The USDA organic regulations describe organic agriculture as the application of a set of cultural, biological, and mechanical practices that support the cycling of on-farm resources, promote ecological balance, and conserve biodiversity. These include maintaining or enhancing soil and water quality; conserving wetlands, woodlands, and wildlife; and avoiding use of synthetic fertilizers, sewage sludge, irradiation, and genetic engineering.
Organic producers use natural processes and materials when developing farming systems these contribute to soil, crop and livestock nutrition, pest and weed management,attainment of production goals, and conservation of biological diversity.
Organic Crop Production Practices Soil Fertility: Crops more easily resist disease, survive drought,and tolerate insects when grown in good soil. Organic crop producers build soil quality by adding compost, animal manures,or green manures. As soil organisms break down these inputs, they convert nutrients into forms plants can absorb and create humus that sustains soil quality. Organic producers must not apply sewage sludge or biosolids to soil. Additionally, organic crop producers use cover crops to protect the soil from wind and water erosion. Soil-conserving practices include the use of cover crops, mulches, conservation tillage, contour plowing, and strip cropping.
Seeds and Planting Stock: Organic crop producers use organic seeds and planting stocks to protect the integrity of their crops. Organic growers may use conventionally grown seeds when an equivalent organic variety is not commercially available, but only if the seeds have not been genetically modified or treated with prohibited substances, such as fungicides.
Crop Rotation: Organic crop producers practice crop rotation (rotating the crops they grow in a field or planting bed over time) to interrupt insect life cycles, suppress soil borne plant diseases, prevent soil erosion, build organic matter, fix nitrogen, and increase farm biodiversity. To effectively reduce insect and disease levels, farmers typically follow one crop with another from a different crop family, then wait a number of years before replanting the initial crop. While crop rotation is also practiced by many conventional farmers, organic producers are required to implement the practice by the USDA organic regulations.
Managing Pests, Weeds, and Diseases: Pest management on organic farms relies on the ‘PAMS’ strategy: prevention, avoidance, monitoring and suppression. Prevention and avoidance are the first line of defense against pests, weeds, and diseases. If pest or weed suppression becomes necessary, producers often use mechanical and physical practices, such as releasing predatory insects to reduce pest populations or laying down a thick layer of mulch to smother weeds. As a last resort, producers may work with their organic certifier to use an approved pesticide, such as naturally occurring microorganisms, insecticides naturally derived from plants, or one of a few approved synthetic substances.
Maintaining Identity and Integrity of Organic Crops: Organic crop producers are responsible for preventing contact between organic and conventionally-grown crops, as well as contact with prohibited pesticides or fertilizers. Split operations (farms that raise both organic and conventional crops) must make sure that organic crops don’t contact prohibited substances through accidental sprays of conventional agrochemicals, spray drift, or residues on equipment from non-organic fields.
Source : USDA Organic /AMS