Farmers are being asked to manage their fertiliser use to reduce the build-up of cadmium in the country's soils.
The Ministry of Agriculture has released a national strategy to manage cadmium, a naturally occuring heavy metal which accumulates slowly in soils where there is regular use of phosphate fertiliser.
MAF senior scientist Dr Gerald Rys says concentrations of cadmium are relatively low in New Zealand's productive soils but monitoring shows those levels have slowly increased over the years.
He says while those levels do not present a health risk to humans, the strategy will ensure that soil and food are monitored and managed, so the situation stays that way.
Dr Rys says the strategy will be reviewed in seven years.