Nutrient losses due to water erosion using simulated rainfall in southern Brazil

Abstract

Erosion is the main form of degradation in the world, consequently of loss of soil, water and nutrients, provoking direct and indirect damages. The objective of this work is to quantify N, P and K losses by water erosion under simulated rainfall conditions by the application of six erosion tests in continuous cultivation of seasonal cycle species, including isolated and intercropped crops. The study was carried out in the field at the Experimental Station of Agronomy in Eldorado do Sul (RS), Brazil, in a typical Dystrophic Red Argisol. For the analysis of nutrient loss, six erosion tests with simulated rainfall were applied to the treatments between the end of October and mid-December, using the rain simulator with swivel arms of Swanson. The losses ofNand P were influenced by surface conditions,with the partial removal of crop residues and the non-mobilization of the soil. The exception was K, due to its high solubility in the soilwith a lowcolloidal activity, which was easily lost in the soilwater surface runoff, regardless of total soil surface coverage by crop residues.

Keywords

• erosive process
• runoff
• cultural sequences
• ground cover