Propriedades físicas do solo e produtividade de soja em sucessão a plantas de cobertura de inverno

Abstract

Changes in physical properties of agricultural soils affect crop productivity. This study aimed to compare results obtained winter cover plants, in its first crop cycle, in soil physical properties, in soybean productivity (Glycine max L.) in succession and biomass plant. Four species of soil cover plants were used: vetch (Vicia sativa L.), radish (Raphanus sativus L.), ryegrass (Lolium multiflorum Lam) and black oat (Avena strigosa Schreb). It was developed in Guarapuava, PR, in CEDETEG Campus of Universidade Estadual do Centro-Oeste (UNICENTRO). It was carried out the monitoring of a cycle of these crops in the fall/winter of 2010. The soil strength data were obtained with the impact penetrometer, and the soil density, microporosity, macroporosity and soil total porosity were determined from undeformed soil samples in volumetric rings withdrawn at 0,00 - 0.10 and 0,10 - 0.20m depth, after installation of the experiment and its period of greatest development (flowering). It was observed that the use of cover plants in its first crop cycle do not promote changes in soil density, microporosity, total porosity and soil penetration resistance. Meanwhile in the deep of 0,10 and 0,20m it has been seen higher numbers of macroporosity in oats and ryegrass handlings. The crops of radish presented the best production of vegetal biomass, and soybean productivity was similar after the cycle of all the cover plants.