The Objectives of Veld Management

It is important to have specific veld management objectives

Aim of Veld Management

The aims of veld management are:

• To utilise the veld in such a way that both the veld and the livestock will benefit;
• To improve the veld and, once having achieved this, aim to maintain it in a condition which produces the maximum amount of high-quality feed per unit area.

In doing this the soil will be conserved and water will be utilised efficiently. To achieve this objective, it is necessary to control the grazing of livestock and sometimes the habits of man.

Grazers, in the main, use various methods to achieve the aims of veld management. Of these measures the following four are the most important:

• It is recognised that veld is heterogeneous and that small areas or units differ from one another concerning acceptability to livestock and herbage production. Thus, fencing should be used to delineate homogenous areas with uniform production attributes.
• As each ‘uniform’ unit is different from its neighbour it must be managed separately and according to its attributes. To do this it is necessary to evaluate its condition and estimate its current grazing capacity and its most productive seasons.
• During each year perennial grass veld develops through several physiological growth stages from emergent growth in spring, through seeding and autumn translocation to winter dormancy. Depending on the condition of a unit the resting of veld in rotation during some of these periods may promote its vigour and re-establishment.
• The duration, frequency and intensity of utilisation of grass veld have a marked influence on the production and survival of the various species. Thus, the utilisation of the veld must be adjusted to the condition of each unit.

 

Control of Problem Plants

Problem plants can be controlled with chemical or mechanical measures

 

Problematic plants do not only include different types of plants in the veld but can also include grasses which spread or encroach into areas where they do not naturally occur or which increase under certain grazing conditions but which are not desirable to have.

A. Grass as a Problem Plant

Different types of grasses react differently to grazing pressures. Grasses can be classified into different categories according to their reaction to grazing or the absence thereof. Knowing into which category the grasses fall will give a clear indication of the potential management problem in the area and why these plants are more common. As well as how the problem can be resolved.

Some grasses will decrease in a veld which is undergrazed or overgrazed. These are called decreaser species and include grasses such as Themeda triandra and Digitaria eriantha.

Increaser I species will be abundantly present in an underutilised veld and include species such as Hyperthelia dissoluta and Trachypogon spicatus.

Increaser II species are abundantly present in overgrazed veld. These include grasses such as Aristida adscensionis and Eragrostis rigidior.

Increaser III species are commonly found in overgrazed veld. Elionurus muticus and Aristida junciformis are species found in this category.

Invader species are all plants which are not indigenous to an environment. These are usually perennial invasive species or annual weeds. Some examples include Tagetes minuta, Nassella trichotoma, Arundo donax, and Lantana camara.

 

Decreaser Species	Increaser I Species
Increaser II Species	Increaser III Species

 

Invader Species

 

From top to bottom, left to right within each category. a) Themeda triandra; b) Digitaria eriantha; c) Hyperthelia dissoluta; d) Trachypogon spicatus; e) Aristida adscensionis; f) Eragrostis rigidior; g) Elionurus muticus; h) Aristida junciformis; i) Tagetes minuta; j) Nassella trichotoma; k) Arundo donax; l) Lantana camara (Sources: Andre Harmse; Ilze Joubert; David Hoare; J. Prado; Kyle Campbell; Tony Rebelo; G. Graham; Maraco La Pampa)

It is important to remember that some of these grasses are difficult to classify into only one category as the region in which they occur will affect their status. Knowing the condition of the veld as well as the grasses which are common in that area is therefore important. In one region a specific grass species may be classified as a problem plant whereas in another region it could be a beneficial grass species.

When dealing with problem grasses it is firstly important to find the root cause for the problem species and why they occur or are becoming more common. Secondly, determining the appropriate management strategy to help alleviate the problem is suggested. Applying increased grazing pressure in a concentrated area could help control certain species. However, in some cases, once a certain stage of succession in the veld has been reached it is difficult or even impossible to eliminate these species.

B. Other Problem Plants

In the sour grass veld encroaching plants fall into two categories:

• Plants which invade when under-utilised and infrequently burnt. Ex. Buddleja salviifolia and other forest margin plants.

Buddleja salviifolia invade areas which are under-utilised and infrequently burnt. (Source: Shauns)

 

• Plants which invade when over- or selectively-utilised. Ex. junciformis, Vangueria pygmaea, Senecio retrorsus as well as fynbos species like Phymatospermum acerosum and Seriphium plumosum.

a) Vangueria pygmaea; b) Senecia retrorsus; c) Phymatospermum acerosum; d) Seriphium plumosum.

 

Once established, forest margin species are difficult to remove, but they can be kept at bay with the proper application of fire and heavy grazing. The remedy for species that invade by over- or selective grazing is also quite challenging, especially with problem grass species. Maintaining a dense cover of beneficial grass species is most effective at avoiding the spread of unwanted ones.

In some cases, herbicides may be effective in controlling unwanted plants. This is however a costly and potentially time-consuming venture. Fynbos and karroid species can be controlled with fire. Other mechanical measures can also be used to remove unwanted species either by hand or with machines.

In the sourveld region, the best method to control the encroachment of undesirable plants is to have an effective grazing and resting management system together with some controlled use of fire.

