The Rabbit Island Biosolids Project

Authors: Peter Wilks, Hailong Wang
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2009, Issue N.Z.J.For. 54(2) 2009, pp 33-36, Aug 2009
Publisher: New Zealand Institute of Forestry

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Abstract: Biosolids from the Nelson regional wastewater treatment plant have been applied to a 1000-ha Pinus radiata plantation at Rabbit Island since 1996. Rabbit Island (Moturoa) is Crown Land that was vested to the Waimea County Council, now the Tasman District Council, in 1920 as a reserve. In addition to the plantation area, there is 300 hectares of recreation reserve. The Island is very flat (maximum altitude 10m) and is made up of predominantly Tahunanui Sand soils with naturally low nutrient and organic levels. The lack of nitrogen in particular, greatly limits Radiata Pine growth. Organic material is almost absent from soil profiles due to previous burning practices for re-establishment. The soils are permeable and provide free root access to the shallow ground water levels which are between 2 and 4 meters below the surface. Annual rainfall is around 900mm. The island is a very popular recreational asset with some of Nelsons finest beaches and is visited by around 150,000 people per year. Forestry activities are also very important and currently there is a sustainable cut of 20,000 tonnes per year which provides a significant source of income to the Tasman District Council to off-set rates.

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