Farmers on the Northern Plains have heard a lot about soil health recently. They'll be hearing a lot more in the years ahead, speakers at a soil health conference say.
"We have to understand more about how soil works" to maintain its sustainability, says Hal Weiser, soil conservation specialist with the U.S. Department of Agriculture's Natural Resources Soil Conservation Service in Jamestown, N.D.
Reaching that goal won't come quickly or easily, but "eventually we'll get there," he says.
Weiser spoke Feb. 28 in Grand Forks, N.D., at the Grand Forks County Soil Health Workshop. About 130 people attended the workshop, the first of its kind, which organizers hope will become an annual event.
Sponsors were the Grand Forks County Soil Conservation District, the Natural Resources Conservation Service, the North Dakota State University Extension Service and the North Dakota Department of Health.
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Soil health is soil's capacity to "function within ecosystem and land use boundaries, to sustain biological productivity, and promote plant, animal and human health," according to information from Abbey Wick, an assistant professor of soil science and extension specialist at NDSU who spoke at the event.
Soil health is based on a combination of physical, chemical and biological properties. Physical properties include compaction and surface sealing, while chemical properties include nutrient availability and nutrient holding capacity, she says.
Soil's biological properties, which include root, microorganisms and organic matter, need more investigation, Wick says.
Among the ways to build organic matter in the soil and improve soil health in general:
•Reduce tillage. Doing so provides more habitat for helpful soil microbes, among other benefits.
•Diversify crop rotations. Planting crops with different root structures and that require different inputs can lead to more microbial diversity.
•Add organic matter. Compost, manure and crop residue help soil health in a number of ways.
Focus on soil salinity
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Weiser talked about managing evapo-transpiration to control soil salinity. Evaporation is the loss of water from soil. Transpiration is the loss of water from plants. Evapo-transpiration is a combination of the two.
"Salinity has become more of an issue in the past few years," he says, in part because rising water tables have brought more salt to the surface.
Too much salt in the soil hurts plant roots' ability to take in water and other nutrients.
The growing number of acres planted to corn and soybeans, which are particularly sensitive to salt, also has increased attention on soil salinity in the Upper Midwest.
An estimated 2 million acres on the Northern Plains, including Canada, are moderately saline, while 275,000 acres in the Red River Valley of eastern North Dakota and western Minnesota have moderate or greater salinity, according to estimates.
"It's all about managing the water cycle," Weiser says of efforts to control soil salinity.
Raising cover crops and crops that require large amounts of water are among the ways of doing that.
Planting crops such as barley, durum and sunflowers that tolerate salt relatively well is another way of dealing with soil salinity.
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Most of the region is locked in drought. If dryness persists, the soil salinity situation will improve, but remain a concern, Weiser says.
