The Biodiversity Benefits of Organic Farming, The Soil Association, May 2000. Reviewed by Angela Ryan
This booklet by the Soil Association (UK) is ideal for promoting organic farming all over the world. It compiles evidence from comparative studies investigating the impact of conventional and organic farming on biodiversity, and demonstrates that biodiversity is greater on organic farms.
Intensive agriculture has caused farmland species to go into decline and some are now seriously endangered. Organic farming could solve Britain's biodiversity crisis. Unlike convention farming, which is virtually unaccountable, organic standards are maintained by certifying bodies, and include special 'conservation' standards. Moreover, widespread adoption of organic standards would greatly reduce the total cost of agriculture in Britain and is the most cost-effective way of reaching government targets.
The body of evidence is compelling. Ten long-term research studies are documented in detail, accounting for the variety of farmlands found in Britain today.
A rare arable flora survey funded by the Northmore Trust and English Nature shows that many of the rare or declining species of once common arable flowers could be conserved through organic farming. A study from Denmark shows that expanding organic farming would have a marked positive impact on the plant, arthropod and consequently bird population of arable land, including those of now scarce species. A MAFF & WWF sponsored study indicates that organic farming supports a greater number of most bird species and more bird numbers overall. In total 25% more birds were found throughout the year at the field boundaries and 44% more in the in-fields areas outside the breeding season.
Another study from southern England, funded by MAFF, WWF, BBSRC and the Agriculture and Food Research Council, found that organically managed fields support significantly more skylark numbers throughout the breeding season than conventionally cropped or grazed land, with about twice as many breeding skylarks recorded. The rate of breeding success was three times higher on organic farms. The results were attributed to the diversity of crops for organic farms combine both winter and spring-sown cereals, providing skylarks with more opportunities for second and third nesting attempts by moving between fields. In addition there is a greater abundance of invertebrate food resulting from the avoidance of pesticides on organic farms. This studied noted that organic farming reverses most of the agricultural trends that appear to have caused the decline in skylark numbers. But the capacity for organic farming to reverse the national decline is dependent on the percentage of total agricultural land that is organic.
Another study looked at spiders, an indicator species for insect diversity, and found one to five times as many spiders and one to twice as many spider species on organic cereal fields compared to conventional fields. Organic crops have substantially more understorey vegetation than conventional crops and the absence of pesticides offers increased food for spiders, resulting in a larger and more complex community that helps to control crop pests. The research from this study suggests that organic farming is low-input agriculture and "can potentially sustain larger and more diverse spider communities than intensive farming systems".
MAFF similarly reviewed the same evidence in a report published in 1998 and the Soil Association included a quote from the MAFF report in this booklet:
"Organic regimes have the greatest benefit for biodiversity at the farm level. [...] Both in terms of their agricultural practices and the extent and management of uncropped land, organic regimes [...] exert a positive effect on the biodiversity of arable land. The effect derives from the lack of synthetic input, the occurrence of post cropping planting practices that benefit several organism groups and the widespread occurrence and sympathetic management of uncropped elements present with in the regime. This combination of agricultural and structural elements is clearly one that can act to enhance the biodiversity of arable land."
The Soil Association explains why organic farms are more beneficial to biodiversity. They rely on different farming practices, based on using natural processes positively, rather than combating negative effects. It is this 'whole farm systems' approach that nurtures the health of crops and livestock by harnessing natural processes instead of using artificial inputs.
This booklet points out that the most important factor determining the preservation of biodiversity is the type of agricultural system supported by government policy.
Economically, organic food is an expanding market that could help resolve the crisis in farming. It would reduce both the UK trade deficit and the enormous costs to the state of the current agricultural system
The government spends over £3 billion every year in supporting agriculture, of which only 3% is spent on the agri-environment, and of that, only 8% on organic farming (£6.2m). A simple calculation indicates that converting the whole of the UK agricultural area to organic (18,600,000 ha) would cost about £1.2 billion a year, over five years. In comparison, £3 billion is already being spent on directly supporting the current agricultural system together with £2.3 billion or £208/ha that is being spent each year on the indirect costs of conventional agriculture. As organic farmers receive lower subsidies than conventional farmers, about £40/ha less, maintenance payments after conversion could be made at no extra cost.