LUNDENS’ FARM ast of Trollhättan is run by Anders Lunneryd with wife and son, and has been in the family since 1942. Since 1999, the 270 hectares has been KRAV certified; no chemical pesticides or artificial fertilizers may be used. “The instructions of the pesticides urged me to protect myself with a mask and gloves”, Anders recalls. “But hares and other animals in my fields had no advance warning to cover or hide”.
For long he pondered using trees in the field to diversify the production and to increase agricultural resilience; trees that could photosynthesise even after the cereals had ripened and serve as habitat for birds and insects.
The 14 hectares silvo-arable agroforestry/alley cropping system was established by Anders and his son Sven in 2020 on a cereal field, with 38 different varieties of apples, grafted on MM.111 semi-dwarf rootstocks. The apple trees are expected to get 4-5 meters high and the plan is to prune them. The trees have so far been heavily watered. When newly planted, the apple trees had a hard time caused by desiccation, due to wind. Moreover, the spring of 2023 was very hot and dry, and the trees became stressed and got pests such as aphids and codling moths. So far, the ground under the trees is kept clear of vegetation to prevent voles from thriving. When the trees have become more settled, the intention is to plant other vegetation underneath, although it has not yet been decided what.
NATIVE SPECIES SOURCED LOCALLY
Within agroforestry, the basic idea is to mimic the complexity of a living ecosystem to obtain a self-sustaining food production system. If oversimplifying this functional “architecture”, we risk a monoculture, or an organic orchard design that limits the benefits of agroforestry. Agroforestry systems are defined by multiple layers and a structural-, species-, and age diversity, to make the system more resilient, and this should also apply in an alley cropping system.Within the group we discussed the Miyawaki (Tiny Forest) afforestation method, used to restore degraded land on different scales, and its suitability also when planting hedges or treelines in agroforestry. The method mimics natural succession by densely planting a high level of native trees sourced locally, with as broad a genetic pool in plant individuals as possible, to speed up the mycorrhiza collaborations needed to rebuild soil microbiomes. When established, it can improve the stress tolerance and survival among interplanted, more sensible trees.
“Before introducing sensible trees such as walnuts or sweet chestnuts in the system, we ought to mimic natural succession; start with letting in pioneers; wind travellers such as willow, alder, birch and poplar who prefer sun and bare soils. When they’ve established, welcome in the midsuccession, semi-shade tolerant trees such as hawthorn, elderberry and bird cherry; bird travellers who accept both bacteria and fungi dominated soils. Finally let in sensible trees and climax trees that depend on mycorrhiza collaborations, naturally coming in with mammals and bigger birds” - Wouter van Eck, Ketelbroek food forest, the Netherlands.
In Sweden we only have about 40 native tree species, but they form the backbone of the country’s biodiversity, and thus it’s crucial to integrate them, we believe, in agroforestry systems, and if needed to keep them low by coppicing and pollarding.
A variety of trees such as oak, bird cherry, willow, linden, maple and rowan would attract insects and birds at the right time, and in return give an efficient, integrated pest management. Introducing plants typical of species-rich forest edges, such as blackthorn, European hornbeam, sycamore, hawthorn, mountain ash and Swedish Whitebeam would also benefit biodiversity, especially as they rarely occur in plantation forestry, we figured.
We also mentioned the unfortunate fact that shrubs are not eligible for “tree farming” subsidies according to current Swedish regulations. Many shrubs such as alder, sea buckthorn, mountain currant, aronia, sloe, goat willow and other salix species would be optional in a Nordic adapted alley cropping system, being easy to propagate from cuttings and providing many ecosystem services without shading out annual crops.
A WELL ROOTED SOIL
A greater variety of root structures contributes as well more effectively to loosening the soil, to improving the top soil, and strengthening the soil micro-life. The complexity of root structures is also crucial for the efficiency of the mycorrhiza, the fungal network that receives part of the plants’ excess energy and in return connects the roots of different plants in large networks, enabling communication and exchange of nutrients from larger soil surfaces and depths.
The system has 20 metres wide alleys, a distance that is adapted to the farm’s 8 metre wide seed drill ,and 4 metre wide refuges. The optimal scenario is if the root system reached all the way underneath the alleys, connecting the whole field. Chemical pesticides and fertilizers used for the annual crops would cause damage to these underground fungal threads.
SPREAD OUT DIVERSITY
Furthermore, by spreading out the apple varieties, the rates of apple scab have proven to be reduced, according to measurement between apples in organic orchards and apples in the Wakelyns Agroforestry system in England:
”In each hedge we have 8 species of apple, 2 of each, randomly spread out in the tree lines. This makes it more difficult for the pathogen to spread…”
- Professor Martin Wolfe, pioneer of organic agriculture, cited in the film “
“Life within planetary boundaries - Agroforestry“
However, this may complicate a “rational” harvest. Allowing some apples to become food for animals, might be a practical option. In discussions among the participants, halt pruning the apple trees was also suggested.Lundens’ grow spelt, rye, ein-korn wheat, emmer and “Lunden wheat” with large genetic diversity in the mix, making it harder for pathogens to spread. As well as rapeseed, fava bean and grey peas, which has a thousand-year history of cultivation in Sweden. As the grains at Lundens’ farm require nitrogen fertilizer from circulated waste products, the group argued this could be replaced by nitrogen-fixing plants such as Sea buckthorn or common/black alder, making the system less dependent on industrial, linear economy.
A more diverse and dense system does not only more efficiently prevent run-off. For example, the spread of wind borne diseases in annual crops have also shown to be reduced by tree barriers. To avoid such a system becoming too dense, it needs to be pollarded. The residues left on the ground would improve the soil.
“Photosynthesis creates precipitation as it cools the immediate area around the leaves - hence we can plant water” - James Godfrey Faussett, forest advisor, Miyawaki forest and nature restoration expert.
Along the fence, trellised B9 rootstock apple trees are planted. The group discussed the advantages of planting a surrounding poplar windbreak, or a temporary windbreak from fast-growing, soil-loosening, fertilizing and pollinator attracting industrial hemp, as it needs much less water than conventional crops, reduces drought caused by the wind, and make work easier for pollinators and other insects who easily become exhausted by the wind.
The group also noted that autumn sowing might be the most suitable for this kind of system, now used for spring sowed cereals, as the trees would not leaf out in time to shade out the crop before spring harvest. With no road along the tree lines this is not an option, as it would result in the sowing being destroyed when driving along to pick the apples.
The largest cost in establishing the system was 16.600 Euro for fencing, to keep out deer. As the income from apples is modest, the group discussed considering giving up fences in a system like this, and to expect some loss through deer damage. The money saved could be used for building a farm nursery, for diversification.
Since 2024 planting trees to produce food, feed or other ecosystem services in combination with annual crops on arable land is eligible for subsidies in Sweden. The trees may not cover more than 50 percent of the total area of the block/field. Nurse trees are accepted, and may be moved into the system, but can not be brought in by birds. As agroforestry doesn’t entail a static system, but one in constant life- and management cycles in interaction with surrounding nature, it’s not fully clear how the rules will apply.