This University of California Sustainable Agriculture Research and Education Program provides several links to articles on earthworms. These describe the earthworm's importance to ecosystems and agriculture.

This organization promotes sustainable agriculture. Their website provides publications on production practices, alternative crop and livestock enterprises, innovative marketing, and organic certification, and...

The Land Institute is devoted to researching sustainable agriculture. This site contains archives of present and past research activities along with down-loadable publications for use by scientists or the general...

This publication describes research, sponsored by the Land Institute, that compares energy subsidies to energy outputs (including food production) ratios of conventional agriculture and low-energy agriculture.