Agroforestry: A unique pathway to securing a more sustainable future
Published 20/02/2013 | 06:00
The term 'agroforestry' is one of the newest buzzwords circulating in the organic sector at the moment. It is an integrated land use system that combines elements of agriculture and forestry in a sustainable production system.
It could be said that Irish farms already incorporate a certain amount of agroforestry, with plenty of hedgerows that have a practical function as field and farm boundaries.
However, the practice of agroforestry is not simply having trees or woodland on the farm. It differentiates itself as a farming system because trees are grown as a specific crop for harvesting, in addition to, and in close proximity to, tillage crops or livestock.
The various farming activities are carried on in "alleys" between the trees.
Farming systems involving crops with fruit and nut trees (silvoarable), as well as trees with pasture/livestock (silvopastoral) were once popular across large areas in central Europe.
Although the practice has decreased significantly over the past 100 years, agroforestry is now making a comeback.
Many EU countries are now beginning to realise the benefits of agroforestry systems.
These systems don't compromise farm production but yet contain quantifiable environmental attributes.
Agroforestry systems harness the effectiveness of trees to deliver conservation of critical resources – namely soil, nutrients, water and biodiversity – while at the same time reducing the need for external inputs that are fossil fuel dependent.
Where agroforestry is practised, there is a significant reduction in nitrogen leaching as trees capture the nitrogen not used by crops.
Research in France shows that this can mean up to 50pc less nitrogen lost under agroforestry systems as opposed to arable systems.
Research from the Organic Research Centre at Elm Farm, Berkshire, England, has shown that the deeper-rooting tree component of an agroforestry system will be able to intercept nutrients leached out of the crop-rooting zone.
This reduces pollution and, by recycling nutrients as leaf litter and root decomposition, increases nutrient use efficiencies.
Agroforestry systems sequester large amounts of carbon from the atmosphere because the trees lock in carbon in the soil. The trees also help waterlogged land to drain more quickly.
Agroforestry systems are beneficial for biodiversity on farms. Predatory insects found in the agroforestry ecosytem have been shown to help with biological control of aphids in wheat.
In agroforestry systems that contain livestock, such as poultry, there are also reports of reduced feather pecking, as well as an impact on production, with a reduced percentage of egg seconds and lower mortality rates.
Sheep and pigs also experience better welfare conditions in agroforestry systems.
Roger Hitchings from the Organic Research Centre will speak at the OGI (see www.iofga.org) conference on February 20 about the Wakelyns Agroforestry project in Suffolk, England.