One of the hottest topics discussed at the No-Till Oklahoma Conference this week was cover crops, as growers look for ways to help fields survive scorching droughts and volatile weather that are seemingly becoming the norm here.
As no-tillers explore their options for covers, an important question that is routinely asked is how cover crops impact water availability for the following cash crop. The Internet makes it easy to scan headlines for research results about this topic — but making a decision on that alone may not be wise.
Just recently, the University of Nebraska posted the results of research of cover-crop water use by the university’s High Plains Ag Lab and USDA-ARS in Akron, Colo.
The article states cover crops caused a reduction in available soil water at wheat planting that reduced yields by nearly 6 bushels per acre for every inch of water used by the cover crop that wasn’t replenished prior to wheat planting.
But earlier this year, Texas A&M AgriLife Extension shared the results of its own research in the Rolling Hills region of Texas, where they examined warm-season cover crops in dual-use wheat systems — for cattle grazing and grain production — and cool-season cover crops in cotton cropping systems.
Texas A&M found that, yes, cover crops do use water, but that didn’t necessarily translate to a reduction in cash-crop performance. Agri- Life Extension researcher Paul DeLaune was on hand this week at the Oklahoma conference to discuss this further.
As a farmer, which study are you to believe? Seeking some perspective, I asked USDA-NRCS soil agronomist Ray Archuleta, who has become the face of the NRCS soil-health movement, what he thought. Archuleta was a keynote speaker at this week’s conference in Norman, Okla.
“Don’t trust anybody’s data. Remember what Ronald Reagan said — ‘Trust, but verify.’ Get the info and go verify it on your own farm,” Archuleta says, suggesting no-tillers give cover crops 3 to 5 years to heal soils before evaluating the results.
“Do cover crops use water? Yes, they do,” he continues. “But what are we trying to accomplish? If you’re focused on 1 year and not seeing 2 to 3 years ahead, you will miss the mark and give up.”