Cover Crop Mixture Diversity and its Effects on Biomass Production, Weed Suppression, Soil Fertility, Soil Microbial Biomass and Community Structure, and Performance Stability

Cover Crop Mixture Diversity and its Effects on Biomass Production, Weed Suppression, Soil Fertility, Soil Microbial Biomass and Community Structure, and Performance Stability

Summary

Twenty cover crop treatments representing both cover crop monocultures and mixtures were compared in terms of their biomass production, weed suppression, nutrient scavenging, and shallow soil moisture.

Notable observations from from the first year of data collection and analysis:

• • Average biomass production was positively related to increases in cover crop mixture functional diversity but not to increases in species diversity in the absence of increases in functional diversity. 

• • Weed suppression and nutrient scavenging was strongly driven by biomass production.

• • After the cover crops winter-killed, shallow soil moisture was also positively related to cover crop biomass production—likely due to a mulching effect of the dead cover crops.

Objectives/Performance Targets

The objective of this study was to evaluate the effect of cover crop mixture diversity on a variety of parameters and then share the results with both farmers and researchers.

The first season of this study has yielded a popular press article, a presentation at a farmer conference, and a presentation at a research conference.

Accomplishments/Milestones

The first season of data collection and analysis has been completed with the exception of the soil microbial community analysis, which is ongoing.

The second season of data collection and analysis is underway.

Once all the data has been gathered and analyzed, the results will be shared through extension publications, scientific publications, and additional conferences.

Impacts and Contributions/Outcomes

Preliminary research results have been shared with farmers and researchers at the 2014 MOSES Organic Farming Conference (February 27 – March 1) and the 2014 Soil Water Conservation Society International Annual Conference (July 27 – 30), and through the Organic Broadcaster (July/August 2014 issue).

We hope that these forms of outreach and education has helped to increase awareness and knowledge about cover crop mixtures amongst both farmers and researchers as well as helped to inform decision-making regarding the use of cover crop mixtures.

Collaborators: