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Thursday 23 May 2019
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Restoring grazing values by re-seeding grass

The grass is the feed-base of the grazing livestock in Namibia. The abundance of the most valuable grass species in many parts of the country has decreased, resulting in loss of grazing value especially in communal areas, and the carrying capacity have drastically decreased over the years.
The grasses that are now dominating are the opportunistic ones with little grazing value such as Aristida stipitata amongst others.
This has significantly compromised livestock productivity and potential income of farm lands.
The underlying reasons are the poor grazing regimes which led to overgrazing, in turn; resulting in rangeland degradation in the form of bush encroachment and soil erosion amongst others, and this is further exacerbated by the erratic rainfall activities in the country.
The grazing value of an area is determined by the grass growth/life cycle, species composition and nutritional value.
There are two types of grasses in terms of life cycles; these are annual and perennial grasses. An annual grass (e.g. Eragrostis porosa, Chloris virgata, etc.) is mainly the first grass type to emerge in abundance after the first rainfall showers, and thus, the first green food for grazing animals (e.g. cattle) after the dry season. Annual grasses have a shallow root system and few leaf materials; only need a minute amount of moisture, nutrient and sunlight.

 

These types of grass grow and produce seeds fast, but survive only during the rainy season and it dies (disappear as winter season starts). The next annual grass will only grow from the seed.
In contrast, a perennial grasses such as the common Cenchrus ciliaris (Blue buffalo grass) Schmidtia pappophoroide (Kalahari sand quick), or Anthephora pubescens (Wool grass) have a deep root system and massive leaf materials, and requires enough investment in terms of moisture, nutrients, and sunlight, thus takes longer (about 2-3 months) to grow to maturity. They are the bulk of the grazing animal’s diet throughout the year.
They shed seeds and withdraw all nutrients (from leaves and stems) back underground in their stump as food reserves for the next season’s growth. The same dormant grass stump will produce fresh/new stems and leaves, and also, the seeds will germinate into new grasses (seedlings).
These grasses shed seeds as they start to dry-up (in dry season, from May). These seeds may be found collected together in ditches on the soil. In August, the wind distribute and burry (sowing) them, and when the rainfall (watering) activities start, the germination process begins.
In an effort to restore grazing lands and produce own fodder, farmers need to re- introduce these perennial grasses by re-seeding. These grasses can be cultivated and protected like food crops in gardens or crop fields, and can also planted in grazing areas.
The seeds can be harvested from standing grass or purchased from the common agricultural inputs shops such as Agra amongst others.
It is very important that cultivated grasses are protected from disturbance (grazing), and are allowed to grow to maturity until they produce seeds and are able to regenerate themselves. Once harvested, it can be processed into hay or milled and mixed with other feedstuffs and used or stored for the period of fodder scarcity.
Issued by: Agribank




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