From the field to the classroom to the garden, Richard Rust devoted his life to the soil.

Rust, a former professor of soil science at the University of Minnesota, surveyed the state's land and developed a groundbreaking way of growing food from it. He died Aug. 19 at the age of 94.

Born in 1921 in rural Bunker Hill, Ill., and educated in a one-room schoolhouse, Rust was one of 10 children — and the first in his family to give up the farming life to become an academic. But he never left agriculture far behind.

After serving as an Army Air Corps pilot in England during World War II, Rust earned a doctorate from the University of Illinois, and joined the Department of Soil, Water and Climate at the University of Minnesota in 1956.

At the U, he served as the liaison between the state of Minnesota and the federal government on a widespread survey of the nation's soil, a survey that's still used today as a reference. It analyzed how soils differ across the state, affecting how they are managed for uses such as agriculture and road-building.

That work later led Rust, with student Pierre Robert, to develop the framework for "precision agriculture," a concept that has transformed modern agriculture and conservation, colleagues say.

Fields had long been treated with fertilizer, herbicides and pesticides in a one-size-fits-all manner. But Rust believed that considering the soil's properties in different areas of a single field — how much water it could hold or how dense the weeds were — could help farmers maximize crop yield without over-treating crops with fertilizer and pesticides.

Precision agriculture practices helped farmers, while also reducing the effect of agriculture on water quality — "a win-win situation," said Ed Nater, a longtime colleague and soil science professor at the U.

Rust also assisted in criminal investigations as an expert in forensic soil science. For a high-profile murder and kidnapping in 1980, Rust and a colleague were able to identify the location of a body in a cornfield by analyzing soil and plant debris in the abduction vehicle.

Despite being at the forefront of his profession, Rust stayed humble about his accomplishments.

"He never talked about what he did," said daughter Deanna Rust Zimmer, of Lincoln, Neb. "He made quiet influences, behind the scenes."

He took his work home in a different way, by working the land.

When the family moved to St. Paul in 1955, he started a garden behind the house. But it wasn't enough. Rust later rented out a vast plot on another property that was more like a small farm than a home garden. There, he grew all kinds of crops from seed to fruit, including his beloved sweet corn.

Rust enjoyed baking pies and sharing his fruits and vegetables with family members and members of his church, Emmaus Lutheran in St. Paul.

"He shared with us the bounty of what he knew about the soil," said the Rev. Tom Trapp.

Rust was devoted to the church and its members. Each week, he would drive recordings of the Sunday service to members of the congregation who could not attend.

Rust retired from the U in 1989, but his later years were still marked by hard work as the sole caretaker for his wife, Laura, who died of Parkinson's disease in 2007, and for a disabled son, Dickey. Another son, James, died in 2005. Rust also lost many siblings over the years.

"In many ways, he was the last man standing," said daughter-in-law Joanne Rust. "He was so stoic about it all. He would just look down and nod, and kind of get to work."

He was working the soil in his garden until just three weeks before he died.

Rust is survived by daughter Deanna and sons Robert, Richard and Mark. Services will be held at 2 p.m. Saturday at Emmaus Lutheran Church, 1074 Idaho Av. W., St. Paul.

Sharyn Jackson 612-673-4853