Dr. Earth Compost Starter Mineral Supplement 3 lb. significantly speeds up the decomposition of organic materials to create true organic humus. For use in all types of composting strategies: piles, bins, barrels and others. 100% organic and natural, it contains no GMO's, chicken manure or sewage sludge. It contains Super-active soil and seed inoculant and 5 strains of beneficial soil microbes. TruBiotic® ensures organic nutrients are thoroughly broken down and then released in the soil for plant roots to absorb them as they are needed, contributing to drought tolerance, enhanced nutrient availability and increased plant performance. 0.18 cu ft.