Barnes Soil Series

Barnes soil is a Mollisol — a soil order defined by a thick, dark surface layer called a mollic epipedon. That black layer, often 12 to 15 inches deep, is packed with organic matter from thousands of years of prairie grasses growing, dying, and decomposing into the ground.

Barnes soil formed in glacial till — the rocky, unsorted debris left behind when the Laurentide Ice Sheet retreated roughly 10,000 years ago. The flat to gently rolling topography that ice sheet left behind, combined with a humid continental climate, created ideal conditions for deep prairie soils to develop.

Soil scientists at the USDA Natural Resources Conservation Service selected the Barnes series to represent North Dakota because it is the most widespread and economically important soil in the state. It covers more land in North Dakota than any other named soil series.

The series is named after Barnes County in southeastern North Dakota, where it was first formally described. Barnes County sits in the heart of the glaciated plains — the landscape that defines the state's character more than any other.

Barnes soil is recognized by the USDA as North Dakota's state soil. It was selected to represent the sweeping glaciated prairies that stretch across central and eastern North Dakota and define the state's role as a world leader in wheat and sunflower production.

Dig into Barnes soil and the first thing you notice is the color: nearly black at the surface, the darkest topsoil you will find in North America. A foot or more of this organic-rich material sits above a brown subsoil, which gives way to the pale, calcium-streaked glacial till that underlies the entire region. Each layer holds a record of 10,000 years of prairie history.

Barnes soil covers the glaciated plains of central and eastern North Dakota — the nearly flat to gently rolling landscape left by the retreating Laurentide Ice Sheet. It sits on upland summits and side slopes at elevations of 1,200 to 2,000 feet, in areas that receive 15 to 22 inches of precipitation per year.

The series is most concentrated in the counties around the Red River Valley and the Coteau des Prairies. Barnes County is the type location, but the soil is equally common in Stutsman, Cass, Ransom, LaMoure, and a dozen other central and eastern counties.

Barnes soil is the engine of North Dakota's farm economy. Spring wheat and durum wheat are the primary crops — North Dakota grows more durum than any other state, and Barnes soil is where most of it grows. Sunflowers, canola, flaxseed, and barley are also major crops on this soil.

Soybeans and corn have expanded onto Barnes soil in recent decades as varieties adapted to short growing seasons reached the market. The thick organic layer stores nutrients and moisture, reducing the fertilizer and irrigation inputs that thinner soils require.

Before farming, Barnes soil supported northern mixed-grass prairie — big bluestem, little bluestem, green needlegrass, and western wheatgrass. Small patches of native prairie remain in areas too wet or rocky to plow, and these remnants support nesting habitat for sharp-tailed grouse and waterfowl.