VALIDACIÓN DE UN MODELO EROSIÓN-PRODUCTIVIDAD EN SUELOS DE LOS ANDES VENEZOLANOS

Resumen

Palabras claves: Productividad del suelo, erosión, modelos de simulación, Phaseolus vulgaris  L., Andes venezolanos, Mérida.

Abstract

In mountainous areas, soil erosion by water is one of the most important land degradation processes. The nature and dynamics of the erosion phenomenon have been substantially studied, but there is much to inquire about relationships between soil pro-perties, as affected by erosion, and soil productivity. With the purpose of analyzing such relationships a model (Productivity Index) was developed to try to establish soil productivity values as a function of the following edaphic variables, closely related to growth and development of crops in tropical mountainous re-gions: available water capacity, clay content, bulk density, coarse fragment content, pH, organic matter content and alu-minium saturation. One of the models most important appli-cations is its capacity to predict the erosion effect on soil pro-ductivity. By simulation of the erosion process throughout suc-cessive remotion of topsoil layers, the model generates pro-ductivity values for different remotion levels. In order to vali-date this application of the model, the results obtained by simu-lation were compared with the field productivity values corres-ponding to different artificial remotion levels of a Typic Humi-tropept topsoil in the Venezuelan Andes. The results of this research allow to conclude that the model can be used for pre-liminary evaluation of the erosion impact on these soils of mountainous regions, particularly when there is no field research information available to evaluate the soil erosion-productivity relationship.

 Key words: Soil productivity, erosion, soil properties, Pha-seolus vulgaris L., Venezuelan Andes, Mérida.