Principles of Resting Practices

Rotational resting is an important part of veld management systems

 

All veld management systems are based on the principles of rotational grazing, primarily to satisfy the growth requirements of the plants. The most important single principle is the alternative utilisation and resting of veld. The rest periods and graze periods must be given in such a way that the veld can maintain and improve itself.

 

Introduction to Veld Resting

A variety of veld types can benefit from implementing rotational resting in the veld management strategy. (Source: The Nature Conservancy)

 

Rotational resting is a suggested strategy for a variety of veld types, mostly sourveld areas but also savanna habitats, albeit it must be used in conjunction with other management strategies. A full growing season’s rest is regarded to be sufficient in sourveld environments to allow for grass vigour recovery and contribute to enhanced seed yield. It also enables preferred species to compete more successfully against less preferred species. Without adequate management, the source deteriorates as preferred species lose vitality and finally perish from their inability to endure intense grazing.

Rotational resting focuses on the needs of the plant which ultimately ensures long-term vigour and sustainability of the veld. The Recovery period or absence of animals in a camp focuses on the needs of the livestock

 

It is important to differentiate between rotational resting, which is based on the needs of plants rather than livestock, and the recovery periods that are a component of a rotational grazing system. The presence of rests in a rotational grazing system does not have the advantageous impact of rejuvenating vigour. Within a rotational grazing system, livestock is temporarily relocated from a specific area to facilitate the regrowth of grass. This is a period of recovery rather than a period of rotational rest. Certain authors employ the term “deferment” to describe the practice of intentionally withholding certain areas from livestock until a later point in the season.

Following a period of grazing, grasses utilise their root reserves to initiate regrowth. Persistent overgrazing without adequate periods of rest results in the depletion of the plant’s root reserves, potentially leading to the plant’s demise. For species that are favoured, such resting periods are even more crucial. In the absence of any grazing management interventions, the veld undergoes degradation as a result of overgrazing or selective grazing, leading to the replacement of preferred species. Rotational grazing, although not considered effective in closely controlling defoliation patterns (that is, reducing selective grazing behaviour).

Vigour refers to the grass’s capacity to generate substantial amounts of fertile seed and provide nutrients to both new and existing tillers, ensuring its survival from one season to the next. The concept of vigour, which refers to the capacity of plants to regrow after defoliation, has led to the proposal that the productivity of grass plants in the season following defoliation can serve as a measure of vigour when compared to similar plants that have not been grazed.

To achieve a healthy and strong grass sward in the spring, it is important to ensure that the grass plants have enough stored energy in their roots. This can be accomplished by implementing a rotational resting period. The timing of the rest period is crucial, even in systems that involve intense, brief grazing followed by a recovery period of 90 to 120 days. However, this rest period may not always be sufficiently long or occur at an optimal time.

Implementing rotational resting for a complete year, or at least for the duration of the growing season, guarantees that the palatable grass plants can maintain their vigour. This allows them to better endure subsequent grazing. In sourced areas, the utilisation of grass during the winter dormant period is unlikely to impact the condition of the veld. Therefore, grazing should occur from the onset of the first frost until the beginning of spring growth.

In addition to its impact on livestock production and the condition of the grassland, rotational rest also enhances vegetation cover, leading to improved water infiltration and reduced run-off, consequently mitigating erosion.

Postponing grazing until after flowering does have the limitation of leading to less appetising and lower quality grazing. The species composition of an area will dictate the degree to which this issue is problematic.

When implementing a rotational rest system that eliminates grazing for an entire year, stocking rates need to be adjusted to account for the absence of a portion (typically 25%) of the grazing area for that year. This is not the case in areas that can be grazed in the winter (such as high-altitude regions where the grass is dormant).

 

Effective Resting of Veld

Effective veld resting should result in an active and healthy grass sward. (Source: Harry Rose)

 

Resting of veld can ensure the success or failure of any veld management system. The balance of animals in and out of a camp is not necessarily a rest unless the period is so long that it serves a definite purpose.

There are different reasons why a veld can be rested, for example:

• To allow for the accumulation of reserves during autumn (grasses), which will ensure physiologically healthy plants in the next season.
• To allow plants to recover after a grazing by which the plants are given the chance to complete their physiological processes without being disturbed, to produce grazeable material and to recover their vitality.
• To overcome critical growth periods, for example during spring just when summer grasses start to grow or just after a rain at the end of a severe drought.
• To make provision for reserve veld for use in difficult periods.
• To make provision for the establishment of seedlings.
• To make provision for the seed production of desirable plants.

Just as in the case of a grazing period, the season, length and regularity of rest periods can also vary. To ensure effective resting the farmer must know how to rest his veld to achieve a certain goal. It is further important that the resting of veld must be correlated with certain physiological stages in the growth activity of plants, to be effective. In dealing with the growth cycles the so-called critical growth periods during the growth cycles were pointed out. It is logical that a critical growth period, when the plant is very sensitive to defoliation, will also be an important rest period.

 

Season of Rest

The seasons during which the veld and vegetation are rested all serve a different purpose

 

The effect of resting during the different seasons can be summarised as follows:

A. Spring and Early Summer Rest

During spring and early summer, grasses rely on their root reserves to start vegetative growth

 

This is a critical period for summer grasses which must start to grow from their reserves. In the Karoo, where the springs are often very dry, a rest just after the first spring rains is very important. A spring and early summer rest will therefore increase the production and vitality of grasses. It also increases the productivity of Karoo bushes and shrubs as well as the seed production of Karoo bushes which flower and seed in spring. Rest during this period can also promote the establishment of grass and karoo bush seedlings, especially if very good rain is received during spring. In sour grassveld, a spring rest is less important and it must not be too long because the sour grasses tend to become unpalatable within a relatively short period.

