The Common Ground Country Fair marks its 50th year as it launches Friday in Unity.

The three-day-event features more than 1,000 exhibitors and speakers, highlighting organic agriculture and sustainable rural living.

Keynote speakers this year include Philip Gregory, a litigator with Our Children’s Trust, and youth plaintiff Avery McRae, who will explore on Friday whether the government has a duty to safeguard the climate for future generations.

On Saturday, author, advocate, and Executive Director of Global Alliance for the Future of Food Anna Lappé explores the “four freedoms of food,” while authors and community organizers Annie Leonard and André Carothers will talk about the power of nonviolent protest.

Presentations and workshops all weekend at Common Ground cover farming and gardening; sustainability skills and forestry; and livestock, fleece and fiber. Food is available for purchase from more than 40 vendors, and the event also features farmers’ markets, live music, border collie livestock herding and children’s activities.

The fair is organized by the Maine Organic Farmers and Gardeners Association. For more details on the full event schedule and ticketing information, visit www.mofga.org.