Dense (Climo and Richardson 1984) and long (Watkin and Clements 1978) pastures at grazing offer some protection to soils from treading damage and reduce sediment loss compared with loss from a very short canopy pasture (Betteridge et al.
1998) showed sediment loss was greater from slope soils, which were more prone to treading damage as a consequence of lower plastic and liquid limits, than from adjacent soils with easier contours.
To determine the immediate effects of sheep and cattle on the soil and pasture resource of a hill land, a single severe treading was imposed by sheep and cattle on the wet soil above its plastic limit.
Within each treading subplot, five 2-m contometer transects were established down-slope, crossing banks, slopes, and tracks, to enable representative changes in microtopography during a grazing event to be accurately described.
Measurements and scores were made before and after the first treading on all 4 subtreatments and following the second cattle treading on untrodden and [C.
Surface disturbance, or the difference in height of each pin caused by a treading event, was analysed as net disturbance and absolute disturbance.
The effect of animal treading on soil roughness was described as the difference in units of standard deviation between roughness before treading and after treading.
Water-filled porosity (WFP) at the time of the first and second treading events was calculated (Linn and Doran 1984):