This study guide is an overview of some key CNG standards that most often trip up newer members. Each rule is first explained in plain language, followed by the standard language, for your reference.
The primary focus is on our Produce & Flower standards, which are fully detailed here.
Manure Application
When applying manure use the 90/120 “manure rule.” Apply* manure more than 120 days before harvest for crops on the soil surface (greens, un-trellised tomatoes, strawberries, etc.) and more than 90 days before harvest for crops not in contact with the soil (trellised tomatoes, corn, apples, etc.). When in doubt, go with 120 days.
*Apply = spread on the field, not leave in a pile!
205.203. Soil fertility and crop nutrient management practice standard
(1) Raw animal manure, which must be composted unless it is:
(i) Applied to land used for a crop not intended for human consumption;
(ii) Incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles; or
(iii) Incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portion does not have direct contact with the soil surface or soil particles;
Composting
If a farmer wants to apply farm-produced compost that includes manure, they better be ready to get their science on! They’ll need to monitor the initial C:N ratio, take temperature readings, and turn the pile often to ensure that their compost is finished properly. If they can’t meet the compost requirements, the compost must be considered raw manure and applied using the 90/120 “manure rule” or applied only to non-produce crops (hay, landscape, pasture, cover crop, etc.).
The same goes for purchased compost. If a compost is not OMRI-listed, CNG farmers may still use it as long as they verify that it was produced according to the compost guidelines and does not contain prohibited additives like biosolids, synthetic fertilizers, or wetting agents.
Compost tea made with finished compost or vermicompost may be applied foliarly or to the soil at any rate and time. Compost tea with additives (fish emulsion, kelp, molasses, etc.) may only be applied using the 90/120 rule, unless tea containing additives is applied within an hour of the additives being mixed in.
205.203. Soil fertility and crop nutrient management practice standard (continued)
(2) Composted plant and animal materials produced through a process that
(i) established an initial C:N ratio of between 25:1 and 40:1; and
(ii) maintained a temperature of between 131 F and 170 F for 3 days using an in-vessel or static aerated pile system; or (iii) maintained a temperature of between 131F and 170F for 15 days using a windrow composting system, during which period, the materials must be turned a minimum of five times.
Seed Sourcing
CNG farmers must use organic/CNG seeds unless they are unable to find the particular variety they wish to grow (or an equivalent variety), in the amount they need, after checking with at least three seed companies that regularly supply organic seeds. This standard applies to regular seeds, plus seed potatoes, sweet potato slips, day-neutral strawberry slips, and some flower bulbs (only if planted and harvested in the same year).
What about seed saving? Farmers are totally encouraged to save their own seed! If they’re new to CNG and hoping to use seed saved in previous seasons, just verify that they’ve been growing their seed without prohibited inputs.
205.204. Seeds and planting stock practice standard
(a) The producer must use Certified Naturally Grown or organically produced seeds, annual seedlings, and planting stock: Except, That, (1) Non-CNG or non-organically produced, untreated seeds and planting stock may be used to produce an CNG crop when an equivalent naturally grown variety is not commercially available, Except, that, organically produced or Certified Naturally Grown seed must be used for the production of edible sprouts;
Seed Treatments
Many treated seeds are not allowed. If you want to use treated seeds, be sure the treatment is compliant with CNG or organic standards.
205.204. Seeds and planting stock practice standard (continued)
(2) Non-CNG or non-organically produced seeds and planting stock that have been treated with a substance included on the National List of synthetic substances allowed for use in organic crop production may be used to produce a CNG crop when an equivalent organically produced, Certified Naturally Grown, or untreated variety is not commercially available;
Transplants
Annual transplants must be grown according to CNG standards, except in extreme cases when a variance has been given.
Potting mix and all other inputs must be free from prohibited, synthetic ingredients. Be especially careful to check that your potting mix does not contain a synthetic wetting agent or synthetic fertilizers. If the wetting agent is yucca, you’re good to go.
Perennial transplants may be purchased from a conventional supplier if an organic equivalent is not available. However, the perennial transplants must be cultivated according to CNG standards for at least one year before the crop can be sold as CNG. So, if you plant conventional raspberry plants this spring, you can’t sell them as CNG raspberries until next spring.
205.204. Seeds and planting stock practice standard (continued)
(3) Non-CNG annual seedlings may be used to produce a crop when a temporary variance has been granted in accordance with 205.290(a)(2); (these variances given primarily because of an extreme natural disaster)
(4) Non-CNG or non-organically produced planting stock to be used to produce a perennial crop may be sold, labeled, or represented as Certified Naturally Grown only after the planting stock has been maintained under a system of CNG management for a period of no less than 1 year; and
Buffers
CNG typically requires buffer zones of at least 20 feet between growing areas and sources of potential contamination. Growing areas adjacent to a high risk source of contamination (e.g. conventional orchard) should maintain a buffer zone of at least 100 feet. The distance required may vary depending on factors such as prevailing wind, topography, and intervening barriers. The adjacent conventional producer’s crop, products, spray height, and spray method must also be considered. Physical barriers and hedgerows are encouraged.
The CNG certification specialist will help you determine the appropriate buffer based on your unique situation.
205.202. Land requirements
Any field or farm parcel from which harvested crops are intended to be sold, labeled, or represented as "Certified Naturally Grown" must:...(c) Have distinct, defined boundaries and buffer zones such as runoff diversions to prevent the unintended application of a prohibited substance to the crop or contact with a prohibited substance applied to adjoining land that is not under CNG management.
