Note: Glossary items marked NOP definition are quoted from the National Organic Program Standards §205.2 ("Terms defined").

C

Calcitic.
Containing calcite, a common crystalline form of calcium carbonate, CaCO₃.

Cations.
Positively charged ions.

Cation exchange capacity (CEC).
The ability of a given soil plot to retain and exchange positively charged ions (cations), expressed in milliequivalents per 100 grams of soil (me/100 g).

Certification or certified.
A determination made by a certifying agent that a production or handling operation is in compliance with the Act and the regulations in this part, which is documented by a certificate of organic operation. (NOP definition)

Certified operation.
A crop or livestock production, wild-crop harvesting or handling operation, or portion of such operation that is certified by an accredited certifying agent as utilizing a system of organic production or handling as described by the Act and the regulations in this part. (NOP definition)

Certifying agent.
Any entity accredited by the Secretary as a certifying agent for the purpose of certifying a production or handling operation as a certified production or handling operation. (NOP definition)

Certifying agent's operation.
All sites, facilities, personnel, and records used by a certifying agent to conduct certification activities under the Act and the regulations in this part. (NOP definition)

Chelating.
Resulting in a chelate and by which process nutrients are held in the soil and made available for plant uptake.

Claims.
Oral, written, implied, or symbolic representations, statements, or advertising or other forms of communication presented to the public or buyers of agricultural products that relate to the organic certification process or the term, "100 percent organic," "organic," or "made with organic (specified ingredients or food group(s))," or, in the case of agricultural products containing less than 70 percent organic ingredients, the term, "organic," on the ingredients panel. (NOP definition)

Colloid, soil.
The particles of soil with a large surface-area-to-mass ratio and generally having a net negative charge, essential to the absorption, holding, and release of ions and thus in the processes of nutrient fixation and uptake.

Commercially available.
The ability to obtain a production input in an appropriate form, quality, or quantity to fulfill an essential function in a system of organic production or handling, as determined by the certifying agent in the course of reviewing the organic plan. (NOP definition)

Commingling.
Physical contact between unpackaged organically produced and nonorganically produced agricultural products during production, processing, transportation, storage or handling, other than during the manufacture of a multiingredient product containing both types of ingredients. (NOP definition)

Compost.
The product of a managed process through which microorganisms break down plant and animal materials into more available forms suitable for application to the soil. Compost must be produced through a process that combines plant and animal materials with an initial C:N ratio of between 25:1 and 40:1. Producers using an in-vessel or static aerated pile system must maintain the composting materials at a temperature between 131°F and 170°F for 3 days. Producers using a windrow system must maintain the composting materials at a temperature between 131°F and 170°F for 15 days, during which time, the materials must be turned a minimum of five times. (NOP definition)

Control.
Any method that reduces or limits damage by populations of pests, weeds, or diseases to levels that do not significantly reduce productivity. (NOP definition)

Crop.
A plant or part of a plant intended to be marketed as an agricultural product or fed to livestock. (NOP definition)
 

Crop residues.
The plant parts remaining in a field after the harvest of a crop, which include stalks, stems, leaves, roots, and weeds. (NOP definition)

Crop rotation.
The practice of alternating the annual crops grown on a specific field in a planned pattern or sequence in successive crop years so that crops of the same species or family are not grown repeatedly without interruption on the same field. Perennial cropping systems employ means such as alley cropping, intercropping, and hedgerows to introduce biological diversity in lieu of crop rotation. (NOP definition)
 

Crop year.
That normal growing season for a crop as determined by the Secretary. (NOP definition)
 

Cultivation.
Digging up or cutting the soil to prepare a seed bed; control weeds; aerate the soil; or work organic matter, crop residues, or fertilizers into the soil. (NOP definition)

Cultural methods.
Methods used to enhance crop health and prevent weed, pest, or disease problems without the use of substances; examples include the selection of appropriate varieties and planting sites; proper timing and density of plantings; irrigation; and extending a growing season by manipulating the microclimate with green houses, cold frames, or wind breaks. (NOP definition)