The Prince of Wales has urged people to buy British food to support family farms and help save the countryside.
Writing for Country Life magazine, Prince Charles said farmers made a "huge contribution" to the UK's "food security, environment and prosperity".
He said farmers and rural communities were facing a "grave situation" but added people "really can help by buying British food whenever we can."
The heir to the throne wrote the piece to mark turning 67 on 14 November.
He and the Duchess of Cornwall are currently on an official 12-day tour of New Zealand and Australia where they have visited a number of rural communities and met local producers.
In his article Prince Charles wrote: "On a sufficient scale the purchasing decisions of individuals can and do change markets."
He said buying British food meant customers were "more likely to be getting fresh, high quality produce from a known and trusted source, offering good value for money".
He added: "It seems to me that the key is to make it as easy as possible for people to know when they are buying British - and why that is a good choice."
The prince suggested many people were perhaps overlooking the importance of farmers to the UK.
"The rural economy is largely invisible to many people," he said. "So, it is perhaps worth spelling out, especially to those who - whether by choice or necessity - live largely urban lifestyles, that we rely on farmers to make a huge contribution to our nation's food security, environment and prosperity.
"And in all three respects, we live in an increasingly uncertain world. That is why we need to do everything we can to keep our farmers farming."
The prince concluded: "This may be considered merely romantic but, to me, our living, breathing, working countryside is one of the great glories of this country. I think we should treasure it, including its people, while we still can."
Mark Hedges, Country Life's editor, welcomed the prince's "romantic" view.
"There's nothing wrong with having a romantic view. It's not going to be particularly romantic when it's all gone," said Mr Hedges.
He added: "The prince has a powerful message where we can all make a difference. By buying British food, we will all be playing a vital part to safeguard the future of our precious countryside and everyone who works and lives in rural communities."