 

B. Full Summer Rest (Full growing season rest)

Summer rest results in the production of a high quantity of grass matter

 

Rest during this period usually ensures the production of a big volume of material (especially in grassveld areas) and the production of sufficient grass seed. It may however happen that the seed will not be ripe before late autumn. A full summer rest can also ensure that seedlings that have become established during spring will get enough time to grow out sufficiently. A full summer rest will also ensure vigorous plants. Shrubs will also benefit from a summer rest but Karoo bushes will benefit relatively little from a summer rest.

 

C. Late Summer and Autumn Rest

Autun rest assures sufficient accumulation of reserves

 

Perennial summer grasses benefit very much from an autumn rest because it ensures an undistributed accumulation of reserves. This ensures vigorous plants in spring, which start to grow early and helps the plants to withstand adverse conditions like cold and droughts. An autumn rest is of special importance in the Karoo because autumn is the most important growing period for Karoo bushes and also the most important growing period for the veld as a whole. Germination of seeds and the establishment of seedlings, especially Karoo bush seedlings, takes place during this period Autumn is also the most important flowering and seeding period of many Karoo bushes while the seeds of many grasses ripen during autumn, especially when the rains have come late in the season.

 

D. Winter Rest

Winter grasses can benefit from a winter rest and winter grazing can harm summer grasses

 

Summer grasses benefit little from a winter rest but they can be harmed by winter grazing. Winter grasses benefit from a winter rest. Karoo bushes and shrubs also benefit from a winter rest.

Quick summary of the aim of resting grass or karoo bushes.

Aim of rest	Grass	Karoo bushes
Accumulation of reserves and overcoming of critical growth periods	Autumn and spring	Autumn and spring
To regain vitality	Any growing period especially after a grazing
Seed production	Spring, summer and autumn	Autumn and spring
Establishment of seedlings	Autumn and spring especially after good rains	Autumn and spring
Reserve held	Summer and autumn	Autumn and winter

 

E. Length of Rest Periods

The length of a rest period mainly depends on the aim of the rest period. A rest for the seed production of grasses will necessarily be longer than the rest period for the recovery of vitality. Unfavourable climatic conditions during the rest period often mean that the rest period should be longer to have the desired effect. The lower the rainfall the longer the rest periods will be because the veld recovers more slowly. In the Karoo, a rest period should not be shorter than four months, except when growing conditions are very favourable. Rest periods can also be as long as 18 months. It is desirable that the rest periods within a system should not all be of the same length, but shorter and longer rest periods (rest periods for seed production, establishment of seedlings and recovery of vitality) should follow each other.

 

F. The Regularity (Frequency) of Rest Periods

The regularity of rest periods will depend on different factors, which are discussed below.

The condition of the veld:

The poorer the condition of the veld is, concerning the potential, the more rest the veld will need. Poor veld especially needs rests for seed production and the establishment of seedlings and it may even be necessary to establish desirable plants through seed and mechanical measures (radical veld improvement). Veld in good or excellent condition mainly needs rest periods for the recovery or maintenance of vitality.

The type of veld:

Dense sour grassveld under high rainfall conditions requires relatively less rest than sparse, sweet grassveld under low rainfall conditions. Under high rainfall conditions a rest for seed production every four years may be sufficient, but it will probably be insufficient for veld under low rainfall conditions. Depending on other factors it can be stated that the lower the rainfall, the more regularly veld must be rested.

The succession of rest periods:

If rest periods can follow a certain pattern, the success thereof can be increased. An example of this is when a rest period for seed production is followed by a rest period for the establishment of seedlings. In the same way, a rest period for seed production can be preceded by rest periods that will ensure vigorous plants. In the case of grassveld an autumn rest, followed by a full season rest, followed by a spring and early summer rest, is an example of such a succession of rest periods. In other words, care should be taken not to destroy the effect of a rest period by grazing.

To summarise, the following can be repeated. For effective rest:

• The veld must be rested during the time of the year when the purpose or aim of the rest can be achieved best;
• The veld must be rested long enough so that the purpose can be reached;
• The veld must be rested often enough to fulfil the requirements of the veld; and
• Sufficient veld should be rested at the right time to provide enough reserve grazing for drought and winter periods.

 

Effective Utilisation of Veld

The utilisation of vegetation and the effects thereof on the plant have been discussed in detail in the previous units. To combine effective utilisation with the minimum damage the following practices must be kept in mind:

• Try to keep the grazing periods as short as practically possible without cutting the rest periods so short that they serve no purpose.
• Try to separate the different vegetation types as effectively as possible, make the camps as small as possible, and try to have as many camps as possible. Through this, the aims described above will be reached more easily.
• Camps must have enough and properly spaced watering points.
• Try to combat selective grazing as far as possible.
• Try not to defoliate the palatable plants more than 60% during a single grazing period.
• Use animals of good quality which are adapted to the veld type and which are effective utilisers. The use of cattle on the grassveld will, for example, help the farmer to combat selective grazing and defoliation.
• Try not to graze the same veld in the same season (time of year) in successive years.