Mei 2014
52
ON FARM LEVEL
Conservationagriculture
t
his article is the third in a series of articles highlighting a
specific pasture crop species that can play an imperative role
inconservationagriculture (CA)basedcrop-pasture-rotations.
Besides improving the physical, chemical, hydrological and
biological properties of the soil, such species, including
annual or perennial cover crops, can successfully be used as animal
feed. Livestock production systems are inmanyways dependant on
the utilisation of pasture species, in this case as a pasture ley crop,
and can thereforebecomean integral component of CA-based crop-
pasture-rotations.
It is imperative however to identify a pasture species fulfilling the
requirements of a dual purpose crop, i.e. for livestock fodder and
soil restoration.
Digitaria eriantha
– Smuts finger grass
(
Smutsvingergras
)
In 1924 General Jan S. Smuts identified a group of
Digitaria
plants
on his farm Doornkloof near Pretoria and brought this under the
attention of Miss S.M. Stent, a taxonomist in the Department of
Agriculture.
According to Smuts, this group of plants differed from other finger
grasses in the area because of its acceptability by animals. Material
collected from these plants brought upon a new species namely
Digitaria smutsii.
The grazing value of
D. smutsii
became very popular (early 1930’s)
under the influence of research done by Drs Pentz and Pole-Evans.
In 1981 the botanical name of this grass became
Digitaria eriantha
cultivar Irene, which is still available today.
Agro-ecological distribution
In theearlydays itwas commonlyplanted in thedistrictsof Pretoria,
George,Rustenburg,Kroonstad,Grahamstown,Vereeniging,Cedara
(KwaZulu-Natal), Potchefstroom, Kokstad, ErmeloandBloemfontein.
One of the reasons for its popularity is its adaptability to a variety
of climatic and soil conditions. Although it will survive rainfall
conditions of as low as 450 mm per annum, it is mainly grown in
cooler areaswith a rainfall of 550mm and higher. This grass is also
known to survive frost andwill growon almost any soil.
Management and utilisation
Because of Smuts finger’s fluffy seeds, it should be established in a
well-prepared, fineand firm seedbed. Proper rollingbeforeandafter
seeding will benefit germination and establishment. Establishment
canbedonewithpureSmuts finger grass seed, at 4kg/ha to7kg/ha,
or inmixtures. ThepopularPotch-mixturecanbeplanted indifferent
combinations:
Equal partsofSmuts fingergrass,Rhodesgrass (
Chlorisgayana
),
white buffalo grass (
Panicummaximum
) and bottlebrush grass
(
Anthephora pubescens
), in fertile soils and medium rainfall
areas.
Equal parts of Smuts finger grass, Rhodes grass, white buffalo
grass, in fertile soils andhigh rainfall areas.
EqualpartsofSmuts fingergrassandRhodesgrass, inpractically
any soil andmedium tohigh rainfall areas.
Smuts finger grass isnaturallya slowestablisher and for that reason
thecombinationwithRhodesgrass isagoodchoicebecauseRhodes
is quicker to establish. In 12 to 18 months the Smuts finger grass
will increase and the compositionwill have become equal andwith
time the Rhodes might disappear completely to leave a pure stand
of Smuts finger grass.
Smuts finger grass is a grass type which can be strategically used
in the growing and dormant seasons of a fodder flow programme.
The inherent palatability, regardless of being fertilised or not, is
ideally used as a greenpasture in the summer growing seasons and
undoubtedly as a foggage (
staande hooi
) in winter. It can also be
used as a hay crop and for seedproduction.
Smuts finger grass is often used as a foggage in the autumn and
earlywintermonths; especiallywhen the veld is shortly grazed and
themaize residues arenot availableyet. Other than just usingSmuts
finger grass to relieve thepressureon theveld, theproductionof the
grasscanbemanipulated through the fertilisation, dependingon the
expecteddrymatter requirement during specific times of the year.
WAYNE TRUTER,
University of Pretoria,
CHRISDANNHAUSER,
Grass SA,
HENDRIKSMITH,
Grain SA and
GERRIE TRYTSMAN,
ARC-Animal Production Institute
Integrated cropandpasture-based
livestockproduction systems
–Part 3
AGRICULTURE
Conservat ion
Series
