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Home  > Question of the Week

Question of the Week

Permalink Is there a significant difference in nutrient content between composts made with static and aerated systems, and where can I find bacterial inoculants for making compost?


Answer: Compost is an organic amendment that results from microbial decomposition of raw organic matter, followed by humification and buildup into a stable, mature, humus-like end product. The nutrient content of compost can be determined through laboratory analysis. However, nutrient analysis does not account for the nutrients tied up in compost’s microbial biomass or the nutrients released in soils through the biological action of microbes when compost is incorporated into the soil.

Variations in the nutrient content of finished composts is largely affected by the feedstocks used in the compost recipe. For example, composts made from poultry manure will have a higher nutrient content than yard-waste composts. The nutrient content of composts will not differ greatly if the same feedstock ingredients are used. Nitrogen concentration of finished compost ranges from 2% to 3%, on average. With poultry-manure based composts, you may see N analysis as high as 5%.

On the other hand, compost quality results from a managed process of organic matter decomposition and buildup into a humus-like organic amendment. In the static pile method, there is little ability to manage the environmental factors that effect compost quality. The pile can become too dry in the interior and slow down or arrest the composting process. Portions of the pile can become anaerobic and result in putrefaction. In contrast, with a turned and aerated pile —managed with a front-end loader or compost turner — the farmer has the ability to manage for moisture, oxygen, and feedstock mixing.

There are four sources you can look to for further information on this topic.

On-Farm Composting Handbook (NRAES-54) is a 186-page handbook about on-farm composting, published by Natural Resource, Agriculture, and Engineering Service (NRAES). It provides a comprehensive summary of the composting process, composting methods, raw materials, using compost, site and environmental considerations, marketing, economics, and management. It is probably the best all-round publication on this topic published by the Extension Service. The cost is $25, plus shipping and handling.

Field Guide to On-Farm Composting (NRAES-114) is a 119-page field guide to on-farm composting, designed as a handy accompaniment to the On-Farm Composting Handbook. It is spiral-bound, in an 11.5" by 5" format and designed for quick reference. It is filled with charts, tables, figures, data, formulas, calculations, illustrations, and text. The cost is $14, plus shipping and handling.


Cooperative Extension
PO Box 4557
Ithaca, NY 14852-4557
607-254-8770 FAX

Alternative Soil Testing Laboratories is a resource list from the ATTRA National Sustainable Agriculture Information Service. It identifies laboratories that specialize in compost analysis.

Compost Quality Standards is a resource list compiled by the ATTRA National Sustainable Agriculture Information Service. It summarizes some of the compost quality parameters that are used to evaluate and understand compost quality. It also provides a list of Web sites that address this topic.

In the second part, you asked about bacterial inoculants to make compost. Microbial inoculants for compost are available from several suppliers, and a few of these are listed below.

Microbial inoculants are not necessary to make compost, since there are sufficient microbes in the raw feedstocks and surrounding environment. On the other hand, many of the best composters use microbial inoculants to enhance control of odors and to improve compost quality. They can be considered microbial cultures, much the same way microbial cultures are used to make breads, cheeses, and wines.

Sources of Compost Inoculants:

Bountiful Gardens
18001 Shafer Ranch Road
Willits, CA 95490-9626
707-459-1925 FAX

Petrik Laboratories, Inc.
109 Harter Ave
Woodland, CA 95776
530-661-0489 FAX

Midwest Bio-Systems
28933 35-E Street
Tampico, IL 61283
815-438-7028 FAX

Josephine Porter Institute for Applied Biodynamics
P.O. Box 133
Woolwine, VA 24185-0133
276-930-2475 FAX



Permalink Where can I find information about producing and hatching fertilized eggs?


Answer: Producing fertile eggs depends on several factors listed in the chapter “Incubation and brooding” cited below, as well as on the rooster/hen ratio needed to produce fertile eggs. Several of the cited articles and sections from books below deal with fertility issues, handling hatching eggs, and recommended rooster/hen ratios.

Also cited are several articles and chapters from books dealing with natural incubation by the hen and with incubators. These materials provide a good starting point in considering which method will work best for you.

Also see the article "Egg Processing by Hand" that discusses washing and candling eggs. Candling eggs is the best method to check eggs for embryo development. In addition, there are several articles and publications that deal with brooding the chicks after hatching.


Alexander, Daniel. 1996. Making chickens…From chickens. Cognition. Summer. p. 9-11.

Anon. 2001. Incubation, and Using incubation equipment. Nova Scotia Agriculture and Fisheries. 7 p.

Anon. 2004. Success with baby chicks. Norton Creek Press home page. 4 p.

Batty, J. 1990. Number of females. In: Natural Incubation and Rearing. Nimrod Press Ltd. p. 21-23.

Bennett, Dan. 2002. The brooder nightmare. American Pastured Poultry Producers Association Newsletter Grit, Issue #23. p. 8-9.

Ensminger, M. E. 1992. Incubation and brooding. In: Poultry Science. Interstate Publishing, Inc., Danville, Illinois. p. 43-55.

Fanatico, Anne. 2003. Egg processing by hand. American Pastured Poultry Producers Association Newsletter Grit, Issue #26. p. 6-7, 13.

Glos, Karma. 2002. Organic brooder management. Organic Farms, Folks & Foods. Mid-Spring. p. 23-25.

Lyons, Jesse J. 1999. Brooding and growing chicks. University of Missouri-Columbia Extension. G 8351. 4 p.

Sturges, T. W. 1987. Hatching, rearing and selling chickens. In: Poultry Culture for Profit. Nimrod Press, LTD., England. p. 68-75.

Sullenberger, David. 1990. The original incubator: How to hatch chicks the “natural” way. Countryside & Small Stock Journal. July/August. p. 26-28.

Throp, Jack. 1991. Hatching eggs from setting hens. AMBC News. January/February. p. 6-7.

Willard, Christine. 2004. Breeding programs for the home flock. Small Farm Today. January. p. 30-32.



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