More than 350 farmers have voted in support of prohibiting mining and CSG activities on areas considered to be prime agricultural land at the NSW Farmers' Annual Conference in Sydney.

NSW Farmers' President-elect and Mining Chair Fiona Simson says there was an urgent need to strengthen the Association's position.

"The message we're hearing from farm families and regional communities is loud and clear. They are no longer willing to tolerate their rich, fertile soils being dug up at the whim of a mining or CSG company.

"High levels of community concern about the scale and intensity of existing mining activities in areas such as the Gunnedah Basin and the Hunter Valley has presented NSW Farmers' with an opportunity to bolster its approach to the issue," she said.

"We are not opposed to mining but we do believe there should be limitations on where it can take place," she said.

NSW Farmers' defines 'prime agricultural land' as productive agricultural land and water resources that are finite, and must be conserved and managed for the longer term.

Prime agricultural land is also important to Australia's contribution to protecting global food security. The United Nations estimates agricultural production must grow by a massive 70 percent by 2050 to feed an additional 2.6 billion global citizens.