College of Engineering News • Iowa State University

Axle loads, tires, equipment contribute to soil compaction

Everywhere you look, farm equipment keeps getting bigger and heavier and concerns over soil compaction increase as well.

Combine and grain cart axle loads are some of the heaviest on row crop land, with axle loads for larger grain carts easily exceeding 75,000 pounds, according to Mark Hanna, an extension agricultural engineer with Iowa State University.

In 2013, more than 70 percent of farmers who responded to the Iowa Farm and Rural Life Poll indicated they had concerns about soil compaction resulting from heavy equipment.

“Half of the farmers agreed or strongly agreed that they consider the weight of equipment when making purchasing decisions,” Hanna says.

Although compaction is variable depending on soil conditions and wheel loads, some research suggests yields may be decreased by two to five bushels per acre or more in seasons with wetter soil.

For the original Iowa Farmer Today story, click here.