Soil Fertility & Sewage Sludge

By: Margo Beck and Bella Petitta

Soil Fertility

1. The producer must not use any fertilizer or composted plant and animal material that contains a synthetic substance not included on the National List of synthetic substances allowed for use in organic crop production. Except:

Plastic mulch and covers
Papers coated in gloss

However, these non-synthetic substances are not allowed:

(a) Ash from manure burning.
(b) Arsenic.
(c) Calcium chloride, brine process is natural and prohibited for use except as a foliar spray to treat a physiological disorder associated with calcium uptake.
(d) Lead salts.
(e) Potassium chloride—unless derived from a mined source and applied in a manner that minimizes chloride accumulation in the soil.
(f) Rotenone (CAS # 83-79-4).
(g) Sodium fluoaluminate (mined).
(h) Sodium nitrate—unless use is restricted to no more than 20% of the crop's total nitrogen requirement; use in spirulina production is unrestricted until October 21, 2005.
(i) Strychnine.
(j) Tobacco dust (nicotine sulfate).

2. A producer may manage crop nutrients and soil fertility to maintain or improve soil organic matter content in a manner that does not contribute to contamination (altering its pure form) of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances by applying:

Nonsynthetic substances
Mined substances
Ash obtained from the burning of a plant or animal material - Provided, that it was not produced for the sole purpose of being added to the soil. And that the material burned has not been treated or combined with a prohibited substance or the ash is not included on the National List of nonsynthetic substances prohibited for use in organic crop production.

3. 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 (altering its pure form) of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances. Animal and plant materials include:

Processed animal manure, that 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

(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

Composted certified organic plant and animal material
Uncomposted Certified organic plant materials

4.The producer must select and implement tillage and cultivation practices that maintain or improve the physical, chemical, and biological condition of soil and minimize soil erosion. They must consider the effect of their tillage machinery on the compactness of their soil and actively try to limit its effects.

5. The producer must manage crop nutrients and soil fertility through rotations, cover crops, and the application of plant and animal materials that were not obtained for the sole purpose of increasing soil fertility. (For example: One cannot go out of their way to harvest or purchase harvested kelp for their field. Or one must not slaughter animals only to obtain bones to create bone meal.)

6. Consider runoff factor. Do not apply fertilizer when large amounts of precipitation are predicted. If your farm is located near a body of water (creek, stream, river, bay, ocean, etc.), you must use the injection method.

Retrieved from: https://www.epicgardening.com/organic-fertilizers/

Sewage Sludge

Must be class A
The sludge has to be obtained from a processing facility that is closet to your farm location (in order to minimize travel/transportation emissions)
The producer must not use:
- Burning as a means of disposal for crop residues produced on the operation: Except, That, burning may be used to suppress the spread of disease or to stimulate seed germination. (Code of Federal Regulation, 2019)

As defined by EPA, they are:

When properly treated and processed, sewage sludge becomes biosolids which are nutrient-rich organic materials produced from wastewater treatment facilities. (Basic Information about Biosolids, 2017)
Class A sewage sludge may be applied to soil when it is properly processed
Sewage Sludge may not be applied to soft fruit, vegetable crops, or used where crops are grown under glass or plastic structures (Agricultural Use of Sewage Sludge, n.d.)
“Treated sludge can be applied to growing cereal crops without constraint but should not be applied to growing turf within 3 months of harvesting or to fruit trees within 10 months of harvesting. When treated sludge is applied before planting such crops as cereals, grass, fodder, sugar beet, fruit trees, etc., no constraints apply but in the case of soft fruit and vegetables, the treated sludge should not be applied within 10 months of crop harvesting. In general, untreated sludge should only be cultivated or injected into the soil before planting crops but can be injected into growing grass or turf, with the constraints on minimum time to harvesting as already mentioned.” (Agricultural Use of Sewage Sludge, n.d.)

Retreived from: https://image.slidesharecdn.com/sauravhm-160509112946/95/behaviour-of-heavy-metals-in-sewagesludge-amended-soil-4-638.jpg?cb=1462793517

Retrieved from: http://2.bp.blogspot.com/-viI76AHxleg/T1Zb5jQNy-I/AAAAAAAACIM/FoCpsuPNmJg/s1600/fertilizers.jpg

Works Cited

Agricultural Use of Sewage Sludge. (n.d.). Retrieved March 13, 2019, from http://www.fao.org/3/T0551E/t0551e08.htm

Basic Information about Biosolids. (2017, June 20). Retrieved March 13, 2019, from https://www.epa.gov/biosolids/basic-information-about-biosolids

Buob, T., Estes, G. O., Mitchell, J. R., & Seavey, D. (2017, December). Manual of Best Management Practices for Land Application of Biosolids (C. Majewski, Ed.). Retrieved March 13, 2019, from https://extension.unh.edu/resources/files/Resource005011_Rep7148.pdf

Code of Federal Regulations. (n.d.). Retrieved March 13, 2019, from https://www.ecfr.gov/cgi-bin/text-idx?SID=20c3b310255d383bd7419100bafbe549&mc=true&node=se7.3.205_1203&rgn=div8

Sewage Sludge as Fertilizer: Safe? (2010, October 04). Retrieved March 13, 2019, from https://www.foodsafetynews.com/2010/10/sewage-sludge-as-fertilizer-safe/

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