Whether agriculture comes into the emissions trading scheme (ETS) in 2015 or not will depend on technological advances and what other countries do, Climate Change Minister Nick Smith says.
NZPA reported last month comments Agriculture Minister David Carter made in a memo saying the government was open minded about future inclusion of the sector.
Agriculture is not set to be included in the ETS until 2015, while transport fuels, electricity production and industrial processes will be included from July 1.
Under a heading "agriculture's inclusion," Mr Carter said the government was "keeping an open mind, will remain flexible and are watching international developments closely."
Reviews around agriculture's entry into the ETS are planned for 2011 and 2014.
"These reviews are an opportunity to look at what our trading partners are doing. For example if major trading partners such as Australia have made no progress on their schemes, the government would have to seriously reconsider including agriculture from 2015."
Dr Smith told TV One's Q&A programme that Mr Carter was "absolutely" right.
He said including agriculure depended on two key things.
"First, I want some technology that farmers can practically use to reduce their emissions, that's why we've got a huge initiative around the Global Research Alliance on agricultural emissions.
"The second issue for New Zealand is about the progress that's being made with the Australians, with the Americans, and other countries, because there's no point in disadvantaging the New Zealand farmer only to have the agricultural production to feed the world occurring in other parts of the world where they produce more emissions."
Dr Smith previously said the scheme would not be credible without agriculture's inclusion.
He said farmers were already included in terms of costs from electricity and fuel from July 1.
"The key difference, and we can go back to the time when there was that strong farmer revolt to what became known as the fart tax, New Zealanders I think felt that was a bit unfair, you're picking on farmers by themselves, they were the only ones that were going to pay it.
"With this, what we're doing in government today is actually whether it be businesses, whether it be household, whether it be farmers, they're all asking to make a contribution towards reducing those emissions."