Resumen

TAVARES FILHO, João; FELTRAN, Clarissa Tieme Matsuda; OLIVEIRA, José Francirlei de  y  ALMEIDA, Edinei de. Modelling of soil penetration resistance for an oxisol under no-tillage. Rev. Bras. Ciênc. Solo [online]. 2012, vol.36, n.1, pp. 89-95. ISSN 0100-0683.  http://dx.doi.org/10.1590/S0100-06832012000100010.

Soil penetration resistance is an important property that affects root growth and elongation and water movement in the soil. Since no-till systems tend to increase organic matter in the soil, the purpose of this study was to evaluate the efficiency with which soil penetration resistance is estimated using a proposed model based on moisture content, density and organic matter content in an Oxisol containing 665, 221 and 114 g kg^-1 of clay, silt and sand respectively under annual no-till cropping, located in Londrina, Paraná State, Brazil. Penetration resistance was evaluated at random locations continually from May 2008 to February 2011, using an impact penetrometer to obtain a total of 960 replications. For the measurements, soil was sampled at depths of 0 to 20 cm to determine gravimetric moisture (G), bulk density (D) and organic matter content (M). The penetration resistance curve (PR) was adjusted using two non-linear models (PR = a D^b G^c and PR' = a D^b G^c M^d), where a, b, c and d are coefficients of the adjusted model. It was found that the model that included M was the most efficient for estimating PR, explaining 91 % of PR variability, compared to 82 % of the other model.

Palabras llave : no-till; compaction; physical properties; organic matter.