CA is characterized by three linked principles,
namely:
Continuous minimum mechanical soil disturbance.
Permanent organic soil cover.
Diversification of crop species grown in sequences
and/or associations.
CA principles are universally applicable to all agricultural landscapes and land uses with locally adapted practices. CA enhances biodiversity and natural biological
processes above and below the ground surface. Soil
interventions such as mechanical soil disturbance are
reduced to an absolute minimum or avoided, and external inputs such as agrochemicals and plant nutrients of
mineral or organic origin are applied optimally and in
Ample evidence now exists of the
successes of CA under many diverse agro-ecological conditions to
justify a major investment of human and financial resources in catalysing a shift, whenever and wherever conditions permit it, towards
CA. This will lead to large and demonstrable savings in machinery
and energy use and in carbon emissions, a rise in soil organic matter
content and biotic activity. It will
also reduce carbon emissions, ensure less erosion, increase crop water availability and thus resilience
to drought, improve recharge of
aquifers and reduce the impact of
the apparent increased volatility in
weather associated with climate
change. It will cut production
costs, lead to more reliable harvests and reduce risks especially for
smallholders. The latter point has
been the basis of the Low External
CA facilitates good agronomy, such as timely operations, and improves overall land husbandry for rain-fed
and irrigated production. Complemented by other
known good practices, including the use of quality
seeds, and integrated pest, nutrient, weed and water
management, etc., CA is a base for sustainable agricultural production intensification. It opens increased options for integration of production sectors, such as
crop-livestock integration and the integration of trees
and pastures into agricultural landscapes.
Photo: Hendrik Smith
No-till hand- and animal-drawn
no-till planters for smallholders.
Input
Sustainable
Agriculture
(LEISA) concept, which is critical for
household food security of around
3 million smallholder families in
South Africa. It simply means that
CA could sustain yields (and household food supply) on acceptable
high levels with a minimum
amount of external inputs, i.e. only
those who are accessible (available
and affordable) to smallholders.
that CA systems generate in terms
of yield, sustainability of land use,
incomes, timeliness of cropping
practices, ease of farming and ecosystem services, the area under CA
systems has been growing exponentially in many countries, largely
as a result of the initiative of farmers and their organizations. In
South Africa, CA is only now being
“mainstreamed” in agricultural development programmes, to be
backed by suitable policies and institutional support. Although the
total area under CA i s still small
relative to areas farmed using tillage, there is a significant upswing
in the number of innovative farmers (commercial and smallholder)
practising CA successfully, as well
as key research and development
initiatives promising significant
success in promoting it.
Because of the multiple benefits
Sunflower in oats residue.
Photo: FrancoisFouche
ways and quantities that do not interfere with, or disrupt, the biological processes.
No-till soyabeans in maize residues.
Photo: Andre de Villiers