A Guernsey politician has urged the island to follow Jersey in safeguarding farmland for agricultural use only.
Deputy Janine Le Sauvage said she was concerned that fields used for crops and cattle were being lost and used instead for gardens or grazing horses.
She said: "I know of an instance where a farmer lost a large field because a horse owner came along and offered the landowner five times the annual rent."
Farmers have claimed to be losing up to 300 vergees (122 acres) every year.
Deputy Le Sauvage said farmers rarely owned their own land and could not match the sums being offered by horse owners.