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t
his article is the 25th of a series of articles highlighting a
specific crop species that can play an imperative role in con-
servation agriculture (CA)-based crop-pasture rotations.
Besides improving the physical, chemical, hydrological and
biological properties of the soil, such species, including annu-
al or perennial cover crops, can successfully be used as animal feed.
Livestock production systems are in many ways dependent on the
utilisation of forage species, in this case as an annual cover crop,
and can therefore become an integral component of CA-based crop-
pasture rotations. It is imperative to identify a plant species fulfill-
ing the requirements of a dual purpose crop, i.e. for livestock fodder
and/or soil restoration.
This article focuses on an annual summer grass cover crop with the
potential to be used to improve soil conditions and to provide high
quality fodder for ruminants and horses.
Eragrostis teff,
teff
or
tef
Teff originates in Ethiopia and is an annual scantly tufted grass that
can grow to 1 m tall. Teff is a very leafy plant and has a high yield of
grain when in seed. This is a C4 plant and uses light efficiently in low
moisture conditions.
It is also a shallow-rooted grass and has the ability to establish
quickly in many different soil types. There are many different types
of teff with three main types of seed colour. The white teff is slow
maturing, grows in cooler conditions and is superior for grain pro-
duction. Red and brown teff are faster maturing grasses and are
superior for fodder. Because of its good nutritional qualities, teff is
most commonly produced as a hay crop in South Africa.
Agro-ecological distribution
Teff requires an average rainfall of as low as 350 mm per annum, and
the grain teff can grow with rainfall as high as 2 500 mm per annum.
This species resists moderate droughts, hot weather, poor soil and
low fertility.
Most cultivars require at least three good rain showers during
the early growth and a total of 200 mm to 300 mm of water. Most
teff in South Africa is grown in areas that receive between 400 mm
to 900 mm rainfall. White teff has the ability to tolerate some frost;
however it will not survive prolonged periods of extremely cold
temperatures. On the other hand teff can also tolerate high tempera-
tures of 35°C and higher.
With regards to soil types, teff is adapted to a variety of soil types
and can be grown on sand to turf soils. It should be noted that even
though teff grows on clayey soils, such as black turf soil, it does not
tolerate waterlogged conditions. It is therefore essential that the
soils in higher rainfall areas should be well-drained for optimal teff
production. From a soil chemical perspective, soils with a pH lower
than 5 will not significantly affect the growth of teff, thus making
this species acid soil tolerant.
Management and utilisation
Since teff is a crop mainly grown for hay production, it is extremely
important to ensure a firm, fine seedbed for the very small seeds
sown. Consequently a level and uniform seedbed is required
which will facilitate an easier hay harvesting process. When planting
teff, it is essential to consolidate (roll) the seedbed before and after
seeding. It is also important to make sure that the soil fertility levels
are up to standard, especially the phosphorus (P) and potassium (K)
levels being at least 15 mg/kg soil and 100 mg/kg soil, respectively.
Once the teff has germinated, the pasture can be fertilised twice
during the growing season with two applications of 50 kg N/ha. If
too much nitrogen is applied, this can result in the lodging of the
species which results in difficult harvesting and significant loss of
dry matter (DM) yield.
When planning on seeding teff, it is important to take note of wheth-
er it is being planted with other perennial sub-tropical grasses, such
as
Eragrostis curvula
(weeping love grass/
oulandsgras
) – which is a
common practice, or on its own, as this determines the seeding rate.
Teff is usually planted in early summer and can then provide at
least two harvests. However, when planted mid-summer one har-
vest is usually obtained. The sowing rate for sandier soils is 7 kg/ha
to 10 kg/ha and for clayey soils 10 kg/ha to 15 kg/ha and should be
planted between mid-October and mid-January.
Teff is often used as a
‘
nurse crop
’
for many perennial pasture crops,
and is quite commonly used in a mixture with Rhodes grass and
Smuts finger grass.
WAYNE TRUTER,
University of Pretoria,
CHRIS DANNHAUSER,
Grass SA,
HENDRIK SMITH,
Grain SA and
GERRIE TRYTSMAN,
ARC-Animal Production Institute
Integrated crop and pasture-based
livestock production systems
– Part 25
AGRICULTURE
Conservat ion
Series
ON FARM LEVEL
Conservation agriculture
April 2016
42