Practices that minimize herbicide applications have been in order to avoid the risk of residual effects on the soil. Cover crops are being used to suppress and decrease the weed community's seed bank in the soil. This study aimed to evaluate the phytosociology and foliar contents of weeds and cover species and corn crop yield in an area with five primary soil tillage systems in the plot: P1 – harrow; P2 – disc plow; P3 – rotary hoe; P4 – no-tillage; P4 – scarifier and four cover crops in the subplot: T1 – brachiaria (Urochloa ruziziensis); T2 – fodder radish (Raphanus sativus), T3 – sunn hemp (Crotalaria juncea), T4 – millet (Pennisetum glaucum) and treatment with T5 – mechanical scarification without soil cover. The species of cover crops forage radish, millet, brachiaria and crotalaria provided suppression of the weed community, when compared to the subplot in which the scarifier was used without soil cover. Weed frequency, density and abundance were lower after forage radish cultivation. In scarified area without cover plants there was greater density and abundance of weeds. Forage radish and sunn hemp had higher foliar contents of macronutrients. The corn crop showed no difference in the sowing coefficient of variation and in its productivity.

Keywords: phytosociological analysis, suppression, weed control, soil cover.