T Marandure and K Dzama
SU AgriSciences, Sustainable Agriculture group
What is sustainable agriculture?
The term sustainable agriculture has
increased in popularity over the past
decade. However, there are still varied opinions among researchers and
other technocrats on what really constitute sustainable agriculture. Essentially, sustainable agriculture is perceived to provide solutions to catastrophic challenges threatening current and future food production systems. The challenges include; environmental pollution from excessive
use of fossil fuels and agro-chemicals
including fertilizers, collapse of farm
economies due to rising costs of depleting fossil fuels and more toxic
chemicals needed to maintain
productivity. Other serious concerns
are related to food safety, animal
welfare and gender equality in labour, income and allocation of resources. In practice, sustainable agriculture conforms to the notion of
preserving natural resources for subsequent generations as defined in the
1987 Brundlant report on sustainable
development entitled ‘Our Common
Future’. Many definitions of sustainable agriculture exist in literature but
the following definition from the Sustainable Agricultural Institute (SAI)
will be used in this article:
“Sustainable agriculture adopts pro-
ductive, competitive and efficient
production practices, while maintaining or improving the natural environment and the global ecosystem, as
well as the socio-economic conditions of local communities”.
Clearly, the intentions of sustainable
agriculture digress from business as
usual. In principle the aim of maximising yields and economic returns
in conventional agricultural practices
is replaced by optimization of locally
available natural resources in sustainable agriculture. At the same time,
conserving or even enhancing the
natural resource base is key, while,
ensuring competitiveness, food security and high animal and labour welfare in agricultural production systems.
Sustainability monitoring
Sustainable agriculture risk being
meaningless if there is no monitoring
system to check the performance of
agricultural production systems. Unfortunately, amidst the academic debates on definitions or standard dimensions, farmers and other agricultural practitioners are keen to evaluate their production practices for sustainability. Admittedly, agricultural
systems are complex and diverse
which makes the use of a single blue
print for sustainability assessment
impractical. For this reason, there is
neither a universally accepted method of sustainability assessment nor a
method that truly claim to measure
sustainability with high degrees of
precision. However, there is consensus among researchers that selection
of certain appropriate environmental,
economic and social parameters can
give an indication of whether certain
trends are stabilizing, rising or declining. Thus, assessment of agricultural
sustainability is founded on simultaneously achieving the triple dimensions of environmental protection,
economic viability and social equity.
However, the appropriate indicators
used to measure each dimension are
not specified as they differ with location and production system, for example, nitrogen balance, would be
an important environmental indicator
in field crops but not so much in
greenhouses. Some commonly used
indicators are shown in Figure 1.
Indicated earlier, indicators are location specific, therefore, are best selected with the help of local farmers
and other stakeholder in the area.
Weights and reference levels of each
indicator are also defined by the
stakeholders with the help of relevant
experts. Finally each indicator is
measured and compared to predetermined reference levels. The methods
used to aggregate measured indicators vary. Some methods simply show
the operational levels of indicators
relative to their respective reference
values on a radial diagram. Other
methods are index based and compute weighted averages of each dimension before pooling an average
of the three dimensions into a single
index which will be used to assess
sustainability.
Are South African farming systems
trending towards or away from sustainability?
South African commercial crop producers are still heavily dependent on
the use of fertilizers and other agrochemicals to maintain yields. However, trends towards sustainability are
reported on a significant proportion
of the commercial grain, horticulture
and other crop producers that have
adopted some principles of conserva-