Armstrong Research and Demonstration Farm
In 1995, a liming study was initiated at the Armstrong Farm where acid topsoil had developed from extensive nitrogen (N) fertilizer use in continuous corn (CC) production without liming. In 2003, the experimental area was divided into thirds; a corn-soybean (CSb) rotation occupied two-thirds of the area and CC occupied the remaining third. Hoop building cattle manure was incorporated into the experiment beginning in 2006 to evaluate soil acidity effects on nutrient utilization by crops in both crop rotations and also on soil test values. Manure was applied again in the fall of 2006 to where corn and soybeans would be grown in 2007 to evaluate its effects on both crops as well as soil test values.
Iowa State University
Henning, Stanley, "Corn, Soybeans, and Soil Test Response to Lime and Hoop Building Manure" (2008). Iowa State Research Farm Progress Reports. 639.