Problems of land and soil degradation, and their effects on food production, on environmental damages and on natural disasters are increasing worldwide. Besides climate change effects, still nowadays most of the problems are derived of human activities, through land use and management. The use of inappropriate conservation practices, supposedly of universal application, like terracing and no tillage, is also contributing to such increased degradation and derived effects. It has been proved that an adequate evaluation of the land and soil hydrological processes, derived of the interaction of the particular combination of climate, soil and topography, may help to apply precision conservation management practices appropriate for each case. There are presented case studies, using this hydrological approach, under very different climate, soils and land use conditions, in Spain, Colombia, Argentina and Dominican Republic.