TY - BOOK AU - Troeh,Frederick R AU - Donahue,Roy L AU - Hobbs,Arthur J TI - Soil and water conservation : productivity and environmental protection SN - 0 13 622200 5 U1 - 631.45 PY - 1999/// CY - New Jersey PB - Prentice -Hall KW - Soil erision KW - water erosion ER -