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Royal Scottish Forestry Society

Agroforestry – Farming with Trees

 

An integrated approach to land use is crucial if we want to continue to feed ourselves, reduce production costs, improve efficiency and work towards reducing the impact of climate change.  From the time that man domesticated wild animals and developed hand tools, woodlands have been seen as an important resource for shelter, grazing and timber products.  These 3 basic elements have held true for 1000’s of years, but this integrated approach has been lost in the past 60+ years. Why have we lost these skills and what can be done to address the balance?  Do we really understand what Agroforestry is?

 

Farming practice has advanced significantly in the last 60 years – bigger more efficient machinery, less labour, improved crops and livestock and greater productivity from the land, but at what cost?  Field side trees that provided an element of shelter and landscape features have been removed, prime arable land has standing water and flooding issues through an increase in compaction pans, and diffuse pollution from surface water run off continues to cause significant problems.

 

What is Agroforestry

Agroforestry can take many forms, and is perhaps a word not fully understood. or is it possibly the wrong word? Agriculture and Forestry can, and do mesh together, but this is not always appreciated, so perhaps a key to understanding the concept of Agroforestry is to think about what the benefits of trees on a farm are.

  • Many farms have shelterbelts. A shelterbelt provides shelter and warmth to livestock and crops.  A shelterbelt strategically placed can also intercept surface water run-off, help to reduce diffuse pollution issues and protect land below it. A shelterbelt can help to reduce wind borne soil erosion. Timber from a shelterbelt can provide an income and a cheap fuel. A shelterbelt is a form of Agroforestry. There is a benefit from it to the Farmer.
  • Individual trees in fields are often a sign of historic boundaries, others represent older livestock management methods and traditions.  How many people have witnessed livestock under the shade of the tree on hot days, windy days, and cold days? Individual trees are providing benefits, they are a form of Agroforestry.
  • Hedges provide shelter and can also be used to intercept surface water run off – they are a form of Agroforestry
  • Woodlands that are open for grazing are Agroforestry.  In 2013 there was over 21,000 ha of these claimed by farmers in Scotland

 

Farming and Forestry are often regarded as 2 separate land uses with competing  priorities, and as such tension between these exist, however there is probably more integration than we realise. It is the owner of the neighbouring Forest who has the foxes causing the problems and it is the Farmer who has let his stock into the woods.  This tension will always be there but through an educated approach, this could be reduced. During the pre consultation on the new Scottish Rural Development Programme, a recurring theme was that an integrated approach to land use would be of significant benefit, and to consider this further the Woodland Expansion Advisory Group (WEAG) was formed to consider optimal use of land.  One recommendation to come from this was support for Agroforestry measures, (in this instance this relates to wide spaced trees in a field) but with a focus on grazing rather than arable crops.

 

Wider issues

Conducting a review of farming practice and the whole farm approach could identify opportunities for change, such as optimising productivity rather than maximising productivity. What are the true returns on running 1200 high maintenance sheep compared to 800 hardier varieties? Hardier sheep enjoy the  natural shelter provided by trees, and there is an opportunity to potentially increase woodland cover in appropriate places to increase this. High maintenance sheep require housing, supplementary feeds etc . It could therefore be argued that hardier sheep require less input and that when total costs are compared, the returns/head are higher for hardier sheep.  There are also the significant woodland benefits as previously mentioned.

In many parts of Europe and less so in the UK, trees are often grown in combination with crops where ‘alleys’ of crops typically either 12m or 24m in width are managed with a 2-3m wide ‘woodland’ strip between the alleys.  The trees provide shelter, shade, nutrients (from leaf fall) and a second crop to the land. Despite perceptions, the tree roots go very deep so competition for nutrients etc is negligible.  The crops do most of their growth from early spring through to early summer when they effectively start to ripen rather than growing.  From early summer through to late autumn, the trees achieve their maximum growth potential.  What this means is that the area of land has an extended growing season supporting 2 crops.  In Europe it has been shown that where a field of cereals has a value of 1/ha, through the use of trees, the productivity of the land can increase to 1.6/ha.  Early trials in the UK indicate at least a 1.3/ha increase.

 

Possible returns

  • A Farmer outside Peterborough established linear orchards on prime agricultural (class 1) land.  The fruit trees have a dual purpose.  The prime purpose being to reduce wind induced soil erosion that is a significant problem.  The secondary purpose is to produce an alternative crop. Alleys for cereal production are 24m wide (2 passes of a combine harvester) with a 3m ‘tree zone’.  This equates to a 5% loss of arable land on the areas established.  The gross area of orchard is 1 ha, with 1200 fruit trees established.  The fruit production from this site will be about 30 tonnes by about year 7 that will be sold through the farm shop, converted into fruit juice, cider etc.  Farm gate prices for apples in Scotland (for sale to cider producers) are about 30p/kg.  Using this example, the gross return/ha is £9000, significantly more than wheat, but with the benefits of shelter and reduced soil loss.
  • The use of woodlands for shelter/grazing can reduce costs.  By extending the outdoor grazing for cattle by 1 week will save approx £12/head of cattle/week in housing costs.  On a cold day in an open field, if the core temperature of a cow drops by about 2 degrees it will cost about £5/day for supplementary feeding.  Woodlands are generally warmer environments with a warmer micro climate.
  • The majority of farms are not on gas mains and rely on oil for heating.  By installing a log boiler capable of taking 750mm long logs, sourced from their own woodlands, heating costs could reduce by about 75%.

 

Establishment.

            Shelterbelt and woodland establishment is generally straightforward and follows basic principles.  Cultivate the site to ensure that trees planted go into a compaction free environment, protect the trees using individual tree protection, or a livestock exclusion fence, keep the trees weed free and prune side branches on selected trees for quality.

            Establishing wide spaced trees in fields that will provide future long term shelter and shade and allow grazing from the day of planting does require a more robust approach.  The current best advice, is to use 50mm square weldmesh cut from a 900mm high roll to form cages that are 450mm in diameter.  The cages need supported by 2 x75mm fence posts and the tree will also require either a rabbit spiral or vole guard.

 

           

The Future?

            The new Rural Development plan has a number of Forestry options available, but the 2 key ones that will be of interest for farmers will be

  1. Small or Farm woodland – This will be available for those wanting to establish woodlands that are a minimum of 0.25ha in size with a maximum gross accumulated area of 10ha/business.  This option would allow for the creation of well designed shelterbelts
  2. Agroforestry – This will allow for open woodlands to be established with either 200 trees /ha (approximately 7m x7m spacing) or 400 trees/ha (approximately 5m x 5m spacing)
  3. However if you want to plant more than 10ha, then there are other options available

 

If you want to increase the productivity of your land and want more land to farm, don’t rush out and buy land, think in 3 dimensions and look up, not sideways.

 

 

Mike Strachan is the Policy and Development Officer for the Forestry Commission in Perth and Argyll Conservancy.  He is also the current Chair of the UK wide Farm Woodland Forum and the Scotland representative on the European Agroforestry Federation.