| Bvumbwe catchment soil erosion study
Monitoring equipment was provided to measure sediment loss and run off
from plots with the following different land use practices:
-
improved cropping system: complete physical conservation and land use plan
set out in accordance with land husbandry recommendations;
-
traditional cropping system: intensive uncontrolled arable farming for
subsistence crops without any physical conservation works or land use plans;
-
traditional cropping system with improved physical conservation: complete
physical conservation works but without planned system of land use; and
-
forestry system: eucalyptus plantation (representing forested area).
Soil Loss (t/ha) from Bvumbwe catchment soil erosion study. Cropping systems
I to IV are explained above
|
Cropping season
|
Cropping Systems
|
| |
I
|
II
|
III
|
IV
|
| |
High input
|
Low input
|
Minimum
|
Forest cutting
|
|
1981/82
|
0.12
|
10.06
|
-
|
-
|
|
1982/83
|
0.21
|
13.70
|
2.31
|
0.09
|
|
1983/84
|
0.03
|
4.44
|
1.18
|
0.03
|
|
1984/85
|
0.13
|
14.32
|
5.11
|
0.06
|
Comparatively these results clearly illustrate the effects of the different
land use and management practices on the catchments. However, these figures
are below the estimated soil loss rates from other studies and may thus
not reflect the true magnitude of soil loss. It is important to note that
in all seasons the unmanaged catchment gave by far the highest soil loss
total, while where only physical conservation measures were employed, there
was a significant reduction in erosion rate. The well conserved and managed
catchment compared very favourably with that from the forest plantation,
illustrating the additional gains to be obtained from biological conservation
such as agroforestry technologies. (Source: Amphlett(1986)J
. |
