Soil erosion on dry farming land in two changing environments of the central Ebro Valley, Spain

摘要: Abstract Increasing loss of productive soils is a major concern in semiarid areas the Mediterranean region. About 40% Spanish territory seriously affected by erosion. One these areas, central Ebro valley, northeast Spain, provides case-study climate and human impact on soil A rainfall gradient exists from centre valley (300 mm, mean annual precipitation) towards Pyrenean middle mountains (>800mm). The occurrence convective storms coupled with high erodibility gives rise to very fragile agrosystems which essentially constitutes non-renewable resource. Socio-economic changes have occurred Spain over last 50 years more recent induced agrarian policy European Union led land abandonment use changes. Such produced hydrological edaphic modifications had an effect Two representative physiographic variety dry farming been selected assess erosion caused study sites located environment near Zaragoza city other temperate mountains. Soil has measured experimental plots Gerlach traps tipping buckets connected data loggers simulated area. Fallout caesium-137 also used movement. results obtained demonstrate significant differences between two environments. Cultivation main factor causing environment, where shrubs protective surface. Higher crop productivity mountain area helps protect soil. severity along problems associated farmland urgent need for appropriate conservation strategies. INTRODUCTION In some regions such as Aragon basin, become important problem affecting rainfed agriculture. extent this generated much about future agrosystems, implement measures. Socio­economic and, recently, application encouraged use. change. Aragon,