4d.Progress report.
This report serves to document research conducted under a specific cooperative agreement between ARS and Penn State University. Additional details of research can be found in the report for the parent project 1265-22000-163-00D. Twenty-five years of weed biomass data from the long-term Rodale Institute Farming Systems Trial (FST) was used to assess long-term relationships between weed and crop performance in organic and conventional corn and soybean production. The organic systems were shown to have a greater biological carrying capacity than the conventional system in that higher weed biomass in the organic systems had minimal impact on crop yield compared to the conventional system. Research utilizing subplots with manipulated weed populations within the FST have been established to refine our understanding of weed-crop competition in this trial.