TROEH, Frederick R. Hobbs, J.Arthur Donahue, Roy L. Soil and water conservation: for productivity and environmental protection / [by] Frederick R.Troeh, J.Arthur Hobbs, Roy L.Donahue - New Jersey Prentice-Hall 1980 - xv, 718 p. Includes appendixes and index. ISBN: 138221553 Subjects--Topical Terms: Soil conservation Dewey Class. No.: 333.72 / TRO