Less Concern about Compaction in Northern Plains
Friday, April 15, 2005
filed under: Optimizing Plant Development/Yields
Albert Sims, soil scientist at the University of Minnesota’s Northwest Research and Outreach Center in Crookston, recalls the first time he saw sugar beet harvesting in the Red River Valley.
“I was horrified,” he said, of his first glimpse of the late fall beet hauling campaign, that involves heavy equipment traveling up and down fields in sometimes muddy conditions. “Where I grew up (Nebraska) we might not be able to farm that land again. I’ve seen compaction effects linger 10 years after it happened. But up here, it doesn’t seem to be an issue.”
Certainly, conditions such as soil dryness and field traffic can result in surface compaction, but nothing like the “hard pan” subsoil conditions that can be found in the High Plains. “In my 10 years here, I’ve never dug down and hit a subsoil compaction layer,” says Dave Franzen, extension soils specialist at North Dakota State University, Fargo.
Why is soil compaction more of a problem in the Southern Plains compared to the Northern Plains? It doesn’t seem to be cycles in temperature: the U of M points out that although northern soils are subject to annual freeze-thaw cycles, freezing to depths of 3 feet or more, only the top 2 to 5 inches will experience more than one freeze-thaw cycle per year.
Both Sims and Franzen agree that it’s likely the shrink/swell capabilities of northern soils, combined with higher organic matter (and thus better soil elasticity) that helps keep soil compaction from becoming a yield-limiting factor in the Northern Plains.
Sims says he hears some producer talk about using subsoilers from time to time, but that it is generally a little-used practice in the Northern Plains, with little data to suggest a yield benefit by subsoiling. In a study near Waseca, Minn., for example, subsoiling to a depth of 16 inches failed to increase yields on the 20-ton per axle treatments for either corn or soybeans, and actually decreased corn yield 11 bu/a in one of the two years. “Here (in the northern Red River Valley) subsoiling might be more like running a knife through butter,” says Sims, “because as soon as that soil wets back up, it swells again.”
That’s not to say soil compaction should ever be discounted in the Northern Plains. Both Franzen and Sims say it could become a production issue, particularly with excessive field traffic too early in the spring. Northern growers who suspect soil compaction might be an issue should try one of the methods suggested by Sonnenberg, or consult with an agronomist – Tracy Sayler
Consider Sunflower on Saline Soil
Sunflower is one of the better crop choices to consider on saline soils, which can be a particular problem in some High Plains irrigation areas. “Sunflowers will accept that kind of condition nicely. It’s more tolerant than corn, and just below barley,” says Ron Meyer, area extension agent, Colorado State University, Burlington. He says that there areis some sunflower grown on salty ground in the Arkansas River Valley, south and east of Denver.
As well, North Dakota State University points out in the bulletin “Managing Saline Soils in North Dakota” (http://www.ext.nodak.edu/extpubs/plantsci/soilfert/sf1087.pdf) that a late-maturing, deep-rooted crop with salt tolerance would be a good choice to help lower the water table.
Some sunflower hybrids perform better on salty ground than others; consult with a seed company representative about what might work for you.