Ted E. Bilderback

Nutrient Sequestration by Vegetation in Bioretention Cells Receiving High Nutrient Loads

AbstractBioretention plant selection for nutrient removal (and even basic plant survival) is an understudied and not-well-understood component of this stormwater control measure. Twelve bioretention cells were constructed to evaluate 16 plants growing in three different media for their ability to remove nutrient pollution from urban stormwater runoff with high nutrient loads. Plants evaluated were pairs of natives and cultivars and included trees (Magnolia and Betula), shrubs (Viburnum and Itea), herbaceous perennial flowers (Helianthus and Eupatorium), a rush (Juncus), and an ornamental grass (Panicum). Eleven of the 16 species (B. nigra; B. Dura-Heat; M. virginiana; M. Sweet Thing; I. virginica; I. Henry’s Garnet; J. effusus; P. Shenandoah; H. angustifolius; H. First Light; and E. Gateway) performed well (grew and were aesthetically acceptable) in the bioretention cells and can be recommended as bioretention plants. Species and cultivar impacted the levels of remediation of the high N and P loads applie...

Nutrient Contribution and Release Kinetics of Vermicompost Amended Pine Bark

The composting of organic waste materials using earthworms yields the value-added product vermicompost (VC). The use of VC as a growing substrate amendment for containerized horticultural crop production is a sustainable nutrient management approach which can benefit crop production by providing plant nutrients and improving crop growth. In order to provide nutrient management guidelines for users of VC amended container substrates, a study was conducted to quantify nutrients supplied to substrates solution and to develop nutrient release kinetic models to predict plant available nutrient based on total initial loading rates. Experimental treatments and results were expressed on a volume basis (4-L container) for easy interpretation and application by growers of crops in containers.

Importance of Limestone Specific Surface for Assessing Neutralization Effectiveness in Soilless Root Substrate

ABSTRACT The relationship of specific surface to particle diameter and calcium carbonate (CaCO3) content of limestone was examined. Limestones obtained from 20 North American quarries were wet sieved into eight particle diameter fractions (600 to ˂38 µm). Specific surface of particles was measured in each fraction following the Brunauer-Emmett-Teller theory. The range in specific surface across the 20 sources varied from 74-fold in the coarsest particles (600–300 µm) to 20-fold in the finest particles (˂38 µm). The pattern of specific surface progressing from the coarsest to the finest particles varied radically between sources. The relationship between specific surface and CaCO3 content was likewise very weak. While particle diameter and CaCO3 equivalent remain the traditional measurements for defining limestone for field production, specific surface provides additional information valuable to define the stricter neutralization capacities of limestone for soilless root substrates.