Soil Carbon and Nitrogen Dynamics Across the Hillslope-Riparian Interface in Adjacent Watersheds with Contrasting Cellulosic Biofuel Systems

Files
TR Number
Date
2014-05-27
Journal Title
Journal ISSN
Volume Title
Publisher
Virginia Tech
Abstract

Climate change resulting from emissions of fossil fuel combustion has sparked considerable interest in renewable energy and fuel production research, particularly energy derived from cellulosic ethanol, which is derived from biomass such as wood and grass. Cellulosic ethanol demonstrates a more promising future as a global energy source than corn-derived ethanol because it does not displace food crops, irrigation is not required, and chemical application rates are much lower than for annual crops, such as corn. Growing cellulosic biomass for energy can help reduce greenhouse gas emissions via carbon (C) sequestration and by reducing demand for fossil fuel production. The objective of this study was to investigate how land use change affects soil properties and selected soil C and nitrogen (N) dynamics among alternative cellulosic biofuel treatments at the Weyerhaeuser Alabama Cellulosic Biofuel Research site in west-central Alabama. Composite soils for characterization, along with forest floor, were collected at year 1 and year 2 after treatment establishment at 0-15cm and 15-30cm depths at six locations along three hillslope-riparian transects in five experimental watershed treatments. Decomposition of loblolly pine needles was assessed in each watershed using an in situ litter bag method. Seasonal in situ net nitrogen mineralization was measured using a sequential core method, and an anaerobic incubation for N mineralization potential of composite soils was performed in the laboratory. Results revealed high variability of soil properties and processes within these watersheds, along with no consistent treatment effects. This study provides baseline data for these watershed treatments for future studies.

Description
Keywords
switchgrass, forest soils, loblolly pine plantations, litter decomposition, nitrogen mineralization, agroforestry
Citation
Collections