Identifier

etd-11162012-115417

Degree

Master of Science (MS)

Department

Plant, Environmental Management and Soil Sciences

Document Type

Thesis

Abstract

High salinity concentrations in soils used to renovation and construct levees adversely affect levee’s performance due to increased susceptibility for erosion problems. Dispersion of the soil particles caused by salts and seal formation affect levee structure stabilization and vegetation establishment is impaired due to lower water infiltration capacity in levees; and high osmotic pressure exerted by salts reducing water availability for seed germination leaving levee surface prone to severe rilling and soil loss from runoff erosion. The objectives of this research were determine if expanded shales, clays, and slates-light weight aggregate (ESCS-LWA) over clay reduces erosion and evaluate how ESCS-LWA affects vegetation establishment from seed. Alternatives to soft armoring erosion protection such as concrete t-walls, concrete covering or rock applications are expensive and could limit levee expansion. The use of mulches such as ESCS-LWA can significantly reduce soil erosion and pollutant transfer as a transition to vegetation establishment. Aggregate particle reduce evaporation at the soil surface during wet periods by disrupting the soil-atmosphere continuum. The ability of ESCS-LWA to reduce erosion and increase water availability should allow for increased seed germination and plant growth. To test this hypothesis, four ESCS-LWA treatments (0, 50, 100, 150% ground coverage) were applied to bare soil and seeded with 75 kg PLS bermudagrass ha-1. Treatments were subjected to a rainfall simulation at 75 mm hr-1 at 30% slope for a 30-min runoff period in a greenhouse. Prior to simulation soil moisture was recorded with runoff volume and total solids (TS) collected during simulation. The ESCS-LWA increased the time until the onset of runoff and reduced TS losses >90% compared to bare soil. Increasing ESCS-LWA coverage resulted in higher soil moisture for 30 days post-rainfall simulation with 50% and 100% ground cover resulting in the highest bermudagrass coverage and biomass.

Date

2012

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Beasley, Jeffrey S.

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