credit: seattletilth.orgSeattle Tilth is offering an intensive four-week seminar, entitled “Become a Master Composter,” in exchange for community service hours. Master composters/soil builders will learn how to compost various organic materials using several approaches, improving soil health, conserving and protecting water quality, avoiding pesticide use, and curbing greenhouse gases. Hands-on classes meet Wednesdays and Saturdays, March 31-April 24, with applications due Feb. 28. More info at 633-0097, grahamgolbuff@seattletilth.org, and seattletilth.org.