Long-Term Effects of Rock Type, Weathering and Amendments on Southwest Virginia Mine Soils

This study measured the effects of spoil type and amendments on Appalachian mine soil properties over time. The Controlled Overburden Placement Experiment was installed in 1982 in two parts, the Rock Mix (RM) Experiment compares mixes of sandstone (SS) and siltstone (SiS) spoils while the Surface Amendment (SA) Experiment compares a fertilized control (CON), sawdust (SD at 112 Mg ha⁻¹), topsoil (TSâ 15 cm), and biosolids (BS) at 22, 56, 112 & 224 Mg ha⁻¹. Both experiments were sampled in 2008 and compared with historical data. After 26 years, all RM treatments had higher silt+clay and decreased sand. Mine soil pH and electrical conductance (EC) were lower in high SS spoils and overall pH was lower and EC higher in surface layers. Fe-oxides increased over time and adversely affected extractable P. Exchangeable cations and total N increased in all treatments. Annual C-sequestration rates were 0.51 Mg ha⁻¹ for 1:1 SS:SiS and 0.32 Mg ha⁻¹ for SiS. In the SA experiment, extractable P and exchangeable cations increased over time in organically amended plots. The CON and TS sequestered C at 0.54 Mg ha⁻¹ and 0.87 Mg ha⁻¹ annually while higher BS and SD treatments lost C, but mobilized significant C into their subsoils. In the SA, an apparent C retention maximum of 30-35 Mg ha⁻¹ was noted. Overall, rock type and amendment effects were still evident after 26 years and the long-term benefits of organic amendments were reflected in sustained higher C, exchangeable cations, total N and P levels.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2012

Author dc:creator

• Nash, Whitney Laine

Chair dc:contributor.committeechair

• Daniels, W. Lee

Committee members dc:contributor.committeemember

• Strahm, Brian D.
• Burger, James A.
• Zipper, Carl E.

• pedogenesis
• topsoil substitute
• revegetation
• mine spoil

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-05142012-123606

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/42657