Benefits of Weeds in Farming Systems
Organic farmers and growers should not be aiming to completely eradicate weeds from their fields and farms. Management rather than complete control is a more realistic and desirable goal. The word 'management' emphasises use of appropriate methods to maintain acceptable weed levels that take into account short-term economic and long-term ecological issues.
In spite of all the difficulties caused by weeds, they can offer some beneficial properties, particularly when occurring at low densities. These aspects should be utilised in the farming system, although this may make organic management more complicated than chemical based systems. Some of the potential benefits of weeds are listed below:
- helping to conserve soil moisture and prevent erosion. A ground cover of weeds will reduce the amount of bare soil exposed helping to conserve nutrients, particularly nitrogen which could otherwise be leached away, especially on light soils.
- food and shelter can be provided for natural enemies of pests and even alternative food sources for crop pests. The actual presence of weed cover may be a factor in increasing effectiveness of biological control of pests and reducing pest damage.
- weeds can also be valuable indicators of growing conditions in a field, for example of water levels, compaction and pH.
- weeds can be an important source of food for wildlife, especially birds. Bird populations have been declining on farmland over the last few decades and leaving weeds as a resource has been shown to help revive bird populations.
We have provided more information on some benefits of weeds including: