The Prince of Wales has spoken of his excitement at the prospect of bonding with his first grandchild.
The Duke and Duchess of Cambridge are expecting their first child in July.
Charles said of becoming a grandfather: "It's a lovely thought and I look forward enormously to that relationship."
The Radio Times said that he admitted the prospect made him feel old and that he expressed concern about the land his grandchild would inherit.
"We need to think about the future, we need to think what kind of world we're handing on to our successors," Charles told a special 25th anniversary edition of BBC One show Countryfile, which he is guest editing.
"If you think of it in those terms it should make us reflect on the way we do things so we don't ruin it for them."
He warned: "That's why it's so important to work in harmony with nature rather than thinking we can somehow ignore, dominate, separate ourselves from nature, because unless we pay our respect to nature, she's a great deal more powerful than we are."
Charles also spoke of his love of walking, saying: "Walking is a terribly important thing for me. Rather like some people need a cigarette, I need a walk.
"I find it stimulates the thinking and the reflecting. I spend my life stamping about and I have, you know, things I write down. That's where the best thoughts come from."
Countryfile presenter Adam Henson, who farms about 30 miles from the Prince's Tetbury estate, said: "The Prince ... has concerns about the amount we rely on pesticides and fertilisers. Personally, I couldn't manage without artificial fertilisers...You need to weigh up the most profitable way of farming. It's horses for courses. There's no right or wrong."