9 June 2005
Australian Compost Standard to be Adapted for NZ
Most New Zealand gardeners associate compost with either a compost bin lurking in a quiet corner of the garden waiting for contributions - the odd banana skin and results of the weekend’s deadheading - or putting their backs out lugging bags of dark, rich compost up the steps having visited the local garden centre.
Now think of composting on a far greater scale – masses of green waste with potential to produce high quality bulk compost suitable for commercial application.
In 2003, the Ministry for the Environment (MfE) accepted responsibility for the implementation of a Waste Strategy, a framework for addressing how New Zealand can minimise and manage waste. Current organic waste levels in landfills are estimated to be 30-40% of the total landfill weight and 26% of New Zealand’s total waste output. The waste produces leachate and generates methane, a greenhouse gas.
As part of its effort to gain input into how to reduce organic waste levels by diverting waste from landfills to beneficial use, the Ministry assembled a stakeholder group. This group then requested that a New Zealand Standard be developed for compost.
After considering many possible contributions to MFE’s objectives, including overseas standards and those used by parts of New Zealand industry, the group has concluded that an adoption of the Australian Standard AS 4454:2003 Composts, soil conditioners and mulches, with amendments will suit the New Zealand requirement. A draft has been produced which marks up suggested changes.
The Standard will be published as NZS/AS 4454, and will be applied on a voluntary basis. It may eventually form the basis of a certification scheme.
AS 4454 specifies physical, chemical, biological and labelling requirements for composts, mulches, soil conditioners and related products. It applies to a variety of organic products and mixtures, mainly for industrial use, but specifically excludes home composting products, organic fertilizers such as blood and bone, and some plastics materials used as compost starters and activators. Shredded grass and biosolids are also outside the scope of the Standard.
“It’s all about having confidence in the consistency of the product,” says Lesley Valentine, Business Relationship Manager at Standards New Zealand, “and on a commercial scale it’s a very long way from backyard production and a wide range of organisations and businesses will benefit from adapting the Australian Standard for New Zealand use.”
The Standard is mainly intended for use by local government, and manufacturers and suppliers of compost, mulches and soil conditioners. Experience in Australia has shown that use of AS 4454 standard compost or mulch gives many benefits, including:
- Increased water retention and penetration of soils (so less irrigation is needed)
- Less need for chemical fertilisers and other additives
- Improved resistance of plants to disease or fungal problems
- Reduced erosion
- Better nutrient retention in the soil
The Standard is expected to be published late 2005.
Stakeholder groups involved in the project include:
- Landcare Research
- HortResearch
- Perry Enviornmental
- Living Earth
- Earth Maker
- Rural Supply technologies
- Local Government NZ/Regional Council
- Timaru City Council
- Wellington City Council
- Christchurch City Council
- Nursery and Gardens Industry Association
- Fonterra
- Heinz Watties
- NZLIA
- Composting NZ
- MfE
- Vermacast NZ
- Biogrow
- Agriquality
- Massey University
- Maori Organics Group
- NZ Wate and Water Association
- NZ Waste Management Institute