Encouraging natural biodiversity is an inherent aim of organic farming, not only in the greater environment in which the farm exists, but also in terms of the kind of crops and livestock that are being farmed. Organic farmers often grow unusual varieties of fruits and vegetables that are fast disappearing from our countryside, and they are also more likely to rear traditional breeds of livestock, since these will be best suited to the local conditions.
Variety has all but disappeared from conventional farming, with farmers relying on just a few types of seed and animal, bred specifically to meet their needs - yield and size - and not that of consumers -which is taste. In India, for example, there used to be over 30,000 different varieties of rice, but just ten varieties are expected to cover 75 per cent of the rice-producing land in the next ten years. And in France, the Golden Delicious apple accounts for nearly 75 per cent of all apples grown. In the UK there are 2,300 known varieties of apple but just two - the Cox and the Bramley - now dominate; and of 550 different sorts of pear, three varieties are generally available. Virtually half of Britain's pear orchards and nearly two-thirds of its apple orchards have been destroyed since 1970. These orchards were wildlife havens for many plants and bats, hares, badgers, owls and woodpeckers.
On the livestock front, the world is losing at least two breeds of animal every week. One thousand different breeds of domestic animal have become extinct during the past century and one-third of surviving breeds are endangered, according to the United Nations Food and Agriculture Agency (FAO). They blame this on the success of breeders in the developed world in exporting animals that have been bred to produce more and better meat or milk. The poultry and pig industries are highlighted as being reliant on only a handful of specialized breeds.
The impact on the environment of monoculture or genetic erosion is severe. We are endangering thousands of other species that rely on these plants and animals, losing plants that may well prove of medicinal use in years to come and creating an environment in which disease and pests run rife.
The only way to be sure your food has not been genetically modified (GM) - whereby a gene or genes from one species is inserted into another - is to buy organic food. Worldwide organic standards prevent genetic modification or the use of GM ingredients for many reasons, including the unknown impact of this technology on the environment.
The use of GM seed encourages farmers to depend on a single seed supplier and reduces the chances of a variety of seeds being sown, thereby further threatening natural biodiversity. Even English Nature, the UK government's own wildlife advisor, has called for a moratorium on the growing of these crops. But despite the fact that research concerning the impact of genetic modification on the environment and human health is still pretty thin on the ground, GM crops are already being cultivated and eaten in many places around the world. In the USA, in particular, conventional farmers have greeted genetic modification with enthusiasm and many thousands of acres of land have been dedicated to the cultivation of GM soya and maize. This has led to the widespread introduction of GM ingredients in food production - up to 90 per cent of processed food may already contain GM material.