Although more than two decades of no-till practices have been good to Mark Montel, 8 years ago he describes hitting a wall as his regular soil tests showed he wasn’t building soil organic matter very quickly.

During my 13 years in the Air Force after graduating from Iowa State University in 1956, a lot of things changed. In the military, I was part of a two-man team that flew the experimental SR-71, which became the world’s fastest airplane. It still holds speed records of more than 2,000 miles per hour.