Methods for Removing Excess Herbage

In the sourveld regions, proper farm management will involve the removal of excess herbage from the veld. This is done to remove the unpalatable vegetation which is left over after the grazing cycle. During the winter periods, the sourveld vegetation becomes highly unpalatable to livestock and they will rarely be able to consume the dry mature vegetation. Therefore, removing it allows for better utilisation and regrowth during the springtime as all the moribund material gets removed. Different strategies can be implemented based on location, available implements and/or resources as well as the management objectives of the farmer.

 

Mowing of Veld

Large tractor mowing the veld to remove excess herbage.
(Source: Falcon Equipment)

This section will summarise briefly the effect of mowing on the veld and will consider some of the principles to be applied.

The veld which has been mown and the mown herbage removed from it does not need to be burned to remove surplus unused material. Mowing of the veld in summer for hay (quality fodder) will prevent the accumulation of unpalatable material which may require burning during winter. Similarly, old material left over from summer grazing, if mown for bedding (low quality) during winter, also eliminated the need for burning.

The effect of this mowing on the veld is in some instances rather different from burning. It will generally result in a denser, more diverse and more advanced (successionally) cover than does burning. Burning suppresses the yield of grassveld by some 30% – 50% during the year of burning relative to mowing but produces more palatable and nutritious spring growth. The mown herbage has considerable value as either hay, bedding or packing material.

Thus there are definite advantages in mowing veld to remove surplus herbage. However, there are only limited areas of veld which can be mown due to slope and surface conditions, and the process of harvesting for a yield of less than one ton of herbage per ha is barely economical in terms of direct returns. The indirect advantages of mowing veld in terms of improved plant cover, vigour and composition are difficult to assess in terms of Rands, but are nevertheless considerable.

 Making hay silage from excess herbage on the veld.
(Source: S&H Farm Supply)

Making hay from veld is a reasonably low-risk process because of the low moisture content of veld which allows rapid handling and the making of bedding is not influenced significantly by climate. Quality hay comes from young grass. Mowing and grazing when combined on the same camp during the same year can lead to over-utilisation of and damage to the veld.

 

OR

When artificial methods are utilised to remove excess herbage the costs can quickly escalate. Machinery such as tractors can mow and bale the grass for use as bedding. However, the expenses normally exceed the possible profit from selling it. However, under optimal circumstances where the terrain is favourable and enough excess herbage is present it can be done.

 

Burning

Controlled burning of the veld to remove excess herbage can be very beneficial for the environment

Fire is a valuable tool in the management of natural vegetation. It is a resource modifier and can be used to change the composition of the vegetation and its cover or to maintain the plant communities in a certain stage of succession. Fire has, for many hundreds of years, played a role in determining the nature of the vegetation in South Africa and therefore its management has become particularly important. The use of fire in management must be considered in the initial stages of planning. Its manipulation must be dictated by the objectives it is hoped to achieve:

• by burning,
• by the reaction of the plant communities to burning,
• by the management systems into which it is to be incorporated and
• by the local legislation about the use of fire.

This chapter will deal with the other three aspects including the objects of burning, the incorporation of fire into some management systems, and fire legislation.

Take a look at the following video, it gives a few great examples of how to effectively remove excess herbage through the use of a controlled fire.

Different types of burns. a) Head fire; b) Backhand fire; c) Stripheading fire; d) Flanking fire.

 

A. A Few Key Pointers

• ALWAYS start the fire on the downwind side next to a firebreak to prevent the fire from running into the rest of the farm.
• Make use of a backhand fire where you burn against the wind.
• Once a proper safe zone is established a head fire could be used to speed up the process and run into the backhand fire to control it. However, this type of fire is not as effective in removing all the material.
• A flanking fire or strip heading fire can be used to speed up the process yet still remove sufficient fuel.

B. Why Burn the Veld?

The use of fire especially in the grassland regions can be beneficial. All the old moribund material left over from the previous season can be removed with fire. This is essential in allowing light to pass through which is necessary for the survival of certain grass species. A more even utilisation can also be expected during the growing season. The new regrowth is more nutritious after a burn than without it which could mean improved animal performance.

Grass regrowth after a recent fire

The mesic grasslands are fire-dependent and require fire to maintain their biodiversity. Fire is therefore important for the health of the grassland and withholding it could lead to a more woody and even weedy component being present in the area. Fire suppresses woody plants in the mesic grasslands.

Removing excessive herbage from certain strategic places through firebreaks will also assist in protecting the farm against runaway fires from the neighbours or roadside. This could aid in preventing massive losses through uncontrolled fires. Proper preparation and management should be in place when attempting to do firebreaks.

C. Objectives of Burning

Before proceeding to develop a plan of fire management for various systems of land use the objectives of burning natural vegetation must be established. These objectives, with some comment on the success likely to be achieved under each objective, are considered in this section. The application of the objectives in various management systems will be discussed later.

• Fire can be used to remove surplus vegetation and facilitate access by man and animals. However, care should be taken that this advantage is not gained at the expense of deterioration in plant composition, productivity and soil and water conservation.
• Controlled burning will reduce the fuel load and thus the intensity and frequency of accidental fires. It can also be applied to make firebreaks which protect vulnerable areas. Such measures, if repeated too frequently on the same site, may produce their characteristic detrimental conditions.
• Fire can be used to facilitate the introduction of exotic species into the vegetation (eg. overseeding with improved pasture species).
• Burning can improve the acceptability and nutritional value of the existing species for grazing and browsing animals. It may be applied at specific seasons for this purpose. However, burning at certain seasons of the year, particularly when followed by close cropping, can reduce the production of vegetation and increase soil loss and the runoff of water.
• It has been suggested that burning will aid in the control of livestock parasites which spend certain phases of their life cycle on the vegetation. Some parasites, such as ticks, may be burnt in fires. However, the evidence tends to suggest that many avoid the effects of fire and that less drastic measures are more effective, eg. dipping and dosing. Fire has recently been used in the Kruger National Park to control anthrax.
• Burning may be used to maintain or develop a plant cover which is most conducive to the conservation of soil or water in a particular catchment. It does affect both the canopy and basal cover of vegetation and thus the absorption and run-off of precipitation. The response of these factors to fire on a specific site should be known before burning for this purpose.

The object of applying fire and the consequences of the burn should be evaluated before including fire in a management system. It must also be remembered that the effects of fire are modified by climate, soil and in particular the utilisation of the vegetation before and after the burn. In the section, Fire Management and Relating Legislation, we will look at some of the legislative aspects regarding the use of fire and other instances where fire is encouraged from a management point of view.