THE NSW Farmers Association has stepped up its action against the coal seam gas industry, calling for landholders to be granted rights to stop drilling companies entering private land.

The State's peak farming body has challenged the industry to prove it will not damage agricultural water supplies, and called on companies to disclose the chemicals they use during fracking, on a public register.

NSW Farmers president, Fiona Simson told the Herald "Farmers think that any impact on farm operations is too much impact. Anything that can't be fully mitigated is just not acceptable."

The association said its submission represented the views of most NSW food producers.

The possible contamination of underground aquifers by fracking, also known as hydraulic fracturing which involves pumping a mix of water, sand and chemicals underground to force more gas out of wells, is their main concern, Ms Simson said.

Several drilling companies are proposing thousands of gas wells, the association believes, and its submission argues that the cumulative effects will lead to a significant portion of the state's fresh water being diverted to industrial purposes.