Conservation Agriculture and soil
fertility management
Part 1:
Theoretical principles and practices
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Hendrik Smith, Conservation Agriculture Facilitator,
Gerrie Trytsman, Independent Scientist,
Grain SA
n South Africa, crop production systems
based on intensive and continuous soil
tillage have led to excessively high soil
degradation rates with a reduction in
natural soil fertility in areas under grain
production. It also results in the consistent
recommendation of the use of huge quantities
of chemical fertilizers that are biologically
unnecessary, economically extravagant and
ecologically damaging. Tillage results in the
oxidation and destruction of carbon in the soil
by increasing the soil oxygen levels, thereby
promoting bacteria populations to expand and
consume active carbon in the soil. Soil organic
carbon (SOC), or soil organic matter (SOM), is
the key element that drives soil health, which
in turn is the primary factor having an impact
on sustainable crop production. If sound
farming practices are sustained over time,
soil health improvement could significantly
escalate, influenced by positive changes in a
wide spectrum of soil parameters, including
soil fertility, which then result in improved
productivity and profitability of farming
systems.
There is general agreement among key
stakeholders in South Africa, that soil health
and sustainable crop-livestock production will
only be achieved through the adoption and
implementation of Conservation Agriculture
(CA) principles and practices. CA is seen as an
ideal system for sustainable and climate-smart
agricultural intensification and regeneration,
through which farmers can attain higher
levels of productivity and profitability, while
improving soil health and the environment.
Photo 1: Crops can be planted into crop res-
idues without physically disturbing the soil
AgriKultuur |AgriCulture
One of the good agricultural practices (GAPs)
associated with CA is integrated soil fertility
management (ISFM), which essentially
depends on locally adapted CA principles
and practices to build-up soil health, allowing
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