I do not have an immediate answer to your question. But, we are in a program to promote collaboration among college teachers and students of undergraduate colleges in India for doing research as a means of better learning process. Simple model systems based collaborative research addressing sophisticated questions in biology is our approach. Earthworm obviously is one of the candidate model systems.
We would like you to join us.
We operate from the Homi Bhabha Center for Science Education (HBCSE), TIFR, Mumbai though, are keen to establish hubs across the country to reach out to more than 20,000 colleges in the country..
Please see this link, an article in the Times of India, for an introduction to the program, called CUBE (Collaborative Undergraduate Biology Education):http://epaper.timesofindia.com/Default/Scripting/ArticleWin.asp?From=Archive&Source=Page&Skin=TOINEW&BaseHref=TOIPU%2F2013%2F10%2F17&ViewMode=GIF&PageLabel=6&EntityId=Ar00600&AppName=1
Perhaps earthworms, in processing earth, might help sequester carbon into carbonate rock, formed from oxide rocks. Ultramafic and alkaline rock dusts, from mantle rock, might nourish worms with minerals while binding carbon dioxide. Ultrapotassic rock dust might, after being processed by earthworms, make potassium available to crops. Please see: https://www.see.ed.ac.uk/~shs/Climate%20change/Carbon%20sequestration/oliv2-1.pdf