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 so 剕