By Laura Barrera posted on July 5, 2016 | Posted in Seeding & Planting, Soil Health
Dean Baas believes that we may see crop yields plateau soon if there isn’t more of a focus on soil health.

Despite genetic improvements to corn hybrids and soybean varieties, without soil health — especially soil organic matter — genetics may soon surpass the soil’s capacity to support the improvements, he said during a recent Partnership for Ag Resource Management webinar.

“I would like to propose that the genetic and chemical improvements that we’ve seen through the years have actually masked the decline in soil health,” says the Michigan State University senior extension specialist. “We continue to see yields improve each year. But we’ve looked at the soil organic matter on a lot of ag production land, and it is declining.”
He notes most farmers aren’t producing the contest-winning yields of benchmark growers like no-tiller David Hula, who holds the corn yield world record of 532 bushels per acre.

“You know the capability of some of these corn hybrids,” Baas says. “And you can’t get anywhere close to that on your farm. That’s probably due to the health of the soils you have.”

In the No-Till Farmer article, “The Secrets of No-Till Yield Champions,” Hula mentions that improved organic matter has been key to his success, and in his 28 years of continuous no-till has raised organic matter by 0.5% on his fine sandy loam soils.

“People have a tendency to think that we have some special dirt,” Hula says. “We’ve picked some high-yielding corn in two different counties, and we’ve done it on four different fields in the past, from the mid-300s to 400s in bushels per acre. Our residue decays much faster now. We’ve got all the microorganisms working in the soil, and we’re feeding them.”

Baas believes the key to higher yields — and remaining competitive in agriculture — is for farmers to start building soil health now, since building up soil organic matter is a slow process.

“About the best you’re going to do is about 0.10-0.15% increase per year,” he says. “So that says it’s going to take 6½-10 years to increase your soil organic matter by 1%.

“If you believe your soil will limit you in the future, even if it’s not limiting you right now, now’s the time to get started if you want to turn around that decline in soil organic matter and start building that back up.”

For more information on improving soil health and soil organic matter, see this article from the Samuel Roberts Noble Foundation, and our new no-till management report, “The Secrets of Soil Biology: How to Make it the Engine for a More Profitable No-Till Operation.”