How Deep Do Corn Roots Go?
Back in the heat of the 2012 drought, my barber asked me about its impact on the corn crop.
“Well, it’s going to be tough on it,” I replied. “But corn roots have some pretty deep roots. If there’s any trace of water within reach, they’ll find it.
“I’ve heard that,” she replied. “Don’t the roots go as deep as the corn is tall?”
Good question. For the remainder of the year, I asked various agronomist and plant breeders the very same question and received a cornucopia of replies. I even dug up roots on my home farm in northeastern South Dakota and just found about a 2-foot rooting depth. I don’t think that was indicative, though, of many fields that year. Several years of flooding had created a groundwater table so high that the field was virtually subirrigated through the entire drought.
So How Deep is Deep?
Months afterward, though, the question still stuck like a barb in my mind. So I asked Ben Kahler, U.S. seeds general manager for Dow AgroSciences whether corn roots could go 3 feet, 4 feet, 6 feet or deeper.
The answer? All of the above, it turns out.
“Last year, we had very wet conditions that didn’t stress the plant for moisture,” he says. “Roots didn’t have to penetrate the soils very far for moisture, so there was shallower rooting.”
During the drought year of 2012, it was a different story, though. “Roots had to keep going and going to find moisture,” he says.
Here are some more factors that Kahler says affect corn rooting depth.