Research

Planned, present and recently completed projects in universities, research institutes and industries.

University of Canterbury:

Biodegradation and composting profiles of woolscour wastes

Researchers: Steven Kroening and Laurie Greenfield (School of Biological Sciences, University of Canterbury) and Wendy Williamson (Landcare Research New Zealand Ltd).
Brief description: Composting of solid woolscour waste streams (chemically flocculated sludge and fibrous wastes) on both laboratory and pilot-plant scales as part of a total effluent treatment system to beneficially reuse all woolscour waste streams and prevent their disposal in landfills.
Status: Completed
Contact: Steven Kroening

Physical and mathematical modelling of the composting process

Researchers: Ian G. Mason and Mark M. Milke.
Brief description: A review of laboratory and pilot scale experimental equipment and currently available mathematical models is in preparation. Further developments regarding predicting composting activity for a range of raw materials, modelling natural convection and looking at bioremediation issues are under consideration.
Status: Completed.

Papers/reports:

• Mason, I.G., in press. Design and performance of a simulated feedstock for composting experiments.  Compost Science & Utilization.
• Mason, I.G., in press.  An evaluation of substrate degradation patterns in the composting process.  Part 1: Profiles at constant temperature Waste Management. (Published on-line 17 September, 2007).
• Mason, I.G., in press.  An evaluation of substrate degradation patterns in the composting process.  Part 2: Temperature-corrected profiles. Waste Management.  (Published on-line 12 September, 2007).
• Mason, I.G., 2006.  Mathematical modelling of the composting process: a review.  Waste Management 26(1), 3-21.
• Mason, I.G. and Milke, M.W., 2005. Physical modelling of the composting environment: a review. Part 2: Simulation performance Waste Management25(5), 501-509.
• Mason, I.G. and Milke, M.W., 2005.  Physical modelling of the composting environment: a review. Part 1: Reactor systems Waste Management 25(5), 481-500.

Contact: Ian Mason

Massey University:

Shredding of green waste using a crush/cut roller.

Researchers: Jonathon B. Hannon and Ian G. Mason.
Brief description: Green waste was shredded using a low cost crush/cut roller and a conventional counter-rotating shear shredder and composted in turned windrows. Initial particle size and bulk density differences found in material from the two systems, appeared to have no measurable affect on composting temperature profiles.
Status: completed.
Papers/reports: Hannon, J.B. & Mason, I.G. (2003) Composting of green waste shredded by a crush/cut roller vs a low speed counter-rotating shear shredder. Compost Science & Utilisation 11 (1), pg.61-71.
Contact: Ian Mason

Composting of high moisture dairy manure using passive aeration

Researchers: Ian G. Mason, M.Shahjahan Mollah, Ming Feng Zhong, and Graham J. Manderson
Brief description: Farm dairy yard manure was composted without prior dewatering in admixture with either sawdust or shredded paper, plus woodchips as the bulking agent, in a passively aerated pile. Thermophilic temperatures were maintained for up to 54 days, with final moisture levels ranging from 47-65 % (w/w).
Status: completed.
Papers/reports:

• Mason, I.G., Mollah, M.S., Zhong, M.F. & Manderson, G.J. (2004) Composting of high moisture content bovine manure using passive aeration. Compost Science & Utilisation12 (3) 249-267.
• Mason, I.G., Mollah, M.S. Ming Feng Zhong & Manderson, G.J. (2003) Using passive aeration in dairy waste treatment. Water & Wastes in New Zealand (129) 18, 20-23, May, 2003.

Contact: Ian Mason

HortResearch

Greenwaste compost as a component in soilless media

Researchers: Mike Spiers and George Fietje
Brief description: Greenwaste compost (GWC) was examined for its suitability as an ingredient in soilless media by measuring nutrient content, nutrient retention and physical properties. Growing media were formulated from GWC, composted pine bark and pumice, with suitable additions of lime and fertiliser. Nutrient concentrations, electrical conductivity and pH were measured in the media, which were used to grow tomato plants. Plant dry weight was used to assess media performance. Mixes with 30% (by volume) GWC, 50% composted pine bark, 20% pumice, 3 g/l dolomite lime and 3 - 4 g/l controlled release fertiliser performed as well as conventional bark-pumice mixes.
Status: Completed
Papers: Spiers, M. & Feitje, G. (2000) Greenwaste compost as a component in soilless media. Compost Science and Utilization 8, (1) 19-23.
Contact: Mike Spiers

Mulch for sustainable grape production

Researchers: Rob Agnew, Dion Mundy, Mike Spiers, Robert Hill, Tony Reglinski and Brent Clothier
Brief description: Mulches made from vineyard prunings, winery marc and combinations of other organic wastes such as greenwaste, bark, animal manures and mussel shells were applied to vines in four Marlborough vineyards. Soil physical, chemical and microbial properties, vine growth and yield, juice quality and disease incidence were monitored for three years. Mulch had either beneficial or neutral effects. Benefits included weed suppression, increased soil water capacity, increase in soil organic matter, nutrient input and buffering of soil temperature.
Status: Completed
Papers: Booklet "Mulch for Sustainable production" available from the Marlborough District Council.
Contact: Mike Spiers

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