UMD Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/3

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.

More information is available at Theses and Dissertations at University of Maryland Libraries.

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2010 - 20152

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Subject: search.filters.subject.organic material

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    A Comparison of Organic Matter Amendments for Use in Extensive Green Roof Substrates
    (2015) Barton, Elizabeth Taussig; Lea-Cox, John D; Cohan, Steven M; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Organic matter is important for water retention and nutrient availability in green-roof systems. Yet few quantitative green-roof studies provide data for various sources of organic matter (OM). Coconut coir (CC), rice hulls (RH), SmartLeaf® (SL), and mushroom compost (MC) were used as green roof substrate amendments. The effects of OM on water-holding capacity, nutrient availability and plant establishment were measured. Growth of Phedimus kamtschaticus was greater with MC or SL compared to CC or RH. Substrate moisture and nutrient availability were significantly affected by OM source during an 8-month rooftop experiment and a 6-month growth chamber study. Coconut coir showed high moisture retention, low nutrient availability and low aboveground biomass, indicating that nutrient availability is crucial to successful plant growth and establishment on a green roof. Composted materials such as MC and SL that have higher levels of available nutrients, promote better growth than unprocessed materials like RH and CC.
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    Redoximorphic Features Induced by Organic Amendments and Simulated Wetland Hydrology
    (2010) Gray, Adam Lincoln; Rabenhorst, Martin C; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    During wetland construction, it is common to add organic amendments to the soil, although little research has evaluated the effects of organic additions on the development of redoximorphic features. The objective of this study was to evaluate the effects of adding different types of organic materials, using different methods of incorporation, on the formation of redoximorphic features under hydric soil conditions. Five types of organic materials were incorporated into soil cores lacking redoximorphic features, using three incorporation methods. Cores were established as mesocosms in a controlled greenhouse environment or transplanted into a natural wetland. Mesocosms were periodically dissected and examined for newly formed redoximorphic features. The method of incorporating organic materials had a significant influence on the development of redoximorphic features, but the type of organic material had no significant effect. Organic materials should be concentrated into deeper zones during wetland construction to maximize development of redoximorphic features.