A farming campaign group took their tractors to the centre of Truro for a protest on Saturday.
Farmers Movement Cornwall organised a rally to raise awareness of how the public can support British produce, and also to highlight issues over food security.
The rally, which began at at 12:30 GMT in Victoria Square, was also sparked by the debate over changes to inheritance tax laws.
Peter Lawrence, one of the organisers, said he thinks there is not enough home-grown food produced in the area.
He said: "We want to make the public and government aware of our concerns regarding food security.
"We shouldn't be so heavily reliant on imports, we should be more self-sufficient and agricultural policy should change to ensure maximum agricultural self-sufficiency."
Mr Lawrence added: "The inheritance tax issue is very important and has triggered a lot of concern amongst the farming community.
"Farmers are very concerned and it certainly is one of the issues that sparked the protest today."