Alteration of soil roughness in conventional and no-tillage system according to vegetation cover density under simulated rain

• Grant number: 06/05729-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2006
• End date: November 30, 2007
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Isabella Clerici de Maria
• Grantee: Renato Lemos e Silva
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

Physical conditions of soil surface, represented for the residues cover and soil roughness produced by tillage methods, play primordial role in the reduction or rise of water and sediments losses by water erosion. The surface cover by residues reduces direct impact of rain drops in the surface, while the roughness increases water infiltration in the soil, diminishes the speed and the amount of runoff and consequently, the capacity of sediment transport. The distinct tools used in soil tillage operation create different surfaces types and roughness values, however, the extreme or the ongoing mobilization of the soil cause the reduction of this values, as well as a gradually reduction occurs because of natural arrangement and action of rainfall. Being thus, the objective of this study is to verify how the superficial roughness gotten by two types of soil tillage operation is affected by a simulated rainfall in the presence of different residue cover amount in a clay Oxissol. Treatments are moldboard plow and no-tillage, with 0, 2.5, 5.0 and 10.0 Mg ha-1 of millet on surface. Experimental will be design on random block in split plots with tree replication. Surface roughness will be determined by a laser apparatus, after the preparation of the area and after the application of a simulated rain. Also the losses of water and sediments through the plot by runoff will be evaluated.