EFFECTS OF COMPACTION duE TO MAChINEry TrAFFIC ON SOIL POrE CONFIGurATION

SORACCO, CARLOS GERMAN; LOZANO, LUIS ALBERTO; VILLARREAL, RAFAEL; PALANCAR, T.C.; JORAJURÍA COLLAZO, DANIEL; SARLI, GUILLERMO OLIVERIO; FILGUEIRA, ROBERTO RAUL

REVISTA BRASILEIRA DE CIêNCIA DO SOLO

SOC BRASILEIRA DE CIENCIA DO SOLO

Año: 2015 vol. 39 p. 408 - 415

0100-0683

Soil compaction has been recognized as a severe problem in mechanized agriculture and has an inflence on many soil properties and processes. Yet, there are few studies on the long-term effects of soil compaction, and the development of soil compaction has been shown through a limited number of soil parameters. The objectives of this study were to evaluate the persistence of soil compaction effects (three traffi treatments: T0, without traffi; T3, three tractor passes; and T5, fie tractor passes) on pore system confiuration, through static and dynamic determinations; and to determine changes in soil pore orientation due to soil compaction through measurement of hydraulic conductivity of saturated soil in samples taken vertically and horizontally. Traffi led to persistent changes in all the dynamic indicators studied (saturated hydraulic conductivity, K0; effective macro- and mesoporosity, ε ma and εme), with signifiantly lower values of K0, εma, and εme in the T5 treatment. The static indicators of bulk density (BD), derived total porosity (TP), and total macroporosity (θma) did not vary signifiantly among the treatments. This means that machine traffi did not produce persistent changes on these variables after two years. However, the orientation of the soil pore system was modifid by traffi. Even in T0, there were greater changes in K0 measured in the samples taken vertically than horizontally, which was more related to the presence of vertical biopores, and to isotropy of K0 in the treatments with machine traffi. Overall, the results showed that dynamic indicators are more sensitive to the effects of compaction and that, in the future, static indicators should not be used as compaction indicators without being complemented by dynamic indicators.