Tillage and sowing rate in soil physical and agronomic attributes of maize crop

Resumo

Soil is an important resource to promote increased maize yield, which can occur through an efficient soil till­age system, this being directly linked to the sowing process. Thus, the objective of this study was to evaluate the influence of tillage systems in an Ultisol and sowing rate on soil physical and agronomic attributes of the maize hybrid BRS 1055. The experiment was conducted in randomized blocks in subdivided plots with four replications, with soil tillage in the plots - moldboard plow + off-set harrow of 24” (T1), off-set harrow of 22“ (T2), off-set harrow of 24” (T3) and chisel + off-set harrow of 24” (T4), and the following maize sowing rates: R1 - 5.1 km h^-1, R2 - 8.7 km h^-1 and R3 - 10.7 km h^-1. In the soil, the following variables were determined: soil density, soil porosity and soil penetration resistance (RP); and in the crop: plants per meter, plant height, first ear insertion height, viable ears, stem diameter, ear length, number of rows, number of grains per row and yield. Soil density and total porosity did not show differences between soil tillage systems. There was variation of RP in the 0.30-0.40 m layer, due to the depth and type of tillage performed for each implement. The rate variation provided changes in all agronomic attributes of the maize crop, while the soil tillage systems only affected plant height at 30 days after sowing.