Organic agriculture is a system that sustains the health of soils, ecosystems and people. Organic farmers do not use synthetic pesticides or fertilizers, but instead rely on natural inputs and methods.
Organic growers build soil organic matter with cover crops, compost, and other biological soil amendments. Organic matter in the soil contributes to good soil structure and water-holding capacity and nourishes microbes in the soil that release, transform, and transfer nutrients. Ground rock powders contribute minerals.
Cover crops and crop rotation are used to disrupt the habitat for weeds, insects, and disease organisms. Weeds are also controlled by mechanical tilling, hand weeding, mulching, and flame weeding. Organic farmers rely on soil organisms, beneficial insects, and birds to keep pests in check.
These methods produce healthy plants that are better able to resist disease and insect predation. When pest populations get out of balance, growers use a variety of strategies such as insect predators, mating disruption, traps and barriers. As a last resort, botanical or other natural pesticides may be used.
All products sold as organic must be certified. To be certified as organic in the US, crops must be grown and processed according to standards and verified by state or private organizations that are accredited by the USDA National Organic Standards Board (NOSB). NOSB standards are based on the standards set by the International Federation of Organic Agriculture Movements (IFOAM). Other countries have similar certification processes.
In addition to prohibiting the use of chemical fertilizers and pesticides, organic standards prohibit the use of irradiation, sewage sludge, and genetically modified organisms (GMOs).
Not all farms that use organic methods are certified organic because certification is expensive and it is time consuming to demonstrate compliance. Some farmers prefer to keep costs lower while still producing organic crops.
Because of the increasing popularity of organic products, they are now being produced in large commercial operations. These conform to organic standards, but have been criticized for not truly following organic principles. For example, they may forgo more labor-intensive botanical pest control methods in favor of extensive spraying with organic pest control sprays.