(a) Soil in central Iowa with dark, organic-matter-rich topsoil. Iowa's average topsoil depth decreased from 35-45 cm to 15-20 cm during the 20th century due to farming. (b) Severe gully erosion ...

But this may be a first: The Crawford County, Iowa, Soil and Water Conservation District is helping farmers purchase dirt scrapers to prevent or repair soil erosion. Seven farmers responded to the ...

As of late January, soil temperatures show a frost depth of around 17" in Eastern Iowa, and 4-inch soil temperatures well below freezing. Whether this has a negative impact depends on future ...

When European-American settlers first began ploughing in Iowa, they found the weather and local geology had combined this organic mulch with sand and silt to form a nutrient-rich type of soil ...