What Is Organic Agriculture?
According to the National Organic Standards Board (NOSB) of the United States
Department of Agriculture (USDA), organic agriculture is “an ecological production
management system that promotes and enhances biodiversity, biological cycles, and
soil biological activity. It is based on minimal use of off-farm inputs and on
management practices that restore, maintain, or enhance ecological harmony. The
primary goal of organic agriculture is to optimize the health and productivity of interdependent communities of soil life, plants, animals, and people.” (NOSB, 2003)
Though the term “organic” is defined by law, the terms “natural” and “eco-friendly” are not. Labels that contain those terms may imply some organic methods were used in the production of the foodstuff but do not guarantee complete adherence to organic practices as defined by a law. Some products marketed as “natural” may have been produced with synthetic or manufactured products (those not considered to be “organic”), such as “natural beef.” While eco-labels are encouraged for producers
interested in lowering synthetic inputs and farming with ecological principles in mind (biodiversity, soil quality, biological pest control), eco-labels are not
regulated as strictly as USDA organic labels.
The Basis for Organic Farming
The basis for all organic farming systems is the health of the soil.
Organic farmers strive to maintain adequate fertility as well as biologically active soil with the microbial populations required for nutrient cycling. Crop rotation provides nutrients such as nitrogen from legume crops and carbonaceous biomass upon
which beneficial soil microorganisms depend for survival. Naturally mined lime products, manure, and composted manure are the most common forms of soil amendments for organic operations. Iowa rules specify the number of months prior to harvest
that manure should be applied to allow adequate decomposition and to avoid bacterial contamination of produce. Manure cannot be applied for a minimum of four months prior to the harvest of horticultural crops and for three months prior to agronomic crop harvest. Raw manure cannot be applied to frozen or snow-covered ground.
Composting, the preferred method of stabilizing manure, is a controlled process in which nitrogen containing materials are mixed with a carbon-containing source to produce a substance preferably in a carbon-to-nitrogen ratio (C:N) of 30 to 1. Compost temperatures must reach 131–170°F for 15 days, and be turned a minimum of 5
times to aerate the pile. Additional information on composting practices is listed in the references.
Though many soil amendments are available for organic farming, these materials must be naturally based. In addition to manure-based fertilizers, many organic farmers rely on fish emulsion and seaweed preparations to supply nitrogen and other elements. When phosphorus and potassium limit crop production, rock phosphate and naturally mined potassium chloride are allowed. It is imperative that organic farmers check with their certification agencies before applying any materials. Certification may be revoked for up to three years if a material
contaminated with prohibited materials is applied.