00412nam a2200133Ia 4500008004100000082001600041100002600057245007800083260003700161300001000198600002400208600002400232650002200256140113s9999    xx            000 0 und d  a631.6.02 M0  a" Troch, Frederic R."  aSoil and water conservation for productivity and environmental protection  b"New york : Prentice-hall, 1980"  a718p.  a" Hobbs, J. Arthur"  a" Hobbs, J. Arthur"  aSoil conservation