(WALI) system https://www.daf.qld.gov.au/environment/ag-land-audit/web-map
ping-tool). Determining which policy position to adopt (closed-loop agricultural
and nutrient cycles versus bioeconomy utilisation) is a trade-off which is unique
for every waste stream, nutrient and technology application. All factors must be
considered and analysis of whole of life impacts is essential. For example, new
business ventures are utilising sugarcane trash as a commercial product, bagged and
supplied to the gardening sector as a mulch. Whilst the collection and value-added
process of sugarcane trash provides direct financial value to the farmer for a
‘product’ which, at face value, is a waste product, the loss of the nutrients (carbon)
contained in the trash from the soil is a loss from the agricultural cycle. Ward et al.
(2016) note that it is necessary to consider whether more value can be extracted from
the unwanted (or unvalued) resource streams (e.g. protein or energy) and whether
doing this interferes with nutrient and carbon cycles.
8.12 Discussion
There is increasing global concern and opposition to the spreading of mixed waste
composts, compost-like organics (CLOs), stabilised wastes, manures and untreated
biosolids to land, in particular to farmland. This has resulted in some jurisdictions
setting high-quality standards for both organic waste treatment processes, and the
resulting organic products and land/plant application limits, whilst others have
moved to ban the application of mixed waste composts and CLOs to farmland.
Concerns regarding the land application of these products include the impacts of
physical pollutants such as glass and plastics, biological factors including pathogens
and genetically modified organisms, animal diseases, the toxicity of heavy metals
and, more recently as highlighted in the literature (Browne et al. 2011; van
Cauwenberghe and Janssen 2014; Weithmann et al. 2018), the bioaccumulation of
persistent organic pollutants and micro-pollutants. The early ‘shred and spread’
applications of wastes and untreated organics to land were driven by the desire to
avoid increasing waste disposal charges, often as a result a waste and/or landfill tax.
In these cases, many environmental regulatory authorities were slow to realise the
loopholes, determine environmental harm and, in turn, control application or specify
application rates. In many cases application rates were decided by farmers and, in
some cases, the market value (or free of charge nature) of these products against the
increasing price of traditional chemical fertilisers. It is also easier to define and prove
environmental benefit than environmental harm, particularly where soils are weak or
deficient in a range of nutrients or organic matter. As such, mixed waste composts
and CLOs, in many cases, are able to easily demonstrate their beneficial application
(as they do provide potassium, phosphorous and other nutrients as well as carbon),
particularly in comparison to single stream (green waste) composts, whilst the
contamination risks are harder to define and more expensive to prove. This is
particularly true for the cost of analysis to identify micro-pollutants and the required
commitment of undertaking longitudinal surveys to determine the risks of
138
G. Davis
ping-tool). Determining which policy position to adopt (closed-loop agricultural
and nutrient cycles versus bioeconomy utilisation) is a trade-off which is unique
for every waste stream, nutrient and technology application. All factors must be
considered and analysis of whole of life impacts is essential. For example, new
business ventures are utilising sugarcane trash as a commercial product, bagged and
supplied to the gardening sector as a mulch. Whilst the collection and value-added
process of sugarcane trash provides direct financial value to the farmer for a
‘product’ which, at face value, is a waste product, the loss of the nutrients (carbon)
contained in the trash from the soil is a loss from the agricultural cycle. Ward et al.
(2016) note that it is necessary to consider whether more value can be extracted from
the unwanted (or unvalued) resource streams (e.g. protein or energy) and whether
doing this interferes with nutrient and carbon cycles.
8.12 Discussion
There is increasing global concern and opposition to the spreading of mixed waste
composts, compost-like organics (CLOs), stabilised wastes, manures and untreated
biosolids to land, in particular to farmland. This has resulted in some jurisdictions
setting high-quality standards for both organic waste treatment processes, and the
resulting organic products and land/plant application limits, whilst others have
moved to ban the application of mixed waste composts and CLOs to farmland.
Concerns regarding the land application of these products include the impacts of
physical pollutants such as glass and plastics, biological factors including pathogens
and genetically modified organisms, animal diseases, the toxicity of heavy metals
and, more recently as highlighted in the literature (Browne et al. 2011; van
Cauwenberghe and Janssen 2014; Weithmann et al. 2018), the bioaccumulation of
persistent organic pollutants and micro-pollutants. The early ‘shred and spread’
applications of wastes and untreated organics to land were driven by the desire to
avoid increasing waste disposal charges, often as a result a waste and/or landfill tax.
In these cases, many environmental regulatory authorities were slow to realise the
loopholes, determine environmental harm and, in turn, control application or specify
application rates. In many cases application rates were decided by farmers and, in
some cases, the market value (or free of charge nature) of these products against the
increasing price of traditional chemical fertilisers. It is also easier to define and prove
environmental benefit than environmental harm, particularly where soils are weak or
deficient in a range of nutrients or organic matter. As such, mixed waste composts
and CLOs, in many cases, are able to easily demonstrate their beneficial application
(as they do provide potassium, phosphorous and other nutrients as well as carbon),
particularly in comparison to single stream (green waste) composts, whilst the
contamination risks are harder to define and more expensive to prove. This is
particularly true for the cost of analysis to identify micro-pollutants and the required
commitment of undertaking longitudinal surveys to determine the risks of
138
G. Davis