FOCUS
Natural resources andenergy
Special
current expansion of erosion with appropriate soil conservation
measures or structures, expansion of conservation agriculture (CA)
under cultivated areas and protecting the natural vegetation from
overgrazing through rotational grazingmanagement systems.
Inaddition to site-specific rehabilitationof existingerosion features,
the identification and mapping of currently vegetated or erosion-
free areas (that are susceptible to erosion) can be achieved. It is
especially important to identify areas that are intrinsically sus-
ceptible to erosion before being extrinsically triggered or accele-
rated by land use and human-induced reduction of the vegetation
cover. Appropriate strategies then need to be designed for
susceptible areas inorder toprotect the current vegetation cover.
Excessively high soil erosion rates normally occur under aggressive
tillage-based cultivation practices, especially on erodible soils
during peak events (heavy thunderstorms) and on steeper, longer
slopes. The potential of CA to protect and improve soil resources
and improveproductionhasbeenwell documented. Under CA, crop
residuesare retainedon thesoil surface toprotect it from theerosive
impact of raindrops andwind.
The use of cover crops can further increase the crop canopy
and ground cover on the soil, while the presence of permanent
and strong living root systems in the soil, greatly enhances the
resistance of the soil against erosion. Ultimately, the increased
organic matter levels in the soil due to quality application of CA,
Tsitsavalleymerge.
Figure 1: Distributionof gully erosion inSouthAfrica.
Soil erosion inSouthAfrica
– its natureanddistribution
November 2014
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