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Paleoenvironmental Reconstruction Of Quaternary Saltville, Virginia, Using Ostracode Autecology, Austin Gause
Paleoenvironmental Reconstruction Of Quaternary Saltville, Virginia, Using Ostracode Autecology, Austin Gause
Electronic Theses and Dissertations
The Saltville valley in southwestern Virginia is home to Quaternary localities containing paleontological and archaeological remains. Historically the valley has been mined for salt and the small lakes, ponds and springs along the valley floor have a brackish signature. A preliminary report on the site’s ostracode fauna suggested that the site’s water was not always saline. This study analyzed modern and Quaternary ostracodes to understand the valley’s hydrologic and chemical evolution. Sediments contained primarily freshwater species, including the environmentally sensitive Candona crogmaniana. The presence of Pelocypris tuberculatum and a new Fabaeformiscandona species throughout a vertical section spanning the latest Pleistocene …
Response Of Soil Properties To 23-25 Years Of Diverse Crop Rotations And Tillage Systems In South Dakota, Usa, Abdullah H. Alhameid
Response Of Soil Properties To 23-25 Years Of Diverse Crop Rotations And Tillage Systems In South Dakota, Usa, Abdullah H. Alhameid
Electronic Theses and Dissertations
Diverse cropping systems and no-till (NT) are beneficial in improving soil organic carbon (SOC) and other soils properties. The present study was conducted to evaluate the interactions and impacts of long-term tillage and diverse crop rotation systems on soil quality indicators that include a range of soil chemical, physical, hydrological, and microbial properties. The study was established in 1991 at Beresford, South Dakota and included three crop rotation systems [2-yr; maize (Zea mays L.)-soybean (Glycine max L.), 3-yr; maize-soybean-oat (Avena sativa L.), and 4-yr; maize-soybean-oat-wheat (Triticum aestivum L.)] managed under two tillage systems (NT and CT; conventional- tillage). Soil sampling …