Search for: All records

Abstract Soil degradation is a worldwide problem, causing the declining performance of many plant species. Recently, the application of sediments dredged from aquatic waterways has received attention for their potential as an organic amendment to revive degraded agricultural soils. In Ohio, dredged sediment research has largely focused on the success of corn (Zea mays) or soybean (Glycine max) following the application of dredged sediments from the Toledo Harbor, neglecting the potential for dredged sediments from the other eight harbors and waterways to change plant performance as well as failing to quantify benefits for other commonly grown crops in the region. In a greenhouse experiment, we applied dredged sediments from the Lorain Harbor to degraded agricultural soils across a variety of application ratios and quantified changes in germination, height over the growing season, final biomass, and yield for canola (Brassica napus), tall fescue KY 31 (Festuca arundinacea), and corn to better understand the potential for dredged sediments from this location to increase performance for a variety of regionally important plant species. Overall, plants grown on agricultural soils supplemented with dredged sediments from the Lorain Harbor consistently grew taller, faster, and were larger than the 100% dredged sediment treatments. Furthermore, both corn and tall fescue grown on agricultural soil supplemented with dredged sediments had greater yield compared to their counterparts grown on unamended agricultural soil. In whole, outcomes from this research contribute to a growing body of research that support the use of dredged sediments as a soil amendment for agricultural soils. 

Midwestern forests are currently impacted by two prominent invaders, the emerald ash borer (EAB; Agrilus planipennis) and Amur honeysuckle (AHS; Lonicera maackii). The loss of ash (Fraxinus spp.) trees due to EAB invasion can further facilitate AHS invasion, driving changes in the composition of forest leaf litter to reflect a greater portion of labile, more easily decomposed litter. To evaluate the extent to which these changes alter ecosystem function, we conducted litter bag and culture-based decomposition experiments using leaf litter from sugar maple (Acer saccharum), oak (Quercus spp.), black ash (Fraxinus nigra), green ash (Fraxinus pennsylvanica), spicebush (Lindera benzoin) and AHS. To further understand the mechanism driving differences in decay rates, we inoculated six species of decomposing fungi separately onto both single species and multispecies (half AHS and half native species) leaf litter and measured decomposition rate, fungal growth and enzymatic activity in laboratory-based cultures. AHS leaf litter decomposed faster, had increased fungal growth, and had higher activity for carbon degrading enzymes compared to native species leaf litter. Furthermore, multispecies mixtures followed the same patterns as AHS, suggesting that the addition of AHS to leaf litter to native litter will accelerate ecosystem functions related to carbon breakdown. Consequently, forests that experience the invasion of AHS and EAB induced loss of ash are likely to have faster rates of decomposition, potentially resulting in an influx of available nutrients.