The intentions of aerated compost tea are to provide nutrients to plants or beneficial microbes to the soil or phyllosphere. Compost tea may also contain organic compounds which alter plant physiology (growth or induced defenses). Compost tea is mainly encountered in organic systems, but there is evidence for improved outcomes when using both organic and conventional nutrient sources. The objective of this study is to understand more about the impacts of aerated compost tea (ACT) on soil microbial activity and nitrogen status and plant responses. ACT was applied weekly or bi-weekly as a drench or as a spray to field-grown tomatoes, carrots, and beets fertilized organically or conventionally at two locations in Minnesota. Results presented here focus on produce yield from year 1 of the 3-year study. We found no difference in any of the yield parameters measured due to compost tea application. We generally observed higher yields in organically-fertilized produce in both locations. One location, with a longer history of organic production, had higher soil microbial activity in the organically-fertilized treatment but the difference in yield between conventional and organic tomatoes was similar at both locations.
