Soybean Yield, Soil Porosity and Soil Penetration Resistance under Mechanical Scarification in No-Tillage System

Technological development has triggered a steady increase in Brazilian agricultural production, but also brought problems due to the excessive land use. The lack of care with proper management practices has led to soil physical degradation, mainly the formation of impermeable layers, which can lead to a reverse effect, a reduction in crop yield. It can be potentiated in silage production and with the lack of cover crops. To minimize the negative impacts of soil compaction, scarification is recommended, but its effectiveness has been questioned in no-tillage system. Thus, an experimental field was implemented in Brazil in 2015-2016 season, to evaluate the mechanical scarification on soybean production in succession to silage and grain corn intercropped with Brachiaria (Urochloa ruziziensis) as well as the physical properties of the soil. The experimental layout was a complete randomized block design with four replications. The plots were composed of second crop maize (autumn) intercropped with brachiaria, in two systems- silage and dry grains. The subplots were composed of three management system- no-tillage, reduced tillage cultivation with Terrus scarifier and Fox scarifier. Corn harvesting systems as well the scarifiers use did not affect soybean production and its yield components. The use of scarifiers reduced soil coverage, plant population, and soil penetration resistance. The data suggest that there was no persistence in the benefits presented by scarification. Soybean was able to break through the compacted layers, even above the critical level, corroborating with the hypothesis that the use of scarifiers does not bring benefits in no-tillage system.