00488    a2200157   4500082001700000100002100017245009200038260003200130300001700162650004100179650002500220650001700245650001700262650002400279700002700303  a631.451bWIJ  aWijewardene, Ray  aSystems,techniques & tools conservation farmingbfor small farmers in the humid tropics  aColombobMarga publications  av,38p.c29cm  aAgriculture and related technologies  aConservation tillage  aSoil erosion  aSoil science  aSpecific techniques  aWaidyanatha, Parakrama