Data for: Weed community composition in simple and more diverse cropping systems

Data are for weed abundance and crop yield in three different rotation systems suitable for the Midwestern USA. Individual weed species abundance (stand density and aboveground mass) data were collected from eight quadrats per experimental unit over a four-year period. Simpson’s diversity, evenness, and richness indices were calculated based on weed stand density and aboveground mass. Crop yields were measured at the experiment site and standardized to Mg/ha. Iowa and Boone County corn, soybean, oat grain, and alfalfa hay yields were downloaded from USDA National Agricultural Statistics Service Information. The dataset presented here contains tabular data in .csv and .xlsx file formats. Change log: Additions and corrections made to the oat_g_1720_clean, IA_yield_clean, and alfalfa_1720_clean .csv files on 08/12/2024.