TY - BOOK AU - Troeh,Frederick R. AU - Hobbs,J.Arthur AU - Donahue,Roy Luther TI - Soil and water conservation for productivity and environmental protection SN - 0138221553 U1 - 631.7 22 PY - 1980/// CY - London. PB - Prentice-Hall KW - Soil conservation KW - Water conservation KW - Soil erosion N1 - Includes index ER -