Poultry waste fuels expanded composting operation in Matamata region
The ability to turn highly putrescible poultry processing waste into nutrient-rich compost via a safe and efficient composting process underpins a new development at the Tirohia landfill site.

Who are we?
Tirohia Compost Solutions Ltd is a 50:50 joint venture company between H.G. Leach & Co Ltd from Paeroa and Bigham Holdings Ltd from Matamata. We operate a composting facility at Tirohia, transforming by-products from the poultry industry and green waste into high organic matter and nutrient-rich compost.

Composting process
Tirohia Compost operates vertical composting units (VCU). These are in-vessel, computer controlled continuous-flow composting systems that achieve high temperatures for rapid stabilisation of feedstock. The site utilises poultry processing waste and local greenwaste to produce a high organic matter and nitrogren, calcium, and phosphorus-rich product.

Environmentally consciousTirohia Compost helps the local area by not only producing a high quality compost, but by composting these poultry industry by-products, significant reductions in landfill volumes are achieved.

Practical experience
Matamata dairy farmer, Kerry Simpson, has applied 2.5t/ha of compost to part of his farm over the past two years. His milk solids production has increased 9% to 1,200 kg/ha which Kerry largely attributes to the compost application. During the 2005 dry summer the compost treated paddocks held on better and an extra grazing was obtained from them, “the compost paddocks didn’t look as stressed as the urea treated paddocks which received a ‘hit’ of nitrogen.” Tirohia Compost Solutions Kerry’s cows eagerly await another ration of compost enriched pasture.

Research studies
AgResearch is monitoring a series of paddocks on Mr Simpson’s farm that have received either: 0 t/ha, 2.5 t/ha, or 10 t/ha of compost. Initial soil sampling six months after application revealed increasing levels of Total Nitrogen, Olsen Phosphate and Cation Exchange Capacity with increased compost rates.

Recommended application rates:

Fine screened compost (< 40mm)
Dairy farms Forestry-to-dairy conversion Horticulture Cropping (Maize)	2.5t/ha 5-10t/ha 10t/ha 10-20t/ha

Unscreened coarse compost (> 40mm) is suitable for use as mulch, particularly in horticultural applications.

Compost analysis (typical concentration range)

Measurement	(%)
Dry matter Organic matter Nitrogen Phosphorus Potassium Calcium Magnesium Sodium	50 - 60 40 - 45 0.7 - 1.2 0.30 - 0.65 0.15 - 0.35 1.90 - 5.50 0.11 - 028 0.09 - 0.16

A typical trace element analysis is available on request

For a free quote on pricing
please provide information on: 1) area to be spread, 2) distance from composting plant, 3) type of farm, to Craig on 021 952 768 or Steven by email at steven.hill@hgleach.co.nz.

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The Vertical Composting Unit (VCU) is an enclosed aerobic composting system suited to processing biological waste in small to medium sized municipal and industrial applications.

The brilliance of the VCU system lies in its simplicity

Composting takes place inside modular chambers, 25 cubic metres in capacity. Processing is continuous with waste being loaded into the top of the chamber and stabilised product removed from the bottom every day.

The unique vertical orientation of the processing chamber enhances a natural process. Aeration is provided by natural convection forces that are accelerated by a fan mounted on top of each chamber. Odour control is by way of self-biofiltration and leachate is not produced.

The result is a system that is elegant in its simplicity, offering very low operating costs due to low energy, maintenance and labour requirements.

 

Download the
Compost Trial Info here

 

Barry operates the Tirohia plant.