Grasslands of the World.pdf - Disasters and Conflicts - UNEP

Grasslands of South Africa 105
• control the frequency at which plants are grazed by controlling the frequency
with which each camp in the system is grazed;
• control the intensity at which plants are grazed by controlling the number
of animals that graze each camp and their period of occupation; and
• reduce the extent to which veldt is selectively grazed by confining a relatively
large number of animals to a small proportion of the veldt so as to
offer them little opportunity to select.
The published results of many grazing trials (Department of Agriculture
[South Africa], 1951) suggest that while animal performance in continuous
grazing systems was superior to that of various rotational grazing ones,
continuous grazing was condemned. After the contribution of Booysen (1969),
who maintained that retaining sufficient active green biomass was essential to
optimize regrowth, further research continued into the advantages of variations
in rotational grazing. The concepts of Booysen (1969) are encompassed in the
term High Performance Grazing (HPG), with the alternative, intensive-use,
approach being High Utilization Grazing (HUG) (Tainton, Aucamp and
Danckwerts, 1999). The HPG approach is thought to perform better in the
semi -arid grasslands and savannahs, whereas HUG is more appropriate in the
fire -induced grasslands of the humid regions. The inappropriate application
of HUG, encompassed by the protagonists of Holistic Resource Management
(Savory, 1988), to the more fragile, semi-arid systems, has been controversial
and is discouraged.
The third area receiving research attention funded by the Department of
Agriculture was veldt condition assessment. In this work, floristic composition
was regarded as an indicator of the impact of management and stocking rates .
Gradient studies, which explored changes in species composition along grazing
gradients, were popular. Within this research area, it was difficult to attribute
the floristic variation along gradients directly to herbivory. Differences in
species composition were often a consequence of enrichment, trampling and
associated changes in soil structure and chemistry.
LEGUME AND FODDER INTRODUCTION
A number of subtropical pasture legumes and fodders have been screened
at sites with from 100–700 mm annual rainfall . Range reinforcement is
done on a large scale in commercial dairy regions. Favoured grasses include
Pennisetum clandestinum (Kikuyu grass ), Panicum maximum and Digitaria
eriantha , while legumes such as silver leaf Desmodium are over-sown into
natural vegetation .
Foggage (Plate 3.5) is important in commercial beef and dairy production
systems in South Africa . Graziers use a wide range of commercially available
grasses and legumes. The performance of growing beef steers grazing
foggaged dryland Kikuyu grass pastures and given limited access (3 hours
daily) to leucaena (Leucaena leucocephala cv. Cunningham) was better than