Cottonseed meal is widely available as a fertilizer and soil conditioner, but it comes with some problems, according to an article by Alex Owre in The Maine Organic Farmer &Gardener. Cottonseed meal may not be allowed in organic production because cotton is heavily sprayed with pesticides, and it’s hard to know if the meal contains residues. Also, much cotton is now genetically engineered to express the Bacillus thuringiensis toxin in all parts of the plant — another reason the meal is not welcome in organic production unless the source and safety can be documented.
    Cottonseed meal is not a good value for the money, either, Owre writes. A 4-pound bag costs about $6 and contains 0.24 pounds of nitrogen, or about $25 per pound of N. For comparison, alfalfa meal costs $46 per pound of N; blood meal, $12; soybean meal, $17. Hairy vetch, on the other hand, can be grown as a cover crop that can fix more than 100 pounds of N per acre, a cost of 13 cents per pound of N.
    “Growing your own nitrogen adds lots of organic matter to the soil as well; protects the soil from erosion; helps keep existing nutrients from leaching; has less environmental impact than buying N from any off-farm source; and supports a diverse ecology in the garden,” the article says.
(The Maine Organic Farmer & Gardener, September-November 2007, www.mofga.org)