Abstract
Land use planning is routinely presented as the principal instrument through which societies can protect soil and water resources, yet the evidence connecting planning practice to measurable resource outcomes remains uneven and, in several respects, contested. This review examines the state of knowledge on sustainable land use planning for soil and water conservation in rural and peri-urban landscapes, spanning plot, catchment and regional scales. Literature was identified through open scholarly databases and indexes, supplemented by citation searching and by documents from recognised intergovernmental bodies, and was appraised for design quality, transparency of assumptions, and the strength of the inferential link between planning intervention and resource outcome. Four findings structure the synthesis. First, the quantitative basis for defining the planning problem is weaker than its frequent presentation suggests: global and continental erosion assessments rest on empirical models whose validation, resolution and error propagation remain openly disputed, and the disagreement is substantive rather than semantic. Second, evidence on the effectiveness of individual conservation measures is comparatively strong at plot scale but attenuates sharply when aggregated to catchments, because sediment and water connectivity, measure placement, and maintenance regimes govern outcomes that plot experiments cannot capture. Third, interventions that protect soil frequently impose hydrological costs, notably where large-scale revegetation reduces water yield in water-limited settings, so that soil and water objectives cannot be assumed to be jointly satisfiable. Fourth, the persistent shortfall between plans and outcomes is driven less by analytical deficiency than by tenure, incentive structure, administrative fragmentation and rebound effects. Confidence is highest for the direction of plot-scale conservation effects and lowest for catchment-scale attribution, long-term durability and distributional consequences. Priorities include catchment-scale counterfactual designs, routine reporting of water as well as soil endpoints, longitudinal evaluation of measure maintenance, and transparent uncertainty communication in the models on which planning decisions increasingly depend.