"I've been through the biodynamic certification process myself and this spiritual aspect has been missing. There's still a need to be mindful about what you use, where you use it and how you use it.
"Our vision is to have all Maori land with a sign saying Hua Parakore at the gate."
Bee keeping and pollen enterprises and a Palmerston North dairy foods company, farmers, commercial growers and other land users had signed up to it.
While producers were increasingly meeting consumers' need for uncontaminated food, Hua Parakore was also against the hybridisation or modification of old plant varieties.
Ms Hildreth said Maori gardeners were aware of the need to protect old varieties of riwai and other plants.
But iwi had deep concerns about the health and treatment of the whenua (land), she said.
The lack of a Northland-wide local-government block on genetically modified organism trials breached partnership principles, Ms Hildreth said.
Issues such as fluoride in public water supplies were also of concern.
"The bulk of the water that goes into our homes goes down the drains ... We only drink a very small amount of it, so give people fluoride pills - don't put a chemical into the water that ends up in our whenua."
Chemicals that went into the earth stayed there and undermined food producers' ability to say their soil and products were uncontaminated.