The biodiversity benefits of organic farming come under three broad headings:
(i) the enterprise mix (mixed livestock and cropping instead of specialisation; crop rotation instead of mono-culture etc.), (ii) the treatment of the cropped area (the avoidance of agro-chemicals, the less intensive approach etc.), and (iii) the boundary features (field margins, more and larger hedges etc.).
But, what is the origin 6/these benefits?
Organic farming is a particular whole farm "systems" approach. It is often discussed as a collection of different practices, but organic farming is actually the whole package of the approach and all the individual practices.
For a start, organic farming is based on a set of principles, for example:
a holistic approach to farming (instead of addressing problems individually),
the creation and maintenance of conditions that positively nurture the health of the crops/livestock (instead of solely treating the
symptoms of problems, eg. applying chemicals), and
the harnessing of natural processes (instead of relying on artificial inputs).
Thus, for example, agro-chemicals are avoided and instead alternative practices based on these principles are used. Many of these benefit biodiversity. Indeed, many of the agricultural practices of organic farming involve the positive use of biodiversity (through the soil, field margins, hedges etc.), thus making the conservation of biodiversity an integral part of the farming system. For example, the soil is treated as a living entity not simply as a substrate for crops to grow in.
The "standards" for organic farming developed long after organic farming had been established as a system, but are now used as a template and guide for the practice of organic farming. Some practices arc obligatory, others are "recommended". With the latter, many are the most practical organic approach and so are also the standard practice for that issue. In addition, there are special "conservation" standards to ensure that specific conservation objectives are addressed in more detail.
Some of the biodiversity benefits of organic farming can be directly linked to particular standards (eg. avoiding the use of agro-chemicals, the use of grass leys), others are an indirect result of the standards (eg mixed crop and livestock farming, mixed spring and autumn sowing), and yet others are the result of the farmers applying the principles and approach of organic farming in an way tailored to their situation and for issues and to a detail not dealt with by the standards.
Thus, the range, degree and quality of the benefits of organic farming is delivered by the whole package of the approach, not simply bv the standards.