Linking land use patterns and pest outbreaks in Bt maize

Data was collected between 2015 and 2018. In this study, we used geospatial tools to examine land use patterns surrounding fields that had previously experienced greater-than-expected injury to Cry3 (Cry3Bb1 or mCry3A) corn roots (>1 node) between the years of 2009 and 2013 in Iowa, USA. Using information obtained from the National Agriculture Statistics Service (NASS) CropScape DataLayer and ArcGIS, we examined patterns of continuous maize cultivation at a distance of 1.6, 3.2, and 16.1 km from problem field centroids. We compared this information to points that were randomly placed on agricultural land in the state of Iowa. In addition, we calculated the proportion of the state that had been planted to third-year continuous maize for the years 2003 through 2018, and performed a correlation with the price of maize in the previous year to determine if maize price influenced continuous maize cultivation. Files are organized by analysis of interest, and each data file is paired with a text file of accompanying SAS code, which was used for analysis. Analyses are: comparison of problem field history of continuous maize cultivation to controls, analysis of variance examining continuous maize cultivation at 1.6, 3.2, and 16.1 km in problem fields and controls, and the correlation of statewide third-year maize with maize price.