Atributos fisicos do solos e produção de aveia branca em plantio direto sob tráfego de trator

Abstract

The traffic of machines in no-tillage areas has caused problems, as soil compaction. In this sense, the use of cover crops may benefit subsequent crops. The objective was to evaluate the influence of induced compaction by tractor traffic in no tillage under white oat crops' production components and soil physical attributes. The study was performed on the Experimental Farm of the Federal University of Grande Dourados, on an Oxisol, using a randomized block design with five replications. The treatments were composed of no-tillage for ten consecutive years and induced additional compaction states by 2, 4, 6, and 8 passes of tractor wheel from the plot's entire area. The soil bulk density, total porosity, macroporosity, microporosity, and soil resistance to penetration were evaluated in two soil layers, and the plant height, stem diameter, dry mass of plant, thousand-grain mass, and grains yield were determined. The obtained data were analyzed using variance analysis and linear regression. The effect of intensity of tractor traffic changes the physical quality of the soil and can reduce up to 32.5% of crop yield or improve its attributes, increasing up to 29.4% for the efficient production of white oat cultivated under no-tillage. In a clay soil submitted to 10 years of no-tillage of soybean and corn, and with up to eight passes of tractor wheels, the microporosity and total porosity are equal in the surface and subsurface layers, and the soil bulk density is higher, and the macroporosity and the soil resistance to penetration are lower in the 0-0.10 m layer of a soil cultivated with white oats. In the 0-0.10 m layer, the soil bulk density of 1.44 Mg m-3 causes a restriction to crop growth and white oat yield cultivated under no tillage. In the 0.10-0.20 m layer, the white oat yield is limited when the soil bulk density exceeds 1.35 Mg m-3.