Environmental regulators are calling for public comment on a plan to import and release dung beetles to improve soil health, reduce the run-off of animal waste, and reduce nitrous oxide emissions.
Scientists were last year given $400,000 in taxpayer funding to investigate the use of the beetles, and now the Environmental Risk Management Authority (Erma) is calling for submissions on an application to import and release up to 11 species.
The Dung Beetle Release Strategy Group -- made up of farmers and other interest groups and funded through the Ministry of Agriculture and Farming -- has said the beetles will reduce greenhouse gas emissions from cattle dung by burying it and then using it as a food source and breeding site.
Submissions close on November 4.
Scientists have predicted successful introduction of the beetles would one of the biggest changes to farm management since cows first arrived here.
Strategy group chairman John Pearce said sheep, cattle, deer, goats and other domesticated livestock had been brought to New Zealand without the beetles that naturally processed their dung, and at least 5 percent of the nation's pastoral farmland is covered in cattle dung at any one time.
``Depending on the time of year and climate, it may take dung pats up to six months to break down,'' he said. The contamination reduced the amount of forage available for grazing.
In addition to improved water infiltration and reduced flooding, the beetles could also slash nutrient runoff and waterway pollution, reduce reinfection of livestock with parasitic worms, boost earthworm populations, and forage plant growth, and reduce the incidence of infective stages of livestock diseases in pastures.
``The benefits of this application are considered to outweigh the risks'' he said.
No significant adverse environmental effects were expected, as native dung beetles only lived in deep forest, while the introduced beetles would be limited to open grassland.
Adult dung beetles bury animal dung and lay their eggs in it, and the grubs feed on the dung -- effectively spreading the dung under the soil.
The beetles are expected to be bred up to sufficient numbers to be released in three years, initially in the Rodney district, north of Auckland, followed by releases through all parts of the country.
An earlier attempt to introduce dung beetles was made in the 1990s - before Erma was established - but was rejected by regulators at the time.