Hedges, Trees, and Buffers
Natural features within the landscape such as hedges, trees and buffer strips can provide shelter, habitat connectivity and protect sensitive features such as bodies of water.
Additionally, the strategic use of natural features can help aid the stabilisation of soil – reducing physical loss via wind and rainfall or through increasing organic matter content. Rooting systems and physical protection of the soil surface from features such as hedges, trees and buffer strips can build organic matter through vegetative returns and the stimulation of soil processes. The building of organic matter can also be a mechanism for removing carbon from the atmosphere, sequestering it into the soil. This helps to tackle climate change by reducing atmospheric carbon dioxide levels.
Why plant additional natural features?
- Helping reduce soil erosion, the additional rooting structures can help hold soil together. Your soil is your livelihood – keep it on your farm!
- Trees and hedges provide shade and shelter for livestock, allowing browsing livestock access to a greater array of proteins and minerals, which can infer health benefits.
- The rooting of trees, buffer strips and hedges can also benefit field drainage and the infiltration of water.
- Introducing species beyond that of managed grass or cropland can benefit synergistic relationshipswith a wide range of fungi in turn allowing greater access to water and nutrients for the surrounding land.
- Strategically positioned trees and large hedges can also be an effective mechanism for mitigating ammonia emissions from livestock housing and manure stores.
- Natural features increase the number or size of habitats on farm and are consequently a key support of a broad wide range of wildlife.
- The creation and planting of hedges and trees will deliver the long-term sequestration of carbon into plant material and build organic matter as the soil is left undisturbed.
Where to locate a hedge, tree or buffer strip?
There are no right or wrong answers to exactly what to do where. Making a measured judgement is recommended. In-depth knowledge of your farm, soils, productivity, and environmental issues can indicate where and if challenges you may feel need addressing.
Having a map of the farm to hand and sketch out your evolution of ideas and thoughts can be helpful, particularly indicating less productive or inaccessible areas which would be better suited to a buffer. Parts of the farm that are steep, wet or with shallow, stony or poor-quality soil is often a wise starting point.
Additionally, recording where established trees are currently located in fields or within hedges may indicate where further plantings may be beneficial. This may aid the management of existing and new plantings to maximise growth of the trees and also minimise on-farm disruption.
Well-located hedges, trees and buffer strip habitats can provide a range of benefits to both the farm business and mutually benefit the environment.
What planting density and arrangements should I adopt?
A natural feature expected to provide a windbreak or shelter for livestock will benefit from a linear (but not necessarily straight) arrangement of a staggered, dense and orientated broadly perpendicular to the prevailing wind direction. If however, the feature is designed to be browsed by livestock a different arrangement and planting densities would likely be more suitable.
A buffer strip, hedge or tree planting can help to mitigate the loss of soil because of erosion. The strategic planting of buffers can improve drainage and water infiltration across the landscape. Therefore, designing a planting scheme to follow a contour or across a slope may be useful to slow and hold the flow of water. Again, this would be a dense staggered planting arrangement, but may well be a thicker/wider than a standard shelterbelt depending on the scale of the erosion issues that are apparent.
What is Silvopasture?
Silvopasture is the inclusion of trees within a pastoral system. It is a type of agroforestry which provides overlapping benefits and multiple products through the combining of trees with either grass or cropping under one management system.
Well managed silvopasture can increase overall productivity and income, with multi-cropping considered one of the oldest forms of agriculture. Silvopasture is not a new idea. Orchards and parkland remain common examples that have fallen out of favour in the last 50 years as the industry has become more mechanised and dependent on agricultural inputs. Notionally there are three main planting layout options:
- Wide spacing
- Linear row planting
- Group or cluster planting.
The simultaneous production of crops, forage and livestock alongside trees can provide many environmental benefits including carbon sequestration and habitat connectivity. Consequently, the planting of fruit or nut producing trees can create a business diversification through the provision of alternative saleable products, as well as timber, firewood, or biomass.
Practical Considerations of Increasing Natural Features on Farm
One of the major practical concerns of increasing the establishment of natural features for most farmers is understanding how it will fit alongside existing mechanised operations. The planting of trees and buffer strips not only creates above ground obstacles, but for land that is under frequent cultivation, concerns about impeding tree roots are also a valid concern.
The planting of trees, hedges and buffers and the consequent splitting of fields into many smaller parcels may be for many farmers counter-intuitive to the direction of the last 50 – 60 years. However, this system does benefit the adoption of other management systems including mob and rotational grazing systems through the creation of paddocks. Grazing management could inform the layout of where hedges, trees and buffers may be best placed. Additionally, management practices such as fencing hedges and newly established tree lines will benefit the security of livestock within this system.
Whilst the trees are becoming established protection is required from 3 main challenges: wildlife, livestock, and farm machinery. The level of protection required will depend on many factors, including whether livestock will be cohabiting or grazing the field. The protection required for trees, from chicken, sheep and cattle are all different alongside other wildlife such as squirrels, rabbits and deer, so think carefully and plan wisely.
It is worth bearing in mind that the roots of the trees are core and essential to delivering many of the benefits that planting of trees will bring to the farming system so destroying them with farm machinery will curtail the benefits of such an approach.
What hedge and tree species should I plant?
Seeking guidance from specialists may introduce options which may have originally not been considered or perhaps thought to be unfeasible. Increasing the diversity of species introduced onto farms will benefit both wildlife and the wider ecosystem. New plantings benefit from being composed of at least three species for both hedges and also trees under agroforestry or Silvopasture management.
- If you are primarily looking for protection and shelter for livestock from wind and harsh weather. For dense low level wind protection: Hawthorn, Hazel, Blackthorn, Holly could be wise choices.
- For higher level wind filtration or ammonia capture from sheds or slurry stores: Alder, Birch and Aspen are recommended to be included within the planting selection
- For reducing soil erosion, water infiltration and for browsing animals and general wildlife enhancements: Oak, Rowan, Wild Cherry, Hawthorne and Hazel would be worth considering in the planting selection.
Further Reading
- Sequestration for Biomass – Farm Carbon Toolkit
- Carbon Sequestration – Farm Carbon Toolkit
- https://www.soilassociation.org/farmers-growers/technicalinformation/agroforestry-handbook/
- Dairy Production – Farm Carbon Toolkit
Useful Resources
- Agricology- shelter belts can protect against soil erosion
- Agricology- trees provide fodder and boost production
- The Woodland Trust- shelter belt tree pack
- Bangor University- shelter belts
- Tree shelter belts for ammonium mitigation