agricultural production guidelines
m
Veld in KwaZulu-Natal
Co-ordinated Extension KwaZulu-Natal Veld 3.8 1999
VELD MANAGEMENT FOR THE SMALL SCALE FARMER
J M B Smith
KwaZulu-Natal Department of Agriculture
Importance
of Veld Condition
How to Improve
Veld Production in Communal Areas
INTRODUCTION
Approximately 5 059 700 ha of veld is used for extensive grazing in KwaZulu-Natal. Of this area about 2 287 500 ha is occupied by small scale farmers and is utilized mainly on a communal basis.
Much of the Province’s grazing land is in poor to moderate condition, particularly in the communal areas where it is difficult to implement a veld management system. This situation leads to unsatisfactory veld production and accelerated loss of water and soil (see Production Guideline 7.1 for more detail on soil erosion in veld). For example in the Tugela River catchment which consists mainly of veld, the sediment lost is equivalent to 5.2 tons per ha per annum. A part of this loss could be attributed to veld in poor condition as a result of over-grazing. The rate of soil formation however is less than 1 ton per ha per annum resulting in a nett loss of soil.
Stocking rate has the greatest impact on veld condition and animal performance. On farms where commercial livestock production systems are followed the average stocking rate on veld is 3.5 ha per AU which is well within the recommended norms. In the communal grazing areas there are 1 272 700 AU on 2 287 500 ha of land which translates to a very heavy stocking rate of 1.8 ha/AU. Studies have shown that such stocking rates would inevitably lead to a deterioration in veld condition, particularly in areas which receive low and erratic rainfall.
Veld condition reflects the vigour and productivity of veld, relationships which have been well illustrated in studies at the Free State University where veld was monitored over 15 years to measure differences among sites with different veld conditions. The average rainfall over the period was 520 mm. The results of the study are given in Table 1.
It is obvious that the production from the poor veld is not only 3.5 times less than veld in good condition, but the erosion is 6.5 times more and the runoff twice as much. With steeper slopes and higher rainfall the results could be more significant.
Table 1. The effect of veld condition on runoff, soil loss, water use efficiency (WUE) and dry matter production off veld in a 500 to 550 mm per annum rainfall area.
Veld condition
Good
Moderate
Poor
Veld condition score %
96.7
69.0
31.3
Basal cover %
9.0
6.0
3.0
Runoff on a 4% slope
4.8%
6.8%
10.2%
Soil loss per ha (tons)
0.6
1.4
3.9
WUE (kg DM per mm rain / ha)
2.1
1.2
0.6
Grass production (kg DM / ha)
1 022
598
281
HOW TO IMPROVE VELD PRODUCTION IN COMMUNAL AREAS
An understanding of veld management principles is required to ensure acceptable livestock production whilst maintaining the productivity of veld (see Production Guidelines 1.1, 2.1, 2.2 and 2.3 of this series for more detail on veld management principles). It must be stressed that there are no fixed recipes. Specific areas of a grazing system must be treated as separate entities each with their own potential for animal production. However, in the communal areas it is often not practical or possible to implement a veld management system which applies all of the principles. Thus the veld management principles need to be discussed in the communal area context.
Areas with different palatability and grazing potential should be demarcated. This will depend on aspect, slope, soil type and rainfall. The most effective means of separating veld types is fencing. However, in the communal areas, features such as streams, ridges, mountains and realigned roads could be used. The area boundaries could also be marked, for example, with white stones. Where fences do not exist herders should be employed to implement an appropriate grazing and resting system.Separate veld types
Grazing capacity
Stocking within the grazing capacity of the veld is an important grazing principle because this directly dictates the calving or lambing percentage, weaning mass and percentage off-take of animal products. An ‘economic’ stocking rate would optimise production but in the communal areas an ‘ecological’ stocking rate occurs because numbers of animals are more important than production for direct financial gain. It is therefore up to the community to decide whether they wish to implement an ‘economic’ or an ‘ecological’ stocking rate. However, the inevitable consequence of implementing an ‘ecological’ stocking rate is a decline in veld condition and, ultimately, a reduction in the potential of the veld for livestock production.Resting of veld
Frequent intensive grazing reduces grass vigour and yield. In order to maintain the vigour of the veld, it is essential to rest the vegetation for the entire growing season at least once in 4 years.In the communal areas the implementation of this principle could have a marked beneficial effect on veld production. This would mean that at least one quarter of the veld should be rested every year. In uniform veld all that would be required is to divide the area into four equal areas. Where a number of veld type units (VTU’s - see Production Guideline 2.2 of this series for the detail of VTU’s) are involved, each demarcated area should, as far as possible, have the same grazing capacity and VTU’s represented. The rested veld would be an invaluable source of fodder during the winter.
Prevent top layer accumulation
Due to selective grazing, unpalatable residual herbage accumulates and becomes moribund. This applies particularly to sourveld after a period of rest where the veld should be burnt. However, in the communal areas this should only constitute a problem where an ‘economic’ stocking rate is implemented.Bush encroachment
In the savanna areas, where bush is either encroaching or thickening up grass production is detrimentally affected due to competition from the trees. Preventive measures such as providing a hot burn or chemical control are seldom necessary in the communal areas as chopping trees for firewood and the browsing of goats are excellent control measures.Livestock ratios
Veld grazed by sheep alone will invariably deteriorate unless it is frequently rested. This is due to the selective grazing habit of sheep. Veld will however be better utilised where cattle and sheep are run together on the same area in a ratio of at least 1 AU of cattle to 1 AU of sheep (6 sheep).In the communal areas the grazing of cattle and sheep together could be achieved. Also, because the number of cattle (on an AU basis) carried on communal grazing lands exceeds that of sheep, the livestock ratio would be in favour of cattle.
Stocking intensity
In situations where it is possible to operate a multicamp system and, in particular, where it is difficult to demarcate areas with the same size or grazing capacity, it is necessary to ensure that the stocking intensity for all camps/grazing areas is similar. The stocking intensity is expressed in grazing days per ha (GDH).To achieve this the period of stay for each grazing area must be established. The grazing period or period of stay is obtained by multiplying the carrying capacity of the grazing area by the grazing cycle and dividing this by the carrying capacity of the total area allocated for grazing (excluding the rested area). An example, based on a four-camp/grazing area system, is given in Table 2.
Table 2. The effect of varying camp (or grazing area) size and carrying capacity on the period of stay to maintain similar stocking intensity among camps.
|
Camp number |
Area of |
Carrying |
Grazing |
Period |
Stocking intensity |
|
1 2 3 4 |
40 30 50 20 |
20 15 25 10 |
42 42 42 Rest |
14 11 18 - |
25 25 25 - |
|
Total |
140 |
70 |
Camp 1 period of stay 14 days [20 AU x 42 days ÷ (70 - 10
AU)].
Camp 3 stocking intensity 25 GDH (70 AU x 18 days ÷ 50 ha).
From the above illustration it is obvious that if all camps or areas have a similar grazing capacity the period of stay would also be the same which would ease management considerably.
CONCLUSION
The most important principle to be implemented in a communal area to improve veld production is the resting of the veld in rotation for the entire growing season. This rested veld could act as a fodder reserve during the winter period.
To be able to rest the veld it will be necessary to demarcate areas where there are different veld type units. These veld type units should then be divided into four subdivisions of equal carrying capacity with each veld type unit being represented in each subdivision. Each subdivision would receive a full growing season’s rest (at least once every fourth year). As the veld improves there must not be a concomitant increase in the stocking rate because any veld improvement will be nullified.
It is also important that all role players in the community agree on a veld management strategy and control of the veld management system in order for it to be successful.