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dc.contributor.authorHoskins, Tyler Courtneyen_US
dc.date.accessioned2014-05-29T08:00:27Z
dc.date.available2014-05-29T08:00:27Z
dc.date.issued2014-05-28en_US
dc.identifier.othervt_gsexam:2907en_US
dc.identifier.urihttp://hdl.handle.net/10919/48165
dc.description.abstractIncreased water- and fertilizer-use-efficiency in containerized crop production, via reduced water loss, enhances crop-available nutrients while reducing non-point source agrichemical contributions in accordance with regulatory standards. Previous studies detailed nutrient leaching patterns throughout crop production seasons, leaving little known about water and dissolved nutrient (solute) movement through soilless substrates during irrigation. The following experiments evaluated fundamental water and solute transport principles through pine-bark based substrates. 1) Ilex crenata Thunb. 'Bennett's Compactum' were grown in 2.7 L containers. Tensiometers detected wetting front (WF) movement throughout the substrate during irrigation. 2) Tracer solution (containing NO3-, PO43- and K+) and deionized water (DI) were applied to substrate-filled columns to characterize tracer breakthrough under saturated and unsaturated conditions. 3) Controlled-release fertilizer (CRF) was topdressed (surface-applied), incorporated (throughout substrate), dibbled (center of substrate) or not applied to fallow substrate, irrigated with DI and leachate analyzed to determine nutrient concentrations throughout irrigation. Tensiometers revealed that seasonal root growth affected substrate pre-irrigation moisture distribution. Wetting fronts channeled through the substrate before becoming thoroughly wetted. Tracer breakthrough occurred with less effluent volume under unsaturated conditions. Breakthrough of NO3- and PO43- was relatively conservative, though 37% of K+ was retained by the substrate. Leachate concentrations for topdressed and incorporated CRF peaked early (first 50mL effluent) before diminishing with continued leaching. Leachate concentrations for dibbled CRF initially increased (first 150mL leachate), plateaued and then diminished. These results show the relative rapidity which water and solutes move through pine-bark during irrigation and demonstrate methods for future research on within-irrigation solute transport.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectBreakthrough curveen_US
dc.subjectcation exchange capacityen_US
dc.subjecteffluenten_US
dc.subjectleachateen_US
dc.subjectnutrient use efficiency preferential flowen_US
dc.subjectroot growthen_US
dc.subjectsolute transporten_US
dc.subjectwater application efficiencyen_US
dc.subjectwetting fronten_US
dc.titleWater and nutrient transport dynamics during the irrigation of containerized nursery cropsen_US
dc.typeThesisen_US
dc.contributor.departmentHorticultureen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineHorticultureen_US
dc.contributor.committeechairOwen, James Stetteren_US
dc.contributor.committeememberEaston, Zacharyen_US
dc.contributor.committeememberNiemiera, Alexander X.en_US


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