Farmland is being swallowed up by urban development as the populations of Auckland, Hamilton and Tauranga grow.
Between 2001 and 2016, about 10,000 hectares of horticultural land was lost, said Horticulture NZ chief executive Mike Chapman. Sixty per cent of that was in vegetable production and the remainder produced fruit.
"There are areas where we should be directing houses and areas where we shouldn't be directing houses and we should do a lot more planning for it," Chapman said.
"We need a national food security policy, focused around vegetables and focused around our being able to feed ourselves and protecting the land that feeds us."
Horticulture NZ has been pushing its food security agenda for several years, Chapman said. Prior to the election, it released a manifesto calling for better protections of high-quality growing soils and in 2016, it made a submission to the National Policy Statement on urban development highlighting the threat to food production.
More than 50 percent of New Zealand's population lives in Auckland, Waikato and the Bay of Plenty. That's expected to grow to more than 70 per cent.
It also makes up a significant part of food production, especially at Pukekohe, just north of the Waikato border, where soil quality is high and there's a climate that allows for year-round vegetable growing.
The population there is expected to double in the next 30 years.
"They grow our spring vegetables, not just for Auckland, but for all of New Zealand," Chapman said.
"If there are houses planted in Pukekohe instead of vegetables, we'll be importing them. That's what we are really talking about ... which is crazy."
City expansion is also putting pressure on agricultural workers who are now struggling with home affordability, especially in Auckland, and with the cost of travel.
"The further they are away from town, the harder it is for workers to get there and the less chance there is for workers," Chapman said. "It puts a real constraint on your ability to get high-quality labour if they have to travel a long way."
Federated Farmers' Waikato provincial president Andrew McGiven said urban developing takes land out of the production cycle forever, forcing farmers and growers on to less arable soils.
"Once you get houses on it, that's it," McGiven said. "It's going to be an never-ending squeeze."
In Waikato, the inter-agency Waikato Plan document included retention of quality soil as an issue. About 13 per cent of the Waikato - about 300,000ha - is high-quality soil.
Hamilton, Waikato and Waipa councils have partnered with a Future Proof plan to ensure productive farmland isn't gobbled up as the population looks to double in the next 50 years.
"There will come a point where land is so scarce that you can't do the historical production that's been done and that's going to be a real question for the community and the economy," McGiven said.
"Do we carry on urban sprawl or do we start looking at safe-guarding our productive land?"
Hamilton Deputy Mayor Martin Gallagher agreed planning is needed.
"In Britain, you still have lovely rural villages where the houses have great rural outlooks, but around them is productive farmland," Gallagher said.
"In New Zealand we have a very bad situation where we have gone on for a series of lifestyle blocks. Some are productive, but to me, we've got to be extremely careful we don't continue to gobble up productive land.
"You can have a win-win, but we have to be extremely careful."
Waikato Regional Council chairman Alan Livingsto said there is no simple solution.
"We are not looking at the big decisions," Livingston said. "While it is all very well to encourage urban development, we are losing hundreds of hectares of high-producing land each year.
"We have to find land for residential development and the only land logically available is high-producing stuff."