The composting chickens of Koanga

Birds: 1 rooster, 8 hens Coop: 2.4m wide x 2.8m long, 6.72m² www.koanga.org.nz

Garden guru Kay Baxter of the Koanga Institute also uses her poultry as composters, but her system is more intensive.

The Koanga chicken coop is a small, covered, secure structure that sits above a 50cm-deep, tin-lined compost bin. There is a solid wall on the south side for shelter from the wind, and roosts and two nesting boxes sitting above the bin. A tray for dust bathing sits under the nesting boxes (to avoid poo contamination) containing wood ash and sand.

In autumn, four to six wool fadges of leaves are put into the bin to form the ‘floor’ of the run to a depth of 50cm. Kay uses leaves which are fast to break down and high in calcium and nitrogen, including poplar, willow, elm, cherry, maple and ash. Leaves to avoid are walnut and eucalyptus.

The poultry are free to walk and poop all over this thick layer of leaves which stays mostly dry through winter. Calcium is added regularly to balance the naturally high levels of magnesium found in chicken manure. Kay adds Nano-cal, a product made by Environmental Fertilisers, but alternatives include garden lime, burnt bones or crushed egg shells.

In spring she uses a fork to turn it over. It turns into compost quite fast after this, and she then uses it in her garden beds.

During the rest of the year the poultry help to compost all the green waste from the garden. Worms from her vermicomposting system which sits beside it are added to provide food.

Kay adds carbon to keep it healthy, using tagasaste (pre-chewed by her rabbits which are in cages alongside the coop, or you can use a mulcher) and other carbon crops.

Grains are spread over the compost to encourage the flock to turn it over. Kay also has a grain mix, a poultry mineral mix, seaweed meal and soldier fly larvae available, plus fresh, clean water.

Kay adds carbon crops to create a balanced compost