings. Currently only 3% of UK’s farmed land is estimated to practice agroforestry, and that shows with technical advice and support only just starting to come on-stream. Early adopters, such as those on a panel at Groundswell, have had to rely on trial and error to make their schemes work, and were able to share some valuable experience on five topics during an hour-long session.

  1. Selecting the right tree

Identifying tree crops with market demand was a key focus for Dartington Trust’s 19ha Broadlears Field agroforestry project in Devon, said Harriet Bell, who helped establish the innovative land share agreement between five businesses. “We found people who had specific demands, qualities and quantities, and we endeavoured to design a system that will deliver that outcome. “The other thing we did was try to spread the risk with a variety of different trees. We tried something new in Szechuan pepper, which hadn’t been grown here before, but in a small way compared with staples such as apple and elderflower which we knew would grow well in Devon.

In a silvo-pastoral project also on the farm, understanding livestock behaviour and dietary needs were key considerations, she added. For Cambridgeshire farmer Stephen Briggs an economic return within his 15-year tenancy was a pre-requisite for tree choice on his 52ha silvoarable scheme, alongside the need at the time to maintain Basic Payment Scheme eligibility for his landlord. That led him to choose 13 varieties of apple from heritage to modern. With no other fruit trees in the immediate area of his farm, it has meant lower pest and disease pressure, although selecting trees that will grow in your locality is important.

Other factors to consider were soil type, good planting stock and being able to buy it, he added. “That’s going to be an increasing challenge with the government’s tree planting targets – where is all the planting stock going to come from? You have to be thinking nearly two years ahead,” he advised. Climate change was another factor to reflect on both in terms of spreading risk of pest and disease pressure, as well as for future markets, he said. “People are starting to think about, with climate change what we might be able to grow in southern England, which we can’t grow currently.” Examples potentially were almonds, olives and Eucalyptus. 

Your own farm could also be a market for produce from trees, said Ben Raskin, head of agroforestry for the Soil Association. “You could be growing your own fence posts or wood chip. There’s lot of stuff you could grow to replace your own inputs.” Multi-purpose high-value trees from which you get more than one product could be important, said Prof Steven Newman, who assists with the development of large-scale agroforestry projects on farming estates. “Nut trees fall into that category, particularly walnut and hazel.”

For example potential walnut markets included fresh walnuts, green nuts for pickling or for Greek / Cypriot sweet desserts, and timber, he explained. “There are at least 60 different products you can get from walnuts.” Be innovative, he advised. “Globally there has been a 20% increase in nut consumption over the past seven years. That’s a massive shift. Nut milks have an incredible potential, while think about replacing carbon inefficient products.” 

Payback year for walnut was year seven, and year five for hazel. “After that you are into some quite significant gross margins, but it’s not instant. The payback year depends on the cost of the tree, which is the dominant cost. Buying bigger orders reduces the cost per tree. “The most profitable tree currently is cricket bat willow, which is a classic choice for a silvo-pastoral system. Nut trees, especially walnut, agroforestry can improve on this, providing an annual income, plus a final value from the tree when it has finished its productive life.”

  1. Planting and managing for survival

Planting trees into heavy clay was not easy, Mr Raskin said. On such a site he used a GPS-guided subsoiler to create a straight line and a slit to plant into, which made planting quicker and gave reasonable establishment. “But in 2018, when we had the drought, the trench we created just split open so there was a 1m crack in the soil in which this poor little twig was sitting in and had nowhere to grow. “So I think next time I’d plant about six inches to one side of the crack so you’re not directly in it.”

Planting date was also important – January-planted trees mostly survived while those in March mostly died – as was mulching, he said. “But I wouldn’t use mulch mats – they create the perfect habitat for voles, whereas where we just used wood chip to mulch directly, we tended not to have problems.” Whether to use guards or fencing was a cost versus risk debate, he said. “It’s the value of the tree and how many trees you have in the field. For example, in one field where we had a lot of expensive fruit and nut trees, and it was worth deer-fencing the whole lot. “In another field, we just have single strand electric wire down each side of the row, with a little guard on each tree for hares and muntjac, and it’s much cheaper. We feel we can lose quite a few trees before it’s worth spending £30,000 on fencing.

“Straight lines are obviously easier to fence, whereas if you have clumps of trees, you’re probably better off doing them differently or individual trees.

“In the end, how much can you risk losing that tree? If you’re spent £0.50/tree and a £1 on a guard you can probably afford to lose quite a few, while if you’ve spent £25/tree and you’re not going to get a return for 10 years you probably want it to survive.”

