The report, The Biodiversity Benefits of Organic Farming
is the first comprehensive review of nine independent research studies comparing the levels of wildlife between organic and conventional.
Commenting on its contents, Michael Meacher said: ‘There is increasing evidence that pesticides are having significant effects on the environment – and some aspects of intensive agriculture have had a devastating effect on biodiversity.’ He said that organic production should now reach the status of ‘mainstream agriculture’, and roundly concluded that: ‘The report proves that organic farming is good for wildlife.’
Patrick Holden, Director of the Soil Association commented that the UK’s farmland biodiversity is in steep decline and there is an urgent need to identify effective, widely applicable and cost-efficient ways of reversing this trend.
The independent research quoted in this report found substantially greater levels of both abundance and diversity of species on the organic farms, as outlined below:
Plants: Five times as many wild plants in arable fields, 57% more species, and several rare and declining wild arable species found only on organic farms.
Birds: 25% more birds at the field edge, 44% more in-field in autumn/winter; 2.2 times as many breeding skylarks and higher skylark breeding rates.
Invertebrates: 1.6 times as many of the arthropods that comprise bird food; three times as many non-pest butterflies in the crop areas; one to five times as many spider numbers and one to two times as many spider species.
Crop pests: Significant decrease in aphid numbers; no change in numbers of pest butterflies.
Distribution of the biodiversity benefits: Though the field boundaries had the highest levels of wildlife, the highest increases were found in the cropped areas of the fields.
Quality of the habitats: Both the field boundary and crop habitats were more favourable on the organic farms. The field boundaries had more trees, larger hedges and no spray drift.
Overall, the report identified many beneficial practices; utilising methods now rarely used in conventional farming that encourage biodiversity: crop rotations with grass leys, mixed spring and autumn sowing, more permanent pasture, no use of or synthetic pesticides and use of green manuring.
The report concludes that as well as these major biodiversity benefits, widespread organic farming could be a cost efficient, secure and straightforward policy option for reversing the overall declines in the UK’s farmland biodiversity.
(DB)
Gundula Azeez, The Biodiversity Benefits of Organic Farming, Soil Association, Bristol House, 40-56 Victoria Steet, Bristol, BS1 6BY, UK, Fax 0117 925 2504, www.soilassociation.org, supported by WWF-UK, £20.00, 40pp.
[This article first appeared in Pesticides News No. 48, June 2000, page 15]