Dung Beetles Help Improve Soil Health
Discover how dung beetles are being used to improve soil health and replenish New Zealand's pastoral land.
The non-partisan Dung Beetle Innovations group (DBI) have introduced their newest species of dung beetle into New Zealand from Western Australia.
The eggs of Onitis alexis arrived at Landcare Research’s Tamaki quarantine facility on March 3rd amidst much excitement.
Principle Scientist on the project, Shaun Forgie says “introducing Onitis alexis is an important step in enhancing the sustainability and health of New Zealand’s soil and water quality.
“New Zealand’s 15 species of native dung beetles are primarily forest dwellers and are rarely seen venturing from forest margins into exotic pastures to utilise and break-down livestock manure.
“Introducing dung beetles to break-down manure is essential for achieving sustainable farming production in the future. They are a natural way to protect the environment, waterways and increase pastoral activities for farmers. The long-term benefits are huge.”
New Zealand’s present farming economy is founded on introduced organisms. In the 1880s, early settlers brought livestock such as cattle, deer, sheep (and the grasses on which they fed) to New Zealand, establishing today’s British inspired pastoral farming systems. However they failed to introduce organisms that could quickly and efficiently dispose of the manure the animals generated.
Every day New Zealand’s estimated nine million cattle drop 180,000 tonnes of manure, making up to 950 hectares of prime pastoral land unusable. Over time, the slow accumulation of manure contaminates waterways and reduces the amount of forage available for grazing.
Exotic pastoral earthworms were originally introduced to break down manure, but they were inefficient as it took a long time for earthworm numbers to establish in areas with suboptimal pH levels.
Dung beetles are a natural and more efficient disposal tool. Both organic and non-organic farms can benefit from dung beetles working on their properties.
The beetles make tunnels up to 90 centimetres below the earth’s surface. Most have evolved to feed and breed exclusively in manure. They break down the faeces of grazing mammals and bury it in the tunnels for their young to feed and develop within. Where dung beetle populations are established and thriving, they can remove fresh manure within days.
In June 2010, the Dung Beetle Release Strategy Group (which Dung Beetle Innovations was founded) applied to the Environmental Protection Authority to release eleven species of dung beetle throughout New Zealand. Permission was granted in February 2011 after rigorous testing.
The Ministry of Health and Landcare Research assessed the programme for risks to human health. Their findings agreed that in areas where dung beetles became abundant, their activity will decrease the transport of pathogens from ruminant dung on pasture, to people. Essentially, it is better for human health to bury manure rather than leave it on the surface.
Onitis alexisis Spring and Autumn active. In the coming months, Dung Beetle Innovations will introduce more eggs of Onitis alexis as well as Copris hispanus and Bubus bison.
Shaun Forgie says that “no one species can be expected to do the whole job. Each species thrives in different conditions and temperatures. Eleven different species in total have been chosen to make sure there is a 24/7 dung beetle presence throughout the year.”
Five species of dung beetle have now been released on both BioGro certified properties and non-organic properties. It is not yet decided where Onitis alexis will be released after they have been mass reared and cleared by quarantine.
The introduction of dung beetles to New Zealand is a long-term project. It has been incredibly successful overseas and Shaun Forgie expects a similar positive outcome for New Zealand.
Contact: Shaun Forgie (firstname.lastname@example.org)