Soil compaction and root distribution for okra as affected by tillage and vehicle parameters

Many soil physical properties and crop yield are affected by compaction and tillage systems. The effect of three different factors, i.e. tillage treatments (no-tillage, chisel plowing, and moldboard plowing), axle load (6 and 16 t/axle vehicle), and tire inflation pressure (120 and 350 kPa inflation pressures) on okra (Abelmoschus esculentus) root density and soil physical properties (bulk density and cone penetration resistance) was studied. This study was initiated in April 2000 on a loam soil (42% sand, 36% silt, 22% clay) at an experimental farm in Irbid, a district in the northern part of Jordan. Response to the above factors was measured down to 48 cm. Axle load and tire inflation pressure caused an increase in bulk density (BD) and cone penetration (CI) resistance from the soil surface down to 48 cm. The loaded vehicle with 350 kPa tire inflation pressure on no-tillage plots had the greatest effect soil physical properties measured while the unloaded vehicle with 120 kPa tire inflation pressure on chisel-plowed plots had the least effect. Plants in the no-tillage and moldboard-plowed treatments had a higher concentration of roots near the base of the plant compared to the plants in the chisel-plowed treatment.