Chemistry Reference
In-Depth Information
sustainability indicators, which could be physical, chemical, biological,
economic, social or other. The identification of suitable indictors for soil is
complicated by the multiplicity of physical, chemical and biological factors
that control biogeochemical processes and their variation in intensity over time
and space.
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A set of basic indicators of soil changes has not been defined,
largely due to the range across which soil properties vary in magnitude and
importance. Pedotransfer functions can be used to estimate soil attributes that
are lacking; for example, the CEC can be estimated from the clay content and
type, and the organic C content.
Agricultural decision-making will not and does not need to await the
rigorous development and endorsement of a full framework that incorporates
all of the determinants of sustainability, such as standards, indicators, criteria
and threshold values. Analyses often reveal that some, but not all,
sustainability requirements are met and hence a system can be evaluated as
''partially'' or ''conditionally'' sustainable. Being able to track the general
process towards the goal may be more useful than setting specific, rigid targets
to be achieved.
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This seems a useful alternative to the Framework for the
Evaluation of Sustainable Land Management (FESLM) approach. There is a
whole range of new observational and measurement techniques in soil
science
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that will greatly facilitate the evaluation and reporting of soils in
sustainable agriculture and food systems.
In discussions of agricultural sustainability, it is our contention that we are
at a critical inflection point with respect to the objective approaches to describe
the consequences and implications of agricultural practices on soil. We have
reviewed standards where Tier 1 sustainability is measuring parameters of
importance in diverse, robust, resilient agricultural systems that adequately
provide food for future human populations. In general, these approaches still
fall short of moving agriculture from a fundamentally extractive process to one
that is fundamentally regenerative and restorative for soil resources. Tier 2
sustainability requires, however, a commitment to reduce the environmental
footprint and improve outcomes in human dimensions. At present, many
businesses and organisations have begun to use ''corporate sustainability'',
''green strategies'' and the concept of ''continuous improvement'' and
therefore are transitioning into this second tier of sustainability. There is
concern that performance of agricultural systems is profoundly discontinuous
and, in the face of climate change, shows more variability, especially across
dimensions of time and space. As such, we propose the concept of Tier 3
sustainability, whereby we commit to actions, recognising local-to-global
continua that will move us, in aggregate, into planetary safe space with respect
to outcomes in human, environmental and ecological dimensions.
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In this tier,
the commitment is to move toward agricultural systems that are fundamentally
regenerative, consistent with practices that could be used over millennia with
steady or improving productivity.
In this chapter, we have summarised some of the current approaches in the
USA and global sustainable agriculture regarding soil attributes and practices.
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