ISSUE 2 May 22, 2008
TILLAGE AND WIND EROSION
On Saturday, May 17, the Red River Valley experienced a mini dust bowl, as winds clocked at 40-mph to near 60-mph whipped up soil from recently seeded fields. Driving speeds were reduced to 25 mph due to visibility problems in some parts of Pembina County, according to Leslie Lubenow, Pembina County Extension agent. About 17,000 acres of sugarbeets need to be replanted as a result and many more acres lost soil that will take decades to replenish.
The first figure shows a ditch filled with soil from surface creep wind erosion in the adjacent field. Many more tons of topsoil were lost into the air. The second figure shows a newly seeded sugarbeet field on the right, and a wheat field on the left. The soil saltation from the sugarbeet field was so bad that the grower was forced to field cultivate the wheat field to slow the soil loss in it.
Fig. 1. Soil from adjacent field fills in a
ditch as a result of the May 17 wind storm.
(Image courtesy of Tyler Grove, American
Crystal Sugar Co. agriculturalist.)
Fig 2. Soil from sugarbeet field (right)
moved into the wheat field (left), causing
saltation and soil loss. The grower field
cultivated the emerged wheat field to stop
the erosion. (Image courtesy of Tyler Grove,
American Crystal Sugar Co. agriculturalist.)
Conservation tillage practices for the Valley have been studied for thirty years at NDSU. Although no-till is not practical, there are some measures that can be taken to reduce the impact of wind. Growers that used a cover crop were better off than those that did not. Cover crops are especially practical now with glyphosate resistant crops.
Research continues into the use of strip-till in sugarbeets and other row-crops. Although there are challenges with using this tillage system in this area, the results so far make us hopeful that this might soon make dust storms in the region much more rare.
Dr. Dave Franzen
NDSU Extension Soil Specialist
HOW DEEP DID YOU PLANT YOUR SMALL GRAINS?
Now that the wheat and barley crop has emerged in most of North Dakota, it is a good time to confirm how deep the crop was actually planted, according to Jay Goos, Professor of Soil Science at NDSU. "A farmer can confirm the effective seeding depth of small grains by measuring the length of the 'white zone'," says Goos. The "white zone" is a term coined by Goos to describe the length between the seed piece, and an imaginary line on the stem, where the stem turns from white to green. "Going to a field, digging up random plants, and measuring the length of the white zone can give a farmer an accurate measure of the effective seeding depth, after the soil has settled around the seed," he says. "There are a lot of patchy and streaky stands of wheat in eastern North Dakota this spring. This technique might prove helpful in the next week or so, to help figure out why some rows emerged more slowly than others. Was the seeding depth too deep or too shallow? Examining the white zone length might be useful in helping farmers figure out why certain rows emerged well, while others didn't."
In most cases, measuring the length of the white zone is simple, as there is not much of a "bend" in the shoot. "If there is a bend in the shoot, as when a shoot curved around a clod to emerge, it is more accurate to measure length of the white zone without unbending the shoot. The vertical distance between the seed piece and where the stem turns green is the important measurement," according to Goos.
This picture shows the length of the white
zone for wheat plants planted 1.2 inches deep.
If pressed to give an "ideal" length of the white zone in wheat, Goos would say that it would be about one inch for a typical year. "Farmers sometimes need to seed more deeply than that, especially in dry years, in order to 'hit moisture,' but deep seeding is not without risk. Tiller production and crown root production generally go down as seeding depth is increased, and if seeding is too deep, the stand will suffer. Seeding too shallow has risk as well, involving the seed being stranded in dry soil, or in a crust. The worst-case scenario with shallow seeding is when seed begins to grow, and then dries out and dies. Seeding too shallow also can lead to some heat stress on the crown if the weather turns very warm early in the season. We observed this in 1988, with many hot days in May and June. So, there is no ideal seeding depth for all conditions. But, it is important that farmers get into their fields and learn to correlate the length of the white zone to what produces good stands and vigorous tillering."
In general, Goos says, farmers don't plant as deeply as they used to. "No-till and one-pass seeding systems generally lead to shallower planting than systems used years ago, when the standard practice was to till the land and then plant a week or so later in much looser and drier soil."
Dr. Jay Goos
NDSU Soil Science Department