Using beryllium-7 to evaluate soil erosion processes in agricultural lands in semiarid regions of Central Argentina

摘要

This work presents the results of a soil erosion study using the Be-7 technique. This technique estimates the water erosion/deposition from the comparison between Be-7 soil content of a reference site and an eroded or sedimented site. The soil samples were collected from an agricultural area of the semiarid region of Argentina near San Luis City, which has a marked rainfall season. The area has been used for crop cultivation, being subjected to plowing practices. The Be-7 in the Reference Site was in the first centimeter of soil, showing the typical exponential decreasing of Be-7 soil content with depth, with the Be-7 inventories value being 340 +/- 50 Bq m(-2) for the dry season and 571 +/- 48 Bq m(-2) for the rainy season. The Be-7 technique was applied to a potential eroded site subjected to traditional tillage practices (plowing). A net soil erosion value of 13.5 t ha(-1) (1.35 kg m(-2)) was obtained. From the assumptions of the applied technique, we can draw the inference that this erosion was caused by rains produced in the month prior to the date of soil sampling.