 

Veld Restoration and Reclamation

Veld restoration aims to aid nature in stabilising and rebuilding deteriorated veld. It gives new hope to many land users (and animals) and is frequently the only alternative for making land more productive, even if it is not profitable in the short term. However, no veld restoration effort can succeed if the causes of deterioration are not addressed or if landowners do not fully support the project. The most typical indicators of veld degradation in southern Africa are bare patches, gully erosion, and bush encroachment. Such regions can be rehabilitated using specific measures.

A. Bare Patches

Bare patches of veld leave the soil vulnerable to erosion and removal of the topsoil

 

In dry regions, bare patches are probably the most common result of weakened veld. These bare patches are usually accompanied by a loss of the fertile topsoil and a resulting hard crust which forms on the soil surface. The primary goal of bare patch restoration is to break down the hard crust, delay precipitation runoff, improve water infiltration, and promote revegetation. There are certain practices which can be applied to restore bare patches often in combination with one another.

• Use a ripper implement to rip contour lines through the hard surface crust. Grass seeds can be sown along the contour lines.

a) Contour lines ripped to restore the veld; b) Ripping along the contour to slow rainwater runoff and increase infiltration (Source: Bush Heritage Australia)

• A basin plough works similarly to the ripper implement but in addition will create basins which can collect rainwater and facilitate plant growth. Grass seeds and kraal manure can be added to the basins.

Basins ploughed in an area where rainwater and its infiltration rate are low to create catchment areas. Grass or crops can be planted into these basins to improve production. (Source: RECA-Niger)

• Build rows of stones or plant vetiver grass (Chrysopogon zizanioides) along the contours to reduce rainwater runoff. This will prevent additional erosion and increase soil moisture content. Plants, particularly grasses, can be grown on the top surfaces of the contour lines.

a) Vetiver grass planted along ripped contour lines to decrease rainwater runoff and resulting soil erosion; b) Stone lines are packed along the contour to decrease rainwater runoff. These areas could also serve as water catchment areas which increases the growth potential for plants furthering the veld restoration process. (Sources: Vetiver Spain; Greener Land)

 

• Pack branches or grass hay over bare patches. This protects bare patches from crusting and new seedlings from early grazing and environmental conditions. Eventually, the plant material will also break down and further improve the soil status.

a) Branches are packed in eroded areas to help stabilise the area and prevent further erosion from occurring. b) severely eroded area where branches are used to form silt traps. (Source: Bush Heritage Australia)

 

• Livestock or even wildlife can be used to trample the soil and break the soil crust. Place a large number of animals in the degraded area for a short period followed by a long period of rest. In addition, the animals’ manure and urine will assist in enhancing the restoration process.

Livestock can be valuable in helping to trample and break down the soil crust and restore nutrients to the ground through urine and manure

 

B. Gullies

 

 

During gully restoration, slowing down rainwater runoff and promoting vegetation growth is done in an attempt to stabilise soil erosion. Structures can be constructed from various materials to stabilise gullies. Materials such as rocks and stones, gabions (stone baskets), geo-textiles like shade netting, old tyres, logs, concrete, vegetation and plants such as Chrysopogon zizanioides grass can all be used. The severity of the erosion, availability of materials, and finances will determine which types of materials can be used. Stabilising efforts should be done with proper design and placement to ensure effective erosion control.

C. Bush Encroachment

Large parts of the dry bushveld in southern Africa are susceptible to bush encroachment. A combination of overgrazing, lack of fire, and lack of browsers are all factors which cause bush encroachment. These conditions allow more bush saplings to survive and thereby produce a flush of seed. Sickle bush (Dichrostachys cinerea), blackthorn (Senegalia mellifera), blue thorn (Senegalia erubescens), umbrella thorn (Vachellia tortilis), and silver cluster-leaf (Terminalia sericea) are all common bush encroachment species.

Bush encroachment in the Namibian savanna is a major problem

 

In most cases, bush encroachment is usually controlled through chemical treatment or mechanical removal. In the case that optimal fire intensity and frequency can be obtained, fire can also be a valuable tool in bush encroachment management.

D. Grass and Veld Restoration

Usually, re-seeding of grasses is needed to improve restoration success. Grasses are very successful in stabilising topsoil even over a relatively short period. Native or local grasses which are adapted to the soil and climatic conditions are the preferred grass species to use. There is a higher chance of long-term success when there is a variety of grass species present. Local grass seeds can be harvested locally (for example, road reserves) by hand or machine. When extensive areas need to be re-seeded, commercial grass seed can be obtained. Seed should preferably be from species occurring within the immediate area. Ideally, the grass culm and entire inflorescence should be harvested and then packed on the bare areas. The additional plant material will help create a more favourable microclimate for the seeds to sprout in as they help provide shade, prevent the seeds from being blown away by the wind and may even decrease the evaporation rate at that specific site. All of this will increase the success rate for the seeds to establish.

Re-seeding can also be used to reintroduce palatable grasses into an area from which they have been eliminated through overgrazing. When re-seeding, it is important to not introduce invader grass species or grasses which would not naturally occur in the environment.