Penetration resistance and agronomic characteristics of soybean affected by soil management and sowing speed systems

With the short period of the sowing process, we observed an increase in the seeder speed set in several soil management systems that may result in decreased soybean yield and problems with penetration resistance. We aimed to assess the penetration resistance (PR) and agronomic characteristics of soybean on soil tillage and sowing speed. The randomized block design in split plot with four replications was used. The treatments consisted of six management systems, applied to the plots: no tillage (NT), no tillage and chiseling (NTc), no tillage and cross chiseling (NTcc), conventional tillage (CT), reduced tillage (RT) and conservation tillage (CsT) and four speeds, (4.6; 5.5; 7,3 and 7.8 km h-1) applied in the subplot at the time of soybean seeding. We observed in the deep layers 0.0 – 0.10; 0.10 – 0.20 and 0.20 – 0.30 m significant effect of tillage systems on the PR of the soil. The NT system showed the highest value of PR compared to other management systems studied. In the NT should be used sowing speeds above 5.5 km h-1 to decrease the compression. Low speeds favor higher yield by improving pods per plant. Speeds in the working range (5-7 km h-1) promote higher productivity by improving the number of pods per plant, and provide better stand.