Spatial Corn Yield Variability in the Loess Hills of Western Iowa: A Critical Look.

Spatial Corn Yield Variability in the Loess Hills of Western Iowa: A Critical Look

Abstract:

Modern row crop production in Iowa has become increasingly tied to precision agriculture and the creation of large volumes of data.  Using Geographic Information Systems technology, these data are utilized to make crop yield variability maps, fertility maps and plant seeding maps. The objectives of this study were to: (1) identify significant long term corn yield variability in the Loess Hills of western Iowa, and (2) interpret any relationships between identified yield variability clusters and their associated soil and field characteristics.

            For the first objective, a 32 hectare site, consisting predominantly of Galva Silty Clay Loam and Judson Silty Clay Loam, was located in Sioux County, Iowa. Multiple years of geo-referenced corn (Zea mays) yield data were collected from 2006 – 2013 and imported into ArcGIS.  A cluster analysis tool was used to identify persistently high and low, yielding clusters which accounted for 3.2% of the study site during the study period. Average corn yield for  the site was 11,017.39 kg ha^-1 and the mean yields for the low and high cluster areas  were  7,9889 and 14,339.63 kg ha^-1, respectively.   For objective 2, appropriate models will be used to examine the effects of spatially related soil physical and chemical properties, topography and other temporal properties on corn yield variability patterns in the field.