by Paulette Mouchet
Originally published in "The Rose Garden" newsletter, September, 2003.
Cottonseed meal is a popular fertilizer for organic gardens but did you know that cottonseed products run the gamut from cow chow to cold cash?
The cotton plant produces about twice as much seed as it does fiber, and farmers need to save only about 10 percent of the seed for next year's crop. So that's a lot of cottonseed available for other uses. And a lot of uses there are!
There are three components to cottonseed: linters, kernels, and hulls.
Linters, the short fibers that cling to the seed after the cotton fiber is removed, are used in making photographic film, paper money, dynamite, cotton balls, and cellulose products that are found in ice cream, chewing gum, and toothpaste.
The kernel is crushed to produce oil and meal. Cottonseed oil is used in a variety of foods from chips to salad dressings. The oil is also refined into glycerine and soaps. What's left of the kernel is ground into cottonseed meal that is used for animal feed and fertilizer.
Finally, the protective hulls surrounding the kernels are used as roughage in cattle rations and as garden mulch.
As a fertilizer for organic gardens, cottonseed meal has several benefits. The N-P-K is approximately 6-2-1. The nutrients are slowly released and last approximately 4 months. The meal is slightly acidic—a boon to those with alkaline soils and/or water—and it's good source of trace elements. See Chart A below.
Some folks shy away from using cottonseed meal because they've heard that cotton is one of the most highly sprayed crops in the country. This isn't quite true.
According to the California Department of Pesticide Regulation, in 2001, 8.1 million pounds of pesticide active ingredient was applied to 10 million acres of cotton. While that is a staggering amount, how does it compare to other crops? Cotton ranked 8th in pesticide active ingredient applied per acre in 2001.
Because of the potential for pesticide residue, many organic certification programs do not allow the use of cottonseed meal on organic crops and gardens. Both the California Certified Farmers Association and the California Department of Food and Agriculture Organic Materials List restrict the use of cottonseed meal unless it is Certified Organic or is composted, following specific guidelines, before use.
A small but increasing number of farmers are growing Certified Organic cotton. Since 1994, the Sustainable Cotton Project has been helping California farmers switch to organic cotton production. Cottonseed meal from these crops can be Certified Organic and makes a fine fertilizer for the organic rose garden. Whitney Farms offers Certified Organic cottonseed meal fertilizer.
|Cottonseed Meal||Alfalfa Meal|
|Mechanical Extract||Solvent Extract||15% Protein||17% Protein|
|Dry Matter, %||92.3||89.1||90.4||91.8|
|Crude Protein, %||46.1||47.6||15.6||17.4|