Agricultural Engineering and Technology Department, Jordan University of Science and Technology, P.O. Box 3030, Irbid, Jordan, 22110.
The effect of three different factors i.e. tillage treatments (no-till, chisel plowing, and disk plowing), axle load (6 and 14 tons axle−1 vehicle), and tyre inflation pressure (300 and 150 kPa) on root density and soil physical properties (bulk density, cone penetration resistance, and infiltration rate) was studied. In addition, the effect of tillage treatments on beans root density was investigated. Response to the above factors was measured up to 48 cm soil depth. Axle load and tillage treatments increased the dry bulk density and cone penetration resistance up to 24 cm soil depth, and tyre inflation pressure and axle load increased them up to 48 cm soil depth. The loaded vehicle with high tyre inflation pressure on no-till plot had the greatest effect while the unloaded vehicle with low tyre inflation pressure on chisel ploughed plots had the least effect. In general, the effects of these factors on soil penetration resistance followed the same trend but with different depth-wise magnitudes. Axle load and tyre inflation rate in the chisel-ploughed plots was higher than in no-till and disk-ploughed plots at the same axle load and tyre inflation pressure. Plants in the no-till and disk-plough treatments had a higher concentration of roots near the base of the plant compared to the plants in the chisel-ploughed treatment.
Tillage treatments, axle load, inflation pressure, soil physical properties, root density
