Global Maize Project in the United States: Ames, Iowa

The Ames, Iowa research site is one of several around the world involved in the Global Maize Project. There are several focus areas of the project, including the effect of withholding N application on crop productivity and attempting to increase crop productivity while lessening environmental effects. For the project to date, there are several overall system observations and differences. One main result is the considerably lower corn yield when no N is applied, in both systems.

The objective of this study is to determine whether or not an ecological intensification (EI) approach can increase yields more quickly over time than current farmer practice. The study design is a split plot. The main plot is management system: 1) farmer practice (FP), and 2) EI. The split plot is: 1) N application according to the management system, and 2) no N. The treatments are in a randomized complete block, with four replications. Data from 2012 have yet to be analyzed.

The objective of this study is to determine whether or not an ecological intensification approach can increase yields more quickly over time than current farmer practice. The study design is a split plot. The main plot is management system: 1) farmer practice (FP), and 2) ecological intensification (EI). The split plot is: 1) N application according to the management system, and 2) no N. The treatments are in a randomized complete block, with four replications.

The project site was set up in the 2010 crop year. Treatments were not initiated; instead the site was prepared for 2011. This included plot designation and layout, uniform tillage across each crop area, crop planting to begin the corn-soybean rotation, and uniform N application across the corn area. Each plot was harvested for grain yield to investigate any potential underlying effect that might indicate a treatment response when none existed.

Iowa has the largest area planted to maize of all corn producing states in the U. S. and it also has yields that are among the highest in the country. Iowa is within the Mississippi River Basin, which is an area of intense environmental scrutiny due to issues related to hypoxia in the Gulf of Mexico. Examining the gap between average and potential yields provides important information about future production growth in this state as well as other areas in the U. S. Midwest.