유기농업이 생물다양성에 이롭다

Organic farming is the best way of reversing the decline in wildlife. Organic farming actually depends on encouraging a diverse ecosystem to maintain soil fertility and to keep pests under control naturally. Important organic farming practices include:

• Encouraging natural predators by maintaining hedgerows and creating open spaces at side of fields
• Mixed farming where different crops are planted together
• Changing the crops planted each season, to keep soil fertile and avoid the need for chemicals

The Soil Association knows that because so many organic farming practices are wildlife-friendly implementing organic farming on a wide scale would reverse this decline.

As well as the Soil Association’s own biodiversity research, a number of organisations have looked at the links between farming and wildlife:

• A 2005 scientific literature review by English Nature and Royal Society for the Protection of Birds (RSPB) found that there are more birds, butterflies, beetles, bats and wild flowers on organic farms than on conventional farms. This is because the farm as a whole is subject to environmental standards, rather than just limited areas - which occur under agri-environment schemes on non organic farms.
• A literature review of 66 published comparative studies concluded that on average wildlife is 50% more abundant on organic farms and there are 30% more species than on non-organic farms. ('The effects of organic agriculture on biodiversity and abundance: a meta-analysis', by Swedish researchers (Bengtsson, Ahnström and Weibull), published in the Journal of Applied Ecology, 2005)
• An extensive survey by the British Trust of Ornithology in 2005 of lowland mixed crop and livestock organic farms in England found that organic farms have almost twice as many numbers and species of plants, about a third more birds and a third more bats than non-organic farms. The researchers believe that the potential of organic farms to support wild animals is actually far greater than this, and that biodiversity benefits are held back because organic farms are currently mostly 'isolated units' in an intensively managed landscape.

The main benefits of organic farming for biodiversity are its non-use of fertilisers, herbicides and synthetic wormers; minimal use of pesticides; lower livestock stocking densities; encouragement of natural predators for controlling pests (and thus maintenance of hedges, field margins and other uncropped areas); higher soil biological activity; mixed crop and livestock systems rather than monoculture. It is the absence of these beneficial factors on most non-organic farms that has accounted for most of the decline in wildlife in Britain's farmed countryside in recent decades.

Yet, while 76% of the UK's land is used for agricultural purposes only 4% of this is farmed organically. 

policy_report_2000_biodiversity_benefits.pdf

policy_report_2000_biodiversity_benefits.pdf

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