*The Produce Inspection form has additional specifics about soil testing.*
Mixed Operations
Mixed operations are farms that have a mix of conventional and CNG field areas. Farmers must ensure acceptable pre-use cleaning of equipment, and properly sized buffer strips to eliminate any chance of chemical contamination between CNG and conventionally grown crops. Farmers must show inspectors that facilities and methods exist to keep conventional and CNG crops separate. CNG will NOT certify farmers who grow a mix of the SAME crop conventionally and CNG in the same year. Crops must be carefully labeled to ensure that customers understand which crops are CNG and which are not.
Additional Produce Standards II: Farmers must ensure acceptable pre-use cleaning of equipment, and properly sized buffer strips to eliminate any chance of chemical contamination between Certified Naturally Grown and Conventionally grown crops. Farmers must show inspectors that facilities and methods exist to keep conventional and Certified Naturally Grown labeled crops separate.Most importantly and most limiting, we will NOT Certify farmers who grow a mix of the SAME crop conventionally and Certified Naturally Grown in the same year.
Inputs
If cultural methods are insufficient, only organically approved substances may be used to manage pests, weeds, and/or disease. If the substance as a whole is not OMRI or CNG listed, each ingredient must be individually checked to determine compliance.
205.206. Crop pest, weed, and disease management practice standard
(e) When the practices provided for in paragraphs (a) through (d) of this section are insufficient to prevent or control crop pests, weeds, and diseases, a biological or botanical substance or a substance included on the National List of synthetic substances allowed for use in organic crop production may be applied to prevent, suppress, or control pests, weeds, or diseases: Provided, That, the conditions for using the substance are documented by the farmer.
Determining if an Input is Allowed
In order to determine if an input is allowed for use in your CNG operation, go through the following steps.
Micronutrients
Synthetic micronutrients may only be used for fertility, they must be OMRI-listed, and there must be a documented deficiency in the form of a soil or tissue test. Remember to ask:
Is this micronutrient…
Therefore, even if a producer is using an OMRI-listed synthetic micronutrient they must ALSO document the need for the deficiency in order to use the product.
This applies to the following nutrients:
Fertility and Soil Amendments – Restricted
Synthetic micronutrients – use is permitted if there is a documented deficiency. NOTE: Micronutrients— may only be used for fertility, and there must be a documented deficiency in the form of a soil or tissue test. Micronutrients made from nitrates or chlorides are prohibited. *See: Allowed and Prohibited Substances
Mulch
CNG encourages use of mulches to control weeds, but certain types of mulches are restricted or have additional management requirements. Polyfilm mulch is allowed, but must be removed at the end of each growing season. Biofilms are also allowed, but there are recommendations regarding their use. Using biofilms in the same growing areas for multiple, consecutive years is strongly discouraged and must be discontinued if the degradation rate seems low. Woven landscape fabric is allowed and does not need to be removed at the end of each season, but must be removed once it begins to break down.
Crop pest, weed, and disease management practice standard. ( 205.206)
(c) Weed problems may be controlled through the following methods:
(1) Mulching with natural or paper-based fully biodegradable materials;
(6) Woven landscape fabric, provided it's removed before degradation;
(7) Polyethylene mulches, provided that they are removed at the end of the growing or harvest season; or
(8) Biodegradable plastic mulch film, or biofilms, with the following restrictions:
(i) CNG producers must register their use of biofilm and provide feedback to CNG when requested at the end of the growing season.
(ii) Oxo-degradable and photodegradable plastic mulch films are prohibited.
(iii) Repeated use of biofilm in the same location for multiple years in succession is strongly discouraged.
(iv) CNG may prohibit continued use of biofilm on particular property if the degradation rate appears low, according to CNG's best judgment informed by consultation with inspector.
Treated wood
Treated wood isn't allowed for new construction where it will come into contact with the soil, though existing wood can be grandfathered in. If you're looking for alternatives, you might consider naturally rot-resistant wood, such as cedar, black locust, black walnut, or white oak; materials like concrete, plastic or steel; or wood-plastic composites, as long as they do not contain fungicides.
(205.206)(f) The producer must not use lumber treated with arsenate or other prohibited materials for new installations or replacement purposes in contact with soil or livestock.
Soil Testing
CNG highly recommends but does not require annual soil testing. A farmer must maintain or improve the soil organic matter content, but the standards do not specify how this is measured. However if a farmer wishes to amend with a restricted synthetic micronutrient they will need to show a deficiency on a soil or tissue sample.
205.203. Soil fertility and crop nutrient management practice standard
(c) The producer must manage plant and animal materials to maintain or improve soil organic matter content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances.
*The Produce Inspection form has additional specifics about soil testing.*
Livestock
Feed for CNG livestock must be produced according to CNG standards. This means that a CNG livestock operation may rely on certified organic feed, transitional organic feed, or feed from a local producer who will sign a Feed Declaration verifying their feed meets the following standards:
CNG encourages the use of vaccines, because they often mean that medications (and/or culling) is not necessary later on. Products from animals treated with ivermectin/ivomec (dewormer), antibiotics, or other conventional medications cannot be marketed as CNG. However, the standards require that appropriate veterinary treatment (including conventional medications) should be given to prevent animal suffering and death. The animal treated just can’t be marketed as CNG and should be sold off-farm to prevent any possibility of mix up.
*Allowed and Prohibited Inputs
Microgreens
Microgreen growers must follow CNG produce standards, but must pay even more attention to sanitation. Just like the potting mix standard, growing media and all other inputs must be free from prohibited, synthetic ingredients. Growers must make extra sure that the media is free of synthetic wetting agents or synthetic fertilizers. If the wetting agent is yucca, they’re good to go!
Sprout growers must follow additional standards, as the food safety risks are high. All seeds for sprouts MUST be certified organic or CNG certified, no exceptions. A yearly water test is also required for CNG sprouts production.
*Microgreens Supplemental Inspection Form
Flowers
CNG flower farmers must follow CNG produce standards, but there are a few considerations made especially for flower growers.