Buy good quality posts, Mr Briggs said. “We bought on a budget, and after three years when they’ve rotten at the base you have to spend all over again.” It cost him approximately £5-7 to put a fruit tree in the ground, including mulch, tie, guard and posts. In his arable system, he hadn’t anticipated creating 4,500 roosting posts for pigeons, where two or three landing can break young saplings. “We solved that by putting a 10-foot bamboo cane with each tree, which the pigeons landed on.” Also think about what you’re doing underneath the tree, what understory will grow well and how you’re going to manage it, he said. “I wish we had put a weather station in from day 1. We benchmarked a lot of things, but I know we have wind reduction and warmer climates in the field, but I haven’t got the backup data on that.”

3. Harvesting

Think carefully about labour for harvesting, Prof Newman said. While community labour might be an option for some, the lack of available labour for picking was driving a change towards mechanical harvesting. “All the large-scale systems we’re designing for nut trees are mechanically harvested. That means changing the hazelnut varieties, so they are free husking and means when you shake the tree the nuts come down relatively swiftly. “Similarly with walnuts when they fall to the ground they can be picked up,” he explained. It wasn’t just harvesting labour to consider but also for summer or winter pruning, Mr Briggs added.

With apple trees in most systems you wouldn’t get any yield for around five years, with yields peaking after about seven years. “You should be looking at least 5t/ ha up to 20t/ha if you’re managing quite intensively.”

Another consideration was the impact of harvesting tree crops on the crop in between the trees, Ms Bell said. “When we were designing our silvo-arable system we were looked at when we would be taking a cut from our arable part of the field, and when we would need to be in with heavy machinery to harvest the trees and tried to design the whole system with that in mind. “For example, with elderflower which is usually harvested in May or June, we put in a wider margin around those trees so we could still get in and harvest without it having a detrimental effect on the arable crop.

4. Marketing

Adding value when marketing produce was key because competing on price in a global market was unlikely because of high labour costs and standards in the UK, the panel explained. “We were interested in adding value from the start,” said Mr Briggs. “All our fruit is either sold as eating apples or juiced and sold through our farm shop. We wanted to generate a market, get some processing capacity and create a brand for that produce.

“By juicing our apples and putting it in a bottle, while there is a cost, you’re pretty much quadrupling its value. You’re turning something that was £280/t on the wholesale market into £1200/t.” But as with stock markets demand and value of products could change and with that future returns, the panel noted. For example, currently cider apples were generating a poor return, Mr Raskin said. “I wouldn’t be considering cider at the moment – the value has dropped out of the market.” 

While spreadsheets were useful to model potential future risks, trees within typical agroforestry schemes were only 8-12% of the land area, Mr Briggs pointed out. “So around 90% of the area is going to be doing something different so you are spreading your risk.”

Agroforestry had other benefits including sheltering livestock or raising the temperature between the rows in arable crops, Mr Raskin added.

Shading up to 27% of a potato crop didn’t affect yield in Prof Newman recent research, while Ms Bell suggested agroforestry also helped manage the risk of unpredictable weather. Storms during 2019 harvest on Mr Briggs’s farm resulted in 20% loss of grain in open fields compared with 10% in agroforestry fields because of slowing down wind speeds, he said.

  1. What options do you have as a tenant?

With nearly a third of the land area in the UK tenanted, the issue of whether agroforestry is deliverable as a tenant is no small matter. At Dartington, a novel solution was used, Ms Bell said. “The Estate owns the land, we have a tenant with a FBT for the entirety of the field, and then we used licences to licence each of the tree growers for just the row of trees they were growing. Our tenant was paying the estate, and the people growing trees paid rent to him.

“Legally it was quite interesting as the tree growers in the first few years were investing quite heavily in getting trees to productivity, but then worried that when the trees became productive we would turf them out. “So in the agreement we wrote that the cost of moving them on would increase during the first eight years as the trees established, and then once they started harvesting and getting their money back, the value of those trees would start to depreciate. “And as the landowner we also underwrote the licence between our tenant and those businesses growing the trees so they had security if the tenant changed.”

In Mr Briggs case his landlord was most concerned about letting the farm if Mr Briggs left, and whether it would damage field drainage. “We signed an agreement that we would take the trees with us if we left, so at worst I have a wood fuel business, and I found a piece of work that showed if drains are maintained trees don’t cause any problems.” 

Farming with trees had allowed him to become more productive, he suggested. “I’m charged rent on a two dimensional – per hectare – basis, but I can make the farm bigger by farming it in a 3D way and make it more productive without affecting the rent at all.”