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 for continuous corn (CC) production without liming. In 2003, the experimental area was divided into thirds; a corn–soybean (CSb) rotation occupies two-thirds of the area for equal areas of corn and soybean test crops and CC continues to occupy the remaining third. Hoop building cattle manure treatments were incorporated into the experiment beginning in 2006 to evaluate soil acidity effects on nutrient utilization by crops in both rotations and also on soil test values. In preparation for the 2008 crop year, manure was applied in the fall of 2007 where corn and soybeans would be grown in 2008.
Iowa State University
Henning, Stanley, "Corn, Soybeans, and Soil Test Response to Lime and Hoop Building Manure in 2008" (2009). Iowa State Research Farm Progress Reports. 457.