Cultivating trees and agricultural crops in combination with one another is an ancient system that farmers have used throughout the world. In Europe, until the Middle Ages, it was the general custom to clear-fell degraded forest, burn the slash, cultivate food crops for varying periods on the cleared area, and plant or sow trees before, along with, or after sowing agricultural crops. This has been practiced in Finland and Germany up to the 1900s. Many tropical crops like coffee, cacao, papaya and squash are still grown like this.
Forest gardening
Edible forest gardening is the art and science of putting plants together in woodland-like patterns that forge mutually beneficial relationships. It can produce fruits, nuts, vegetables, herbs, in a diverse, high-yield garden that is largely seIf-maintaining. One example is in a small garden plot with garden beds, where plants can stand close, get manure and grass clippings, and otherwise be optimally pampered. It can then give much more yield per square meter than when growing in a field with long lines and although possibly with less harvest per invested working hours. The three main products from a forest garden are fruit, nuts and green leafy vegetables. Forest gardening can employ some of the techniques of a no-dig, or synergistic gardening where initially the garden soil is dug thoroughly in a raised bed system, after that the soil is not disturbed deeper than the sowing depth, neither exposing soil to air or compressing it by walking on it which both destroy the natural digestive flora in the soil. Unwanted crops are weeded out, harvested crops are cut at the base and the foliage placed on the soil to compost and mulch naturally.
Features
Agroforestry systems are probably the most self-sustaining and ecologically sound of any agricultural system. As in a natural forest these systems make maximum use of space vertically and horizontally. Every part of the land is considered suitable for useful plants. Emphasis is placed on perennial, multi-purpose crops that are planted once and yield benefits over a long period of time. Traditionally agroforestry systems are managed as a forest gardens. However alley cropping has recently been developed with rows of conventional crops (the width of a combine harvester), such as wheat, between rows of cropping trees, such as walnut.
Benefits
Benefits include construction materials, food for humans and animals, fuels, fibres, and shade. Trees in agroforestry systems also have important uses such as holding the soil against erosion and improving soil fertility (by fixing nitrogen or bringing minerals from deep in the soil and depositing them by leaf-fall. In a system with trees and pasture, with foraging animals, the trees provide shade and/or forage while the animals provide manure.
- Improved year-round production of food and of useful and salable products.
- Improved year-round use of labour and resources.
- Protection and improvement of soil, especially when legumes are included, and water sources.
- Increased efficiency in use of land, especially in several vertical layers.
- Shade for vegetable or other crops that require or tolerate it.
- Medium and long-term production of fruits.
- Long-term production of fuel and timber
Publications
Integration of trees in farming - AGFORWARD www.agforward.eu
An introduction to agroforestry http://www.worldagroforestry.org/Units/Library/Books/PDFs/32_An_introduction_to_agroforestry.pdf?n=161
What is alley cropping? http://nac.unl.edu/documents/workingtrees/infosheets/WT_Info_alley_cropping.pdf
Organisations
Agroforestry Research Trust www.agroforestry.co.uk
Farm Woodland Forum www.agroforestry.ac.uk
The World Agroforestry Centre www.worldagroforestry.org
Videos
Martin Crawford's forest garden
Agroforestry – Alley cropping