Spatial variability of soil macroporosity in irrigated area before soil preparation and after crop harvest using conventional tillage and chiseling

Abstract

In the second semester of 1995, at the Technical Center of Irrigation of Universidade Estadual de Maringá, in Maringá, State of Paraná, Brazil, macroporosity changes between samples collected before soil preparation and after bean crop harvest in two central-pivot-system irrigated plots, one submitted to conventional tillage and the other to chisel plow, were investigated. The conventional tillage reduced the macroporosity value, but increased the soil density average value in the period studied. On the other hand, the chiseling system increased macroporosity average to 83%, which improved aeration, roots development and water infiltration conditions. The initially similar spatial structural dependence of both plots was not modified, except for the fact that chisel plowing reduced the structural nuggets; of the experimental semivariograms, whose range remained the same for both treatments.