On Earth Day, 200 members of  “Occupy the Farm to Take Back the Gill Tract” planted a renegade farm on an empty plot of land called Gill Tract to keep it agriculturally pristine. The plot of land is owned by UC Berkeley, which is planning to build housing and a grocery store on half of the 10 acres. Activists, however, want the entire plot to become an urban ecological farm. Read more about it on SFGate.com.