Agroforestry – What can it offer land managers?
The integration of trees and shrubs into a farming system is not a new idea, but the adoption of the concept is gaining momentum.
6 minutes to read
Earlier this year the government published its new plan for tackling climate change through reaching net zero by 2050. It has ambitions for 10% of arable land being farmed through agroforestry by 2050.
So, what is agroforestry all about, and how can it benefit the land manager and the wider environment? Here are my learnings from the first dedicated annual Agroforestry show in Britain held on Helen Browning's Eastbrook farm, Wiltshire, in September 2023.
There's an agroforestry system for every farm
The Woodland Trust defined agroforestry as: "a collective term for the deliberate integration of trees into farming systems. It includes traditional practices such as heritage orchard grazing, farm hedgerows and parkland, and innovative systems such as growing alleys of productive trees through arable land and forest farming."
Agroforestry advocates talk about four main systems
- silvopasture – animal grazing around and under trees within an orchard or woodland
- silvoarable – arable crops grown in alleys between rows of trees
- agrosilvopasture – a mixture of grazing and forest farming
- hedgerows, shelterbelts, and riparian buffer strips
In reality, many farms are doing a form of agroforestry without really realising it. But even if you are not, it is possible that one of the systems above could fit into your existing farm and estate land.
Trees provide more benefits than you think
One of the big takeaways for me was the wide range of benefits that trees could provide as part of an agroforestry system. Some areas are still being researched to gather the evidence, but the experience of many of the current practitioners included:
- boosted livestock welfare
- improved soil health
- managed water flow
- increased wildlife
- enhanced farm productivity
- carbon sequestration
- potential income
The blistering hot September day at the show allowed a clear demonstration of one of the key attributes of agroforestry – providing shade. From a livestock point of view, shade can reduce respiration rates and body temperatures, which can improve feed efficiency.
Shelterbelts can also help animal welfare and productivity by reducing ground-level wind speeds, allowing warmer air to flow over the animals. The latter is helpful for arable land, aiding it to warm up quicker and protecting it from weather extremes and soil erosion. During winter, soil temperatures can be up to six degrees warmer under trees.
A tree root system can also usefully bring up nutrients from deep in the soil to benefit the tree and arable crop.
At Eastbrook, they have planted rows of trees within three-metre strips, fenced off to prevent livestock damage to the young saplings. The strips are spaced 24 metres apart to create alleys that can accommodate standard machinery and equipment widths. In addition, these strips can provide habitats for wildlife, such as pollinators and useful predatory invertebrates, potentially benefiting crops and reducing undesirable pests. But also, in England the Sustainable Farming Incentive options can be used under trees in alleys.
It's all about the base
One of the challenges raised was how to ensure that the saplings had enough moisture and kept weed-free. At Eastbrook, they used wood chippings from willow pollarding around the tree bases, typically applying a 5 cm layer. However, an accidental experiment one year saw some trees that received a 75 cm deep pile left around their bases grow 2-3 times higher than other trees planted the same day but with the 5 cm mulch layer (see pictures below – left-hand trees received a deep mulch).
Although using a deep mulch would be expensive, it did highlight the importance of moisture retention and, it's also thought, soil temperature modulation.
There are carbon benefits, but no carbon code
In contrast to woodland creation, agroforestry currently lacks a carbon code to tap into the carbon credit market. Work carried out by the Organic Research Centre (ORC) concluded that the Woodland Carbon Code methodology is not suitable for agroforestry and has developed a new approach. The ORC piloted the new approach on farms and found that, on average, at 800 trees per hectare, around 10 tonnes of carbon is sequestered per year.
Specialist advisors, Finance Earth, analysed the figures and found that the current carbon credit market prices wouldn't even cover agroforestry's establishment cost. One ORC pilot farm quoted a cost of £30 per tree. The conclusion was that a separate agroforestry carbon code is not viable and that combining in a wider farm-level code would be the better option.
Don't implement agroforestry too quickly
Ben Raskin from the Soil Association gave a guided tour of the agroforestry at Eastbrook and provided an open and honest account of what he found when establishing the trees. He explained how they started with an ambitious plan to plant hundreds of trees. But subsequently, the amount of planning involved, establishment challenges due to dry seasons, maintenance time required and, of course, the investment required meant they have now slowed the planned rollout.
A planned, phased rollout of planting will allow greater focus on making sure that planted trees are given the maintenance attention required, thereby not stretching resources too thinly.
Helen Chesshire from the Woodland also Trust suggested: "Farmers need to be clear on their objectives, is it environmental services, helping livestock perform better with shade or shelter or bringing in new income/markets."
But there are barriers and challenges
An interesting statistic shared at the event was from a 2016 study that showed while almost 9% of Europe's agricultural area is devoted to agroforestry, the UK lagged with only 3.3% (excluding hedgerows, parkland and wood pasture).
Various presenters spoke about the factors affecting the low levels of agroforestry in the UK:
- historically, farming and forestry have been seen as separate industries, with little transfer of skills and knowledge between the two
- short-term farm tenancies tend to discourage farmers from making long-term decisions
- separation of policy regimes at the UK and EU level for agriculture and forestry, which failed to recognise the landscape scale benefits of tree and agricultural integration
- Defra does not provide any grants to support agroforestry in England, although this is due to be introduced in 2024 as part of the Environmental Land Management schemes. Though support is available in Scotland and Wales, the narrow eligibility criteria deter farmer and crofter uptake
But if Britain is to see an increase in the level of plantings, agroforestry will need to overcome some significant barriers. Seminar speakers cited:
- a lack of skills and knowledge to successfully design, implement, and manage agroforestry systems and identify and develop markets
- landowners and land managers having capital to invest, as lead times are long before returns are seen
- resistance to change due to cultural perceptions of forestry devaluing land and its permanent nature
Conclusion
The case studies presented at the show highlighted how agroforestry can bring environmental benefits and improve business resilience in the changing climate that all land-based businesses face. Providing additional income is possible through using fruit and nut trees and shrubs. But it does require careful planning and listening to those who now have established agroforestry systems, a certain amount of trial and error.
Agroforestry is also not in a place to take advantage of the carbon markets, although that will change.
A long-term view is crucial, considering the time it takes trees and shrubs to grow and, until opinions change, the potential impact on land values. However, by ensuring that the right tree is planted in the right place, providing good maintenance, and being clear and focused on a project's objectives, agroforestry seems to be able to deliver results that could benefit the farm estate into the future.
Main image courtesy of Wakelyns