Mitigation of the Gradient of Chemical Properties in the Rooting Zone of Dystrophic Oxisols by Gypsum and Lime Inputs under a No-Till System

ABSTRACT Improvement of soil chemical properties in dystrophic Oxisols managed under long-term no-tillage system (NTS) with surface broadcast lime has been, frequently, restricted to a shallow topsoil layer. As a consequence, a sharply-defined chemical quality gradient is created, with deterioration from the surface towards deeper layers in Oxisols in southern Brazil. The aim of this study was to assess the temporal effects of gypsum, applied alone or in combination with lime, on Ca2+ content and Al3+ saturation in the rooting zone (RZ) (0.00-0.40 m). Four experiments were conducted from 2009 ...