Avid gardeners who gravitate toward the organic side of gardening often keep compost piles to make fertilizer. Crab shells are among the items that can be used to create compost. Crab shells have nutrients that encourage soil health.
The crab shells feed the microorganisms found in soil. The protein, chitin, is a key nutritional element found in crab shells. Chitin functions like bone meal in soil.
Crab shells can be combined with other organic materials such as paper, popcorn, bird cage cleanings and egg shells to make compost. Professional organic fertilizer manufacturers dry crab shells in a kiln and then ground them up into crab meal. This crab meal is a key ingredient in some organic fertilizers. (See Resources for how to start a compost pile)
Crush the crab shells up into small bits to prepare them for the compost pile. Add the crushed shells to compost pile so that they can decompose over the winter season.