Many extensive livestock farmers use scientific management principles to conserve and improve their farms and manage drought. This is according to Dr Mias van der Westhuizen, a professional scientist in range and forage science at the Free State Department of Agriculture and Rural Development, and Prof Hennie Snyman of the Department of Animal, Wildlife and Pasture Science at the University of the Free State.
They have demonstrated that it is possible to boost a farm’s grazing capacity by up to 25%, even in regions with rainfall of not much more than 500mm/ year. Such grazing systems are based on synchronising herd management with the normal fluctuations in veld quality and production so that the animals – usually adapted cattle, sheep or goat breeds – can produce and reproduce optimally.
This can be achieved in a system in which a herd is moved through six camps with an occupation time of one to three months each, depending on camp size, time of the year and the reproductive phase of the females. The grazing periods are also alternated so that a camp is never grazed more than once during the same season during a three-year period.
The camps are grazed short, enabling a relatively long rest to maximise vigour and quality. Each camp is rested every three years for at least a full growing season, starting in July and ending in May the following year.
Effective grazing
Effective grazing management limits the negative effect of drought on veld. Long-term trials from 1986 to 1994 in the Molopo thornveld/shrubveld, during which the 1989/1990 season was very dry, showed that the basal cover of plants in ungrazed plots tended to recover completely the following season while grazed plots did not. Bare patches were also more common in the grazed areas.
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After a drought, a farmer should seek to restore plant cover, nurturing seed production of palatable plants and establishing seedlings.
After-drought veld management tips
- Try to keep livestock off the veld for at least three weeks after good rain to promote faster regrowth;
- Keep all animals that have been fed in smaller camps for another three weeks. Alternatively, sacrifice one camp by grazing it for three weeks, then give it a full season’s rest at a later stage. Preferably, it should be one of the least drought-sensitive camps on the farm;
- Stocking rates should always be according to veld condition and potential to prevent overgrazing. When it gets dry, keep the stocking rate 70% lower than the farm’s normal grazing capacity until the veld has recovered. If follow-up rain is insufficient, reduce the stock further.
- Camps that have deteriorated badly should receive special attention. Graze them in winter only and give them long rests;
- The soil in camps with large bare patches can be mechanically scarified to limit runoff and improve water retention.
- Seed, preferably from the area, can be sown in at the same time and the patches can be covered with branches or hay to help seedlings establish;
- Retain spare veld for next spring and summer to bridge the next drought;
Evaluate grazing regularly, and not only during drought, to spot any significant changes before it is too late.
Email Dr Mias van der Westhuizen at [email protected], and Prof Hennie Snyman at [email protected].