of the world’s greenhouse gas
(GHG) emissions. Moreover, each
ton of carbon lost from soil adds
approximately 3.7 tons of CO2 to
the atmosphere. Conversely, every
ton increase in soil organic carbon
represents 3.7 tons of CO2 sequestered from the atmosphere. Therefore, crop residue management
promotes carbon sequestration and
has a huge potential to reverse the
net carbon flows from the atmosphere to the biosphere.
In conclusion, there is a dire need
to develop best management practices and nutrient decision support
systems aimed at achieving higher
productivity with limited resources,
through the utilization of novel
agroecosystem approaches. CA has
the potential to greatly improve the
sustainability of crop production,
even in South African when gauged
from its widespread adoption by
farmers, especially in the southwestern region of the country
where crop yields may be affected
by intermittent drought spells. Although there are reservations about
the impact of CA, with respect to
both its effects on crop yields and
its applicability in different farming
contexts, it nevertheless stands to
reason that it will remain a key
strategy for the majority of farmers
who have the resources to invest in
mechanization, agrochemicals and
herbicide-resistant crop varieties.
However, if current trends continue
this will lead to increasing farm
sizes or consolidate cooperation
among large farms to justify the
investment in large-scale, expensive
machinery. An immediate thought
on this would be lamentations of,
‘The more things change, the more
they stay the same’, espcially given
the context of South African agriculture and its land reform efforts.
There are still some major impediments for this type of technology in
smallholder farms, which need urgent attention. Indeed, there is a