3.4. Rainfall simulations
With rainfall simulations using a small, mobile, jet rainfall
simulator it can be documented that the reduced infiltration
capacity leads to appreciable increased runoff rates and
increased soil erosion rates with respect to currently used
agricultural land and areas used only for pasturing (Table 5).
With an average runoff coefficient of 61.3% the plot of
crusted young fallow land is higher than that of freshly tilled
uncrusted plots of arable land by a factor of 4.6 and by a factor
of 2.2 over that of older plots of fallow land with a higher level
of vegetation cover and strong bioturbation. The absolute
maximum value of runoff coefficient for the young crusted
fallow land was extremely high at 80%. On livestock paths the
older fallow land can be seen to have values of up to 75.6%, but
most of the measurements are significantly lower. The surface
runoff started on the young crusted fallow land within the first
5 min, whereas the late start on the freshly tilled arable land
shows that during the test sealing processes took place here
creating runoff and soil detachment after 8 min at the earliest,
but sometimes even much later.
The rainfall simulation experiments raise some assumptions
for a ranking of runoff coefficients and soil detachment rates: As
far as soil detachment is concerned, the arable land had an
average of 29.6 g m−2
, ahead of the crusted young fallow land
with 23.6 g m−2 and the older fallow land with 16.1 g m−2
,