Degree Type

Thesis

Date of Award

2016

Degree Name

Master of Science

Department

Agronomy

Major

Soil Science

First Advisor

Michael Castellano

Abstract

Reconstructed prairies can be a useful tool in combating climate change by acting as a sink for carbon (C) and nitrogen (N). However, little is known about where C and N gains occur in the soil matrix, and in turn whether they accumulate in pools characterized by relatively long or short mean residence time. To answer this question, a reconstructed prairie chronosequence spanning 21 years was used to observe changes in chemically and physically protected C and N pools. As these soils were finely textured, edaphic properties such as non-crystalline iron and polyvalent cations were also examined for associations with C and N pools. While there was a significant increase in both total soil C and N over time, pools chemically bound to silt/clay outside of microaggregates served as the largest stock in which new C and N was stabilized. Physically protected particulate organic matter did not increase with prairie age, but microaggregate silt/clay C and N concentrations were correlated with microaggregate ammonium oxalate extractable iron. These results contrast previously held understandings of microaggregate turnover under no-till soil environments such as reconstructed prairie. Future research must investigate why C and N stocks in reconstructed prairies are much less than remnants, and whether improved prairie management can affect physical or chemical protection of organic matter.

Copyright Owner

Shane Michael Bugeja

Language

en

File Format

application/pdf

File Size

60 pages

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