The Green Party is promising to give farmers $297 million to help them transition to climate-friendly practices, but its "Farming for the Future" agriculture policy has not been met with much enthusiasm from the rural community.
A proposed levy on nitrogen and phosphorous fertilisers was of particular concern.
The levy will be 2c per every kilo, which the Greens claimed would cost the average dairy farm $1515 annually.
The Greens also want to overhaul of the Organics Bill, a move welcomed by organic growers, but labelled "a slap in the face" for farmers by National Party agriculture spokesman, David Bennett.
This didn't mean that all of New Zealand's agriculture would go organic or regenerative, but those sectors needed support, as they were more lucrative markets, Shaw told The Country's Jamie Mackay.
"If you look at our overseas markets, the brand value that people attach to labels that are regenerative, organic or sustainable in some way, attract real premium prices."
Shaw said he was not concerned by fears that organic farming reduced production by as much as 30 per cent, as this would be offset by these increased prices.
"The markets that we're selling into overseas are many, many times larger than New Zealand. There are well north of 40 million consumers around the world who are quite prepared to pay significant prices for the best food in the world. Which is what we're offering.
He also denied that the Greens wanted an outright ban on chemical fertilisers.
"We want to reduce the rate of use of artificial fertilisers. The rate that was set is quite high above the national average and significantly higher than some of our competing markets. I think if we do put a sinking lid on that then it will drive more innovation and use of other ways of fertilising that don't have such negative consequences."
While Shaw couldn't provide any alternatives off the top of his head, he said he had heard some success stories from organic farms in New Zealand.
"If you go and look and talk to some of the organic or regenerative farmers around, then there are options that they are using where they're saying actually we're getting healthier soils, healthier water and higher quality product that we're able to sell for a premium price and we haven't had to use nitrogen fertilisers for some years."
There was one product that the Green Party wanted "gone" from farming - palm kernel expeller (PKE), which is used in stock feed. PKE is a by-product of the palm oil industry which has been linked to the destruction of rainforest in places like Indonesia, Shaw said.
"I think most Kiwi farmers would be horrified to think that they were in some way responsible for the extinction of the orangutan."
Also in today's interview: Shaw answered farmer's questions on his policies, including what kind of research had gone into regenerative agriculture and why greenhouse gas emissions calculations for agriculture didn't include offsets.