Influence of Limestone and Gypsum Application on Chemical Attributes of Dystrophic Yellow Latosol Soil and Corn Yield in Eastern Amazon

The objectiveof this study was to evaluate changes in the chemical attributes of the soil caused by the use of limestone associated or not to with gypsum in no-tillage system. The experiment was conducted on a dystrophic Yellow Latosol in Para state,Brazil. The experimental design was in randomized blocks in split plots with three replications. The treatments consisted of five doses of limestone (0, 1, 2, 3 and 4 t ha-1), with and without gypsum (0, 0.5 and 1 t ha-1). Soil samples were collected at depths of 0-20 and 20-40 cm. There was a significant effect on the analyzed variables at both depths. The doses of 3.64 and 2.19 t ha-1of limestone associated with 0.5 t ha-1of gypsum, were responsible for the largest increase in soil calcium content in the 0-20 and 20-40 cm layers, respectively. The highest increase in Ca + Mg content was found at 3.63 t ha-1limestone combined with 0.5 t ha-1gypsum. It was observed that 3.13 t ha-1of limestone combined with 0.5 t of gypsum increased soil CEC. The 2.89 t ha-1dose of limestone combined with 0.5 t of gypsum contributed to the increase in base saturation (V%). The use of limestone and gypsum promotes soil chemical conditions, as reflected by increased corn yield when compared with control (no treatment) plots.