Effect of two-axle and three-axle sugarbeet tanker harvester on selected soil-physical properties in dry and wet soil conditions
Keywords:sugarbeet tanker harvester, soil moisture conditions, bulk density, soil penetration resistance, saturated hydraulic conductivity
The effects of two-axle and three-axle sugarbeet harvester under dry (gravimetric soil water content 20%) and wet (gravimentric soil water content 30%) soil conditions on bulk density, soil penetration resistance and saturated hydraulic conductivity were determined in a long-term non-ploughed field with a silty loam soil in the Pannonian region of Austria. The tyre-inflation pressure of the sugarbeet harvester was set to 140 kPa in the front axle and 190 kPa in the middle and rear axles. The total weight of the three-axle harvester was distributed equally with about 20 Mg each axle. Two-axle harvester distributed the total weight of 49.1 Mg to the rear axle with 27.3 Mg and to the front axle with 21.8 Mg.
The differences of bulk density (10-15 cm, 25-30 cm, 50-55 cm) between treatments un-wheeled and wheeled with two-axle and three-axle sugarbeet harvesters were small. Under dry conditions, the soil penetration resistance was not affected by the sugarbeet harvester. The soil penetration resistance was higher in the top soil of the wet treatment after rolling with the two-axle sugarbeet than three-axle sugarbeet harvester whereas the subsoil (<23 cm) was not affected, likely because of decreasing water content.
The saturated hydraulic conductivity at 10-15 cm and 25-30 cm was not affected significantly by the sugarbeet harvester traffic, whereas in the soil depth 50-55 cm higher values were found. The three-axle harvester on wet soil reduced the saturated hydraulic conductivity in the top soil below the critical threshold value of 10 cm d-1.
The results clearly demonstrate that under dry soil conditions, that two-axle and three-axle sugarbeet harvester with low tire inflation pressure (140 kPa front, 190 kPa middle and rear) did not change the analysed soil properties. Also under wet conditions the effects were small – mainly because of the low tyre inflation pressure. As a result of this, we concluded that soil protecting sugar beet harvesting requires a good load carry capacity of the soil.