Defining cornfield edge effect due to field microclimates

Plain Language Summary As profit margins become increasingly smaller for Midwest farmers, it is crucial to understand how a crop reacts to weather‐related stress. Cornfield edge effect is a new phenomenon Iowa farmers are experiencing where grain yield is lower at the field edge and progressively improves towards the field interior. Our objective was to verify if cornfield edge effect is occurring in Iowa along southern or western field edges when soybean is the adjacent field. And, if an edge effect is observed, determining the timing of the effect through the analysis of grain yield components. Field data collection was conducted in two regions of Iowa in 2019 and 2020 with observations at four distances from the field edge to interior. A field edge effect was detected in three of seven locations. We believe cornfield edge effect is occurring and that often it is a result of lower kernel numbers per ear and/or kernel weight. Plain Language Summary As profit margins become increasingly smaller for Midwest farmers, it is crucial to understand how a crop reacts to weather‐related stress. Cornfield edge effect is a new phenomenon Iowa farmers are experiencing where grain yield is lower at the field edge and progressively improves towards the field interior. Our objective was to verify if cornfield edge effect is occurring in Iowa along southern or western field edges when soybean is the adjacent field. And, if an edge effect is observed, determining the timing of the effect through the analysis of grain yield components. Field data collection was conducted in two regions of Iowa in 2019 and 2020 with observations at four distances from the field edge to interior. A field edge effect was detected in three of seven locations. We believe cornfield edge effect is occurring and that often it is a result of lower kernel numbers per ear and/or kernel weight.