Uncertainty over the NSW government's changes to land-clearing laws that would allow individual farmers to bulldoze native vegetation areas equal to 330 times the size of the Sydney Cricket Ground continues to fester, with the peak farming body saying many landholders may not participate in the scheme.

The government has released proposed new codes for land clearing for public feedback that will allow some farmers to remove as much as 625 hectares over three years.

The codes - which are yet to be backed up by vegetation maps showing the areas where farmers will be permitted to make their own assessments - remain too onerous and "riddled with red lights", said Mitchell Clapham, conservation chair at NSW Farmers.

"We can't agree that it is fair to require farmers to set aside half or more of the vegetation on their own property, and undertake yearly reporting, forever," Mr Clapham said. "At the moment the settings aren't quite fair and we believe many farmers will not engage or participate in a system that is over-regulated, complicated and riddled with restrictions."