Crop rotations, tillage, and fungicides are three central tools of crop management. Since ancient times, growers have used crop rotation to reduce disease pressure and achieve the yield benefits typically seen after rotation with a different crop. Over the last few decades, agronomic research has also indicated that reduced tillage or no-tillage improves crop yields in a sustainable manner. Growers also use chemical control measures to manage pathogens – in particular, fungal pathogens that attack their crops. Recent research has shown that fungicides can provide significant benefits to growers in the Midwest. The benefits of these management practices have been studied for decades, but the degree to which soil and plant microbes contribute to these benefits remains unclear. The central research questions that will be addressed in this project are:
1. How do management practices (crop rotation, reduced tillage, and foliar fungicide application) affect the bacterial and fungal communities associated with the soil, roots, and leaves?
2. Can we link the benefits of these management practices to specific types of microbes (reduced abundance of pathogens) or characteristics (richness, diversity, evenness) of the microbial communities?