Maintenance of soil fertility is critical to sustainability of the food supply – crop rotation, fallowing and organic amendment, strict pollution management, and integration of the farming system into the local environment are all components of any well-managed agricultural system. Organic producers are not unique in practicing these, but organic farmers have strict standards under which they are required to practice, which usually means a more reliable outcome for these quality values.
Organic farmers can use a variety of management practices to conserve nutrients and enhance soil quality, including:
- Applications of composted animal manure and other organic residue to form a more uniform and chemically stable fertiliser material. The use of animal manure completes the nutrient cycle allowing for a return of energy and fertiliser nutrients to the soil.
- Use of crop rotations to help trap and recycle nutrients in the soil profile, increase soil tilth, and provide a diversity of crop residues. Crop rotation is an essential component of any organic farming system, creating diversity in space and time that disrupts the growth and development of weed, pest and disease populations.
- Use of green manures and cover cropping is a standard practice in organic farming. Which crops are chosen depends on the intended function of the crop.
- Use of compost is beneficial because it contains antibiotics and antagonists to soil pests allowing for increased plant resistance to attacks, increases crop yields, is important in weed control and builds up soil organic matter.
- Use of annual soil tests to help calculate appropriate amounts of organic fertilisers to add.
- Avoidance of surface application of manure prior to rain, or irrigation.
- Use of farming practices that enhance soil quality and reduce the potential for water runoff and wind and water erosion eg controlled traffic.
- Use of vegetative buffers or filters between cropping areas and water bodies to protect against nutrient and sediment movement into rivers or lakes.