water infiltration and water holding
capacity of the soil.
CA and the livestock factor
A conflict of interest often occurs as
developing grain farmers in general
rely on crop residues to be utilised
by livestock. Some commercial CA
practising farmers with livestock in
their farming system apply controlled grazing. Their practice is to
withdraw the livestock once there is
no evidence of maize kernels in
their dung. The minimum mulching
requirement for CA systems is a
30% cover of crop residue at planting time. Some farmers are sceptic
about the attainability of a proper
soil cover especially in dry seasons
when crop yields are low. Under
such circumstances the establishment of fodder type crops on separate fields (soils with lower potential), such as sweet sorghums or
Japanese radish should be encouraged. The high biomass of these
crops can help to supply the fodder
required. In this way farmers will be
able to keep the soil covered as
they rely less on crop residue as a
source of fodder.
Effective weed control
Effective weed control is one of the
difficulties associated with reduced
tillage systems. Experience has
shown that when developing farmers are exposed to the advantages
of chemical weed control, usually
seen as an advanced form of technology, they will start their own
experimentation on certain herbicide combinations. At this point,
farmers who plan to change to CA
should also take note that herbicides such as Glyphosate, better
known as Roundup or its many generic variants, in combination with
Roundup Ready cultivars (maize
and soybeans), is not a “quick fix”
to all weed control problems. On
the contrary, a well planned weed
control strategy for each farming
unit is of great importance. The
proper and careful use of chemical
herbicides remains to be a big challenge to the successful implementation of CA by developing farmers.
Grain legumes as rotation crops
in CA
Developing grain farmers in South
Africa acknowledge the value and
potential of grain legumes such as
soybeans and cowpeas in their
cropping systems. However, in the
case of cowpeas, for example, farmers fail to expand in growing the
crop. This is mainly due to inadequate seed supply services in rural
areas and the lack of a reliable market for the grain. The only way to
fully exploit the value of grain legumes such as cowpeas in crop rotation is to improve the seed supply
system and to create better market
opportunities for the producer.
CA equipment and the gap
A number of suppliers of mechanized agricultural equipment in
South Africa have recently started
to exploit the demand for no-till
planters. Much more should be
done to close the existing gap between developing farmers and
these agri-businesses. Obtaining a
suitable planter, supported by an
effective after sale service, is a crucial step in starting with the practice of CA.
The implementation of
CA includes much more
than no-till or “spray
a nd plant” as it is
called by some farmers
who have been very
superficially introduced
to the concept.
Preparing to make the shift
to CA
Farmers need to be convinced that
CA can be successfully implemented
under their unique production conditions. On-farm experiments provide an ideal “classroom” to expose
farmers to CA practices and to compare it with the conventional system over time. Farmers, considering
CA as an alternative production system, are encouraged to become
engaged in such activities through
their local organizational structures.
In this way many valuable lessons
can be learned and much money
can be saved.
CA is no cure for poor farming
methods and the basic principles of
good crop management should
always apply. Prior to any attempt
to change to CA, farmers should
make sure to remove all possible
conditions that will limit the production potential:
Brake any plough pan that
might exist in the soil
Rectify all problems of soil acidity the year before entering CA
Correct any soil nutrient imbalances
Get rid of high infestations of
problem weeds such as coach
grass
Stopping the degradation of our
vulnerable soils and opting for a
more sustainable grain production
system should now rank much
higher on the agenda of farmers in
the developing sector of our country. That been said, we should remember that such a significant
change in a system as in Brazil for
example, could not have happened
without the purposeful devotion
and team effort from all relevant
role players.