Stuart Pettygrove and a friend stared down at their vegetable garden. It was under water.

It was 1968 in Vietnam's rain-soaked central highlands, and the pair, despite having done no research on the region's climate or soil, had banked on the garden as a way of making money to buy a motorbike.

In that moment of failure, Pettygrove found a purpose.

Pettygrove, who went to Vietnam to work on community projects as part of International Voluntary Services, did not decide then he wanted to be a soil scientist. But the seed was planted. He decided that he liked teaching others about agriculture. He just needed some knowledge himself.

"That was a turning point for me," Pettygrove said. "I thought, 'Stu, you have to turn on your brain and start thinking about your life.'"

Today, Pettygrove makes his living as a Cooperative Extension soils specialist conducting research and advising farmers on how to best maintain production without harming the environment.

Unlike many students today, Pettygrove said, he hadn't emerged from his years at UC Berkeley with any real career plans. He joined the grassroots volunteer group with the idea that the work would be the alternative service he needed to fulfill as a conscientious objector to the Vietnam War. The draft board rejected his plan, but Pettygrove volunteered anyway.

When his two-year stint was up, he appeared before the draft board and received a deferment. He then enrolled in a master's program in international agriculture development at Cal Poly, San Luis Obispo. And as soon as he took a soils class, he was hooked, Pettygrove said.

"The idea of decomposition fascinated me," he said. "Soil is where everything goes. Each teaspoon of soil is this incredibly complex environment of water, air and other gases, minerals and living organisms."

He received his Ph.D. in soil fertility at Oregon State University. Pettygrove and his family came to Davis in 1979 from Iowa State University, where he completed postdoctoral work in soil fertility. He's been an extension soils specialist ever since, performing a variety of duties off and on campus.

Pettygrove and his colleagues are in the third and final year of a project teaching farmers from Tulare to Lodi how to better manage their dairy waste. Many dairies unknowingly put too much manure on their fields, creating a nutrient imbalance and contaminating the groundwater below with heavy levels of nitrate, he said.

Pettygrove also guest lectures on campus and teaches UC Master Gardeners programs.

Over the years, too, Pettygrove has honed his religious beliefs. Raised a Methodist in Modesto, he was part of a church group that actively debated pacifism, an experience which helped him decide he wanted to be a conscientious objector.

While at Oregon State, he visited a business meeting of the local Quaker Meeting (congregation). He immediately felt at home with the religious group, which holds pacifism as a major tenet.

"There was something about the calm way they dealt with their business," he said. "They didn't vote, but after a few seconds of silence, someone would speak and everything would become clear."

Pettygrove and his wife are now active members of the Davis Friends Meeting, where he is serving a two-year term as clerk, the closest thing that the egalitarian-minded denomination has to an administrator or spiritual leader.

Pettygrove lives in Davis with his wife, Willa, a self-employed community and transportation planning consultant, and their daughters, Margaret 16; and Grace,13.

Where's your favorite place to work?

Anywhere in the Central Valley. It feels like home to me. I've worked in better climates, like the Willamette Valley in Oregon, but I like the hot summers here. I like the dry grass in the foothills, and I like the oak trees.

What do you enjoy most about your job?

• perfect day at work for me is collecting soil samples at a project site in the cool of the morning, speaking before a group of crop advisors later in the day, then making a farm call with one of our talented UC farm advisors to help solve a problem or plan a project.

And the least?

Driving on Highway 99. If I never had to do it again in my life I'd be very happy.

Who has inspired you the most?

Martin Luther King, Jr. and Robert Cary. Bob was a statewide youth counselor for the Methodist church when I was a teenager. He's a very soft-spoken, kind man with expertise in small-group interactions and organization. When I'm encountering difficulties in human interactions, I hear his voice and some of the things he used to say to people.

• met Martin Luther King, Jr. once when I was 18 years old and I was sent to a conference in Chicago by my church. I shook his hand and sat 50 feet away from where he was speaking. I have read most of his writings.

What are you reading now?

I'm reading a book about Jacob Boehme, born in Germany in 1575. Boehme is thought to have influenced George Fox, the founder of Quakerism.

The book is Insights into the Challenge of Evil by Anne Liem. It's about two very old questions: 'How do we explain the existence of evil and evil people?' 'How do we act in the face of evil?'

What's always in your refrigerator?

There are always one or two bottles of Sudwerk pilsner. That's my stash.•