The Saunders' sheep and beef farm at Glen Oroua, near Palmerston North, goes back five generations.
Past and present family members play a large role in "Under a Big Sky," especially Saunders' farming father.
"Dad's 82 now and he's been on the farm all his life ... so he's full of wisdom and stories.
"He's seen farming change over the years really so it's really good to have him as a resource here."
Saunders Senior was also a source of comic relief, he said.
"He's very funny as well - he comes out with the most hilarious lines around - he's a really good character."
Regenerative agriculture featured in "Under a Big Sky," and, while Saunders wasn't against the practice, he said research into how it could mitigate climate change was in its infancy.
"In this book, I talk a little bit about how perhaps it's not a magic bullet against climate change that we're all being told that it is.
"The research is now just starting on how regenerative farming is going to affect the climate."
Saunders' said "Under a Big Sky" touched on the origins of the practice.
"I talk a little bit in this book about the history of regenerative farming and how it came out of the Dust Bowl of America.
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"It was originally to regenerate the topsoil that they had completely obliterated in their own country."
Kiwi farmers were "a long, long way down the track" with adopting new methods of farming, including regenerative agriculture, he said.
"We take on new technology methods, it's something we're very good at here."
The book also explores how Tim and his wife Kathrin try to work with the land rather than against it.
Kathrin is originally from Germany but took to farming life in New Zealand, Saunders said.
"She loves animals and she does a lot of animal medicine and ... herbal medicine.
"She's also tries to ... craft with wool - she's trying to put the value back in wool - she's really, really loving it here."
Saunders wasn't always a farmer and didn't know what he wanted to do when he left school.
He spent time driving a tour bus around New Zealand, (where he first met Kathrin) and tried his hand at a few other jobs before he went out and "experienced the world".
He lived in Germany for two years with Kathrin but started to feel a pull back to New Zealand farming life.
The couple had a discussion about it and decided to make the move, he said.
"It was while I was overseas that I really got a calling back to the land here and back to the wide open spaces."
"Under a Big Sky: Facing the Elements on a New Zealand farm," is out in bookstores now.