Microorganism Diversity from Dredged Sediments

The application of sediments dredged from waterways to agricultural fields has increasing promise but herbaceous plant species may have difficulty establishing on dredged material because of low nutrient availability, inhibitory levels of toxins, unsuitable moisture conditions, and lack of microorganisms capable of ameliorating these characteristics. To counteract these issues, we sought to understand if the use of a cover crop would increase the abundance, diversity, and function of beneficial soil microorganisms compared to harmful microorganisms in dredged sediments. To do so, we collected soil samples from two 100% dredged sediment plots, one where winter cereal rye (Secale cereal) was grown as a winter cover crop and one left fallow over the winter, followed by traditional corn (Zea mays) planting. We sampled both plots three times during the growing season: prior to cover crop application, following cover crop application but prior to corn planting, and following final corn harvest. We then used high throughput sequencing to identify the bacterial and fungal microorganisms present in the samples.