The Effect of Agricultural Soil Compaction on Physico-Mechanical Properties of Silt Loam Soils of Njoro, Kenya
Abstract
In order to cope with the demand for more food for the ever growing world population, it has become necessary to intensify farming.Agrivultural machines movement across the field increases soil compaction. The objective of this study was to rstablish the effects of soil compaction 0n selected soil physico-mechanical properties. Afactorial experiment in a completely randomised design was used. Tests were conducted on 18 plots to investigate the effect of five tractor wheel pass treatments (1, 2, 3, 4, 5) and a no whool treatment on bulk density, penetration resistance, soil cohesion, angle of internal friction and soil shear strength at three depths (0 -20, 20 - 30 and 30 - 40 cm) with three replications per plot. The results showed that increasing the traffic wheel passes and depth resulted in significant inccrease in bulk density (1291 to 1593 kg m-3), penetration resistance (0.64 to 1,34 kPa), soil strength (121,20 to 156.97 kPa), angle of internal friction (29 to 350) and soil cohesion (5.84 to 8.42 kPa) at the 5% level of confidence.. Soil compaction was found to be a dynamic process transmitted to the lower depths through the soil matrix.It was concluded that althhough subsequent wheel passes hve a smaller additional effect on the studied properties , it is cautioned that additional passes may lead to increased rillage requirements,
