Abstract

GVOZDENOVICH, Jorge Jesús; PEREZ BIDEGAIN, Mario; NOVELLI, Leonardo Esteban  and  BARBAGELATA, Pedro Anibal. ¿Puede wepp mejorar la predicción de la erosión de suelos respecto a USLE?. Cienc. suelo [online]. 2017, vol.35, n.2, pp.259-272. ISSN 1850-2067.

Soil degradation due to water erosion affects the productive potential of arable lands. This problem is magnified by undulated landscapes, intense rains, and high frequency of soybean crops in Argentinean agricultural fields. A number of models were developed to study this phenomenon, including the Universal Soil Loss Equation (USLE) and the Water Erosion Prediction Project (WEPP). Locally, USLE has been adjusted and validated, yet it is necessary to ensure models that allow us to account for sediment production and runoff with a higher level of precision. The objectives of this study were to compare measured and WEPP estimated water runoff and measured sediment yield in runoff plots with those estimated with USLE and WEPP. The study was carried out in Paraná (Argentina), in four runoff plots: bare soil, maize, soybean at 70 and 35 cm between rows. Nash-Sutcliffe index (E), R², confidence interval, and coefficient of variation were used to evaluate the models. Comparing average annual soil loss there were no statistical differences between measured and WEPP estimated values, while USLE overestimated soil loss in continuous corn and bare soil treatments. Likewise, annual sediment estimation results indicated a low efficiency of USLE model for all the treatments (E from -8.94 to 0.14), whereas WEPP showed good to very good efficiency (E from 0.17 to 0.61). Runoff water was successfully estimated using WEPP model for the four treatments evaluated (E from 0.27 to 0.44). USLE failed to predict extreme low and high soil loss values measured in continuous soybean plots. The use of the WEPP physical model allowed to better represent the reality of the water erosion susceptibility for different productive systems of Argentinean pampas region.

Keywords : Water erosion; Sediment; Runoff.

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