Tillage systems impact on soil physical attributes, sugarcane yield and root system propagated by pre-sprouted seedlings

Soil compaction caused by intense machine traffic is a challenge in the sugarcane production system, but its implications can be mitigated by the higher content of soil organic matter and plant root growth provided by conservation management practices (i.e., no-tillage). Thus, we aim to study the impacts of tillage systems on the soil physical attributes, root system and yield of sugarcane propagated by pre-sprouted seedlings. Sugarcane was cultivated under four tillage systems: conventional tillage with harrow (CT); conventional tillage with harrow and subsoiling (CTS), minimum tillage with Rip Strip® equipment (MT) and no-tillage on soybean residue (NT). Soil parameters (soil bulk density, porosity and organic carbon contents) in the 0–60 cm layer, root system (root area and root dry biomass) in the 0–100 cm layer and sugarcane yield were evaluated from 2017 to 2019 during the cane-plant and first-ratoon cane cycles. The no-tillage system showed the highest yields of stalks, biomass and root area of sugarcane even with the highest values of soil penetration resistance and soil bulk density between the rows. The system with Rip Strip® presented the lowest yields of sugarcane stalks. No-tillage had the highest organic carbon content in the topsoil compared to the other tillage systems. The sugarcane yield showed a positive linear relationship with root biomass accumulated in 0–100 cm soil layer. Sugarcane cultivation under no-tillage system provided gains of 15 Mg ha⁻¹ in productivity and higher root dry biomass of the cane-plant cycle in the 0–20 cm soil layer. It also preserves the physical attributes of the soil, increases the soil organic carbon content and favours the increase in the yield and root biomass of sugarcane in both cane-plant and first ratoon cane.