ON FARM LEVEL
Conservationagriculture
t
his article is the fourth 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 in many ways dependant on the
utilisation of pasture species, in this case as a pasture ley crop, and
can therefore become an 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.
Chlorisgayana
/Rhodesgrass (
Rhodesgras
)
According to literature, Rhodes grasswas imported to SouthAfrica
in 1895. An information document by the Food and Agriculture
Organization of theUnitedNations (FAO), published on the internet,
reads: “
Katambora Rhodes grass originating from the banks of the
Zambesi River, inZimbabwe
”.
Katambora Rhodes grass is one of the most popular cultivars of
this species and its seed was produced for many years by tobacco
farmers in Zimbabwe. At this moment, Katambora and Boma are
the only two cultivars on the South African cultivar list, although
the cultivar, Giant (originally from Tanzania), is also used in
SouthernAfrica.
As the name indicates, Giant is a tall grower and high yielding
grass, but not palatable at amaturedgrowth stage and less drought
resistant than theother cultivars.
Agro ecological distribution
One of the reasons for Rhodes grass’s popularity is its ability to
adapt to a variety of climatic and soil conditions. In general, it is
suggested that it beplanted inareaswitha rainfall of 650mm/annum
andhigher.
Although it grows well in wetter swamp areas with soils of higher
clay content, it also grows well in the dryer areas of the Limpopo
province. It is well-known for its ability to grow in soil with a high
pH and even brackish soil. It can survive low temperatures and
even frost.
Rhodes grass is known to be a weak perennial species and can be
very productive for three to four years, but since it has a high seed
production and if left to reseed itself before defoliating it, you can
extend this period slightly.
Management and utilisation
Because of itswoolly/fluffy seeds it should be established in awell-
prepared, fine and firm seedbed. Proper rolling before and after
seeding will benefit germination and establishment. Establishment
can be done with pure Rhodes grass seed, at 5 kg/ha to 8 kg/ha in
rows and 8 kg/ha to 12 kg/habroadcasted.
When using coated seed, the seeding rate should be increased by
at least 30%. This species germinates and establishes quicker than
otherstrongperennial speciesand is thereforealways recommended
tobeplanted in amixture.
The followingmixtures couldbe considered:
Rhodes and Smuts finger grass: 2 kg/ha to 4 kg/ha of each
species.
Rhodes+Smuts finger grass+Guinea grass (
witbuffelsgras
)+
Woolgrass (
borseltjiegras
) (knownas thepopularPotchmixture).
With a:
Low toaverage rainfall year, it is recommended that 1 kg/ha to
2 kg/ha is plantedof each species.
Low toaverage rainfall year, it is recommended that 1 kg/ha to
2 kg/ha is plantedof each species.
High rainfall year, it is recommended that 2 kg/ha to 3 kg/ha is
plantedof each species.
Whenbettermoisture conservation is a requirement indry seasons,
it is advisable that species are planted in rows. The rows should be
approximately 600 mm to 900 mm from each other and it should
be consolidated properly to facilitate good germination. The tractor
wheel or compression wheel planter method has proven to be a
reputablemethod toachieve thispurpose. Inareaswithhigherrainfall
broadcast seeding (more seedper hectare), it is recommendedwith
the requirement of sufficient consolidation through rolling.
WAYNE TRUTER,
University of Pretoria,
CHRISDANNHAUSER,
Grass SA,
HENDRIKSMITH,
Grain SA and
GERRIE TRYTSMAN,
ARC-Animal Production Institute
Integrated cropandpasture-based
livestockproduction systems
–Part 4
AGRICULTURE
Conservat ion
Series
Junie 2014
48
