MLRA 102B Loess Uplands and Till Plains

Iowa, Minnesota, South Dakota, and Nebraska

43,790 km² (16,910 mi²)

Land Use

Most of this area is in farms, and about 70 percent is cropland. The area is used primarily for crops grown for sale or for feeding livestock. Corn, soybeans, grain sorghum, alfalfa, and oats are the principal crops. Wooded sections generally are narrow bands along streams and rivers or are shelterbelts around farmsteads. Irrigation is increasingly practiced in areas where water supplies are available. Urban development is expanding around some of the larger cities.

Elevation and Topography

Elevation ranges from 1000 to 1300 feet (300 to 400 meters) on the Missouri River bottom land to 1300 to 1600 feet (400 to 500 meters) on uplands. The loess uplands are characterized by long smooth slopes and well-defined drainages. The till plains are mostly nearly level to gently rolling and have many depressions and ill-defined drainages. Steeper slopes are on the sides of drainageways and in breaks adjacent to some of the larger tributaries.

Climate

Average annual precipitation-20 to 26 inches (500 to 650 mm). Half or more of the precipitation falls during the growing season. Precipitation in winter is mainly snow that averages about 25 to 41 inches. Average annual temperatures to 52° F (9 to 11° C). Average freeze-free period-135 to 165 days.

Water

Precipitation is the principal source of moisture for crops, but in some years it is inadequate for maximum production. Shallow wells are the principal source of water for domestic and livestock needs. Water for irrigation is available along some of the major rivers and the larger tributaries.

< Back to MLRA 102B