SUSCEPTIBILITY OF SOIL TO WIND EROSION IN LA PAMPA PROVINCE, ARGENTINA

Wind erosion is the principal cause of soil degradation in the east La Pampa province, Argentina, a semiarid region with frequent and intensive winds and sandy soils with little organic matter and weak structure. Erosion is particularly critical in soils with a high content of small aggregates easily transportable by the wind. The aim of the present work was to ascertain current rates of wind erosion in the area and assess wind erosion risk using a parametric index based on the wind erosion equation, which yields values for actual (E) and potential (E(p)) erosion. Data were collected for each cartographic unit of the soil map of La Pampa province. Samples were taken of soils in representative cultivated and grazed areas within each unit. The actual rate is low to moderate in the easern part (9.4 to 27.1 Mg ha(-1) yr(-1)) and high in the southeastern part (51.0 and 53.6 Mg ha(-1) yr(-1)) of the province. The potential rare is low in the extreme northeast (23.6 Mg ha(-1) yr(-1)) and high in the southwest (178.6 Mg ha(-1) yr(-1)). Land use influences the extent of soil loss, affecting vegetative cover and the size of soil aggregates. Most soils in the study area were moderately to highly susceptible to wind erosion.