_:b670491869 . _:b670491869 . _:b670491869 "An agricultural environmental material which 1) is composed of a mixture of materials such as peat, composted bark, sand, perlite, or compost, and 2) serves as a medium in which to grow plants."@en . _:b670491869 . _:b670491869 . _:b670491869 .