The aim is to explore the benefits and challenges of integrating trees into a productive agricultural system at different scales, ranging from forest gardens, to farm-scale agroforestry to landscape scale projects. This session was organised by ORC
Jo Smith (ORC): chair.
The first presentation was by Bethan Stagg of Schumacher College. Bethan presented information about the forest garden system that was established at the college in 2007. These systems are based upon the structure of young woodlands, but are comprised of edible species and are usually up to a couple of acres big. The system at the college consists of plum trees, with a shrub understory and a ground cover of woodland strawberries to help with weed suppression. Whilst the forest garden provides a very diverse source of food and has simpler management and reduced labour compared to more conventional cropping systems, there is a trade-off as yields are reduced relative to other cropping systems at the college.
The next presentation was by Martyn Bragg of Shillingford Organics, who presented details of their farm-scale silvo-horticultural system. The main system combines rows of apples with alleys for vegetable production. They began their first system in 2003, here apple rows are planted 12 m apart with alleys initially containing 5 cultivatable beds of 2m width. This was reduced to 4 beds as the trees have grown and encroached upon the alley. A key benefit of the trees is wind shelter, however this is reduced when trees are not in leaf in late autumn and early spring, so less effective for young growth. Chickens are brought into the rotation in autumn, which helps increase fertility. More recently a new system has been established, with apples interspersed with nitrogen-fixing trees for increased fertility.
Finally, Mike Townsend of the Woodland Trust presented the story of the Pontbren Project, where farmers in Pontbren came together to manage their tree systems on a landscape scale to improve the efficiency of their upland livestock farming. The farmers first came together at the end of the 1990’s, their motivation being the desire to move away from high-input farming. There are now 10 farmers in the group, who farm the whole of the upper catchment area. Initially they realised they required trees for shelter but that they would also provide other benefits. One of these benefits was water infiltration; it has since been shown that water infiltration can be 60 times higher in shelter belts than neighbouring grassland. As a result of their management the canopy cover after 10 years increased from 1.5% to 5%. Productivity has increased in terms of net farm income and efficiency of livestock production.
The discussion that followed the presentations brought out the following points:
- A key area of discussions came in the form of questions about where advice could be sought about such schemes and possibilities for funding.
Individual speaker presentations and abstracts
Bethan Stagg (Schumacher College): Forest gardens – an experiment in horticulture based on woodland complexity
Forest gardens are based on the structure of young natural woodland but with a planting composition of perennial food plants and functional species. Originating in the tropics, they have been adapted for temperate climates in the last two decades, principally through the permaculture movement. We conducted a preliminary productivity assessment of forest gardens compared to organic kitchen gardens (annual vegetables and mixed fruit) at Schumacher College. Yield was substantially lower in forest gardens than kitchen gardens but with proportionately lower labour requirements. Forest garden plots were established in 2007 so yield is anticipated to increase as fruit trees mature. Yield was also subject to the practicalities of perennial greens as food crops and environmental constraints due to locality and design. Challenges with perennial greens relate to seasonal availability, labour associated with harvesting and food preparation. One of the major benefits of forest gardens is ecological and yield stability in variable climates, a consequence of high species diversity. Forest gardens are highly resource extensive, requiring little or no material inputs, as well as minimal labour. Species used as leaf crops in the forest garden are proven to be higher in dietary fibre, macro- and micronutrients than domesticated leaf crops.
Martyn Bragg (Shillingford Organics): Starting an Agroforestry scheme – giving us fruit and nuts to sell and enhancing our production of vegetables
We designed and started planting an Agroforestry scheme in a 10 acre, south facing field last winter and will finish this winter. The avenues are 4.5 metres wide and the cropping area is 24 metres. To the west end there is a thick, tall copse, which gives fabulous shelter and the ‘edge’ area produces fantastic crops. The long term plan is to extend this effect across the whole field. We have designed the scheme very much with our markets and outlets in mind. So we will have a greater range of top fruit (mainly apples,) soft fruit and nuts to sell. At the same time to enhance our production of vegetables in the area between the avenues of trees and shrubs. These avenues will be productive, give shelter and bring in biodiversity. Between the apple trees we planted nitrogen fixing trees. Unfortunately the hot and dry conditions of last summer meant we lost some of these nitrogen fixers. We used ‘tree mats’ but it is definitely better to mulch the whole strip for at least a metre each side of the trees. Once the trees are well established we will remove the mulch and establish a wildflower mix.
The Pontbren Project is an innovative approach using woodland management and tree planting to improve the efficiency of upland livestock farming. In 2001 the Pontbren farmers came together as a group of ten, managing a total of 1000 ha of farmland across the catchment. Over the past 15 years their innovations have been subject to field research on the environmental benefits of trees on farms. Trees and woodlands are now an integral part of farm management in Pontbren demonstrating the benefits for upland livestock farming, water management, wildlife and landscape. The Pontbren project worked because it was led throughout by the farmers who actively took an innovative approach, and who were willing and able to interest and involve others in active collaboration. The undoubted success of Pontbren in agricultural, environmental, scientific and social terms has provided some critical lessons for farmers and policy makers seeking a better way of delivering essential environmental services as part of productive upland livestock farming in the UK.