Cover cropping is the management strategy of growing a winter cover crop in between cash crops to increase ecosystem services and multifunctionality. Farmers need to control weed growth and pest populations, while also trying to increase cash crop yield. Cover cropping has potential to help farmers achieve more sustainable agriculture by decreasing harmful environmental impacts of using pesticides/herbicides and increasing crop yield by improving soil structure, porosity, and nutrient retention.
While cover cropping is being promoted as a management strategy that will provide ecosystem services, we know that not all cover crops provide the same services. Some cover crops increase nitrogen in the soil, while others are better at weed suppression. Mixtures of cover crops could be tailored to achieve ecosystem services desired by individual farmers.
However, it is unclear how cover cropping impacts soil microbial communities and if the microbial communities are then impacting cash crop growth/performance.
While cover cropping is being promoted as a management strategy that will provide ecosystem services, we know that not all cover crops provide the same services. Some cover crops increase nitrogen in the soil, while others are better at weed suppression. Mixtures of cover crops could be tailored to achieve ecosystem services desired by individual farmers.
However, it is unclear how cover cropping impacts soil microbial communities and if the microbial communities are then impacting cash crop growth/performance.
Specific questions that we are addressing include:
1. How does cover cropping impact bulk soil fungal communities?
For this objective, I was interested in studying different aspects of the fungal community. Most studies focus on AM fungi or fungal insect pathogens and have seen differences in AM fungal inoculation potential of cash crops and changes to insect pathogen abundances. Each study has found that cover crop affects on fungal communities appears to be specific to the crop identity. So, what happens when a cover crop mixture is planted? Do all mixtures affect the fungal communities in a deterministic way or will the mixture contain characteristics specific to the species included?
2. Does below ground diversity echo above ground diversity?
It has been hypothesized that increasing above ground diversity will lead to increased below ground diversity. In our case, using a cover crop mixture should increase below ground alpha-diversity when compared to a monoculture cover crop.
3. How does previous management history affect microbial communities?
It is often difficult to discern how previous management histories affect microbial communities in bulk and rhizosphere soils. Many unanswered questions fall into this broader question.
Are there certain groups of organisms that are sensitive to management legacies? How does a legacy of herbicide application compare to a legacy of tillage?
For this objective, I was interested in studying different aspects of the fungal community. Most studies focus on AM fungi or fungal insect pathogens and have seen differences in AM fungal inoculation potential of cash crops and changes to insect pathogen abundances. Each study has found that cover crop affects on fungal communities appears to be specific to the crop identity. So, what happens when a cover crop mixture is planted? Do all mixtures affect the fungal communities in a deterministic way or will the mixture contain characteristics specific to the species included?
2. Does below ground diversity echo above ground diversity?
It has been hypothesized that increasing above ground diversity will lead to increased below ground diversity. In our case, using a cover crop mixture should increase below ground alpha-diversity when compared to a monoculture cover crop.
3. How does previous management history affect microbial communities?
It is often difficult to discern how previous management histories affect microbial communities in bulk and rhizosphere soils. Many unanswered questions fall into this broader question.
Are there certain groups of organisms that are sensitive to management legacies? How does a legacy of herbicide application compare to a legacy of tillage?
