D. F. Amos's research while affiliated with Virginia Tech (Virginia Polytechnic Institute and State University) and other places

... Soil compaction restricts plant root development and reduces the available water holding capacity of the growth medium layer. Daniels & Amos (1981) found compaction was the major soil factor limiting long-term revegetation success at a reclaimed mine site in Virginia. According to Straker (2019), most soils with a dry density above 1,600 kg/m 3 (~80 to 85% of standard Proctor maximum dry density) will inhibit plant root development. ...

... Raw mine spoils from the Wise Formation typically have unexpectedly high levels of acid-extractable P (Daniels and Amos, 1982), but subsequent weathered and oxidized mine soils consistently have lower levels of extractable P, primarily as a result of long-term leaching, oxidation, and P-fixation mechanisms (Howard, 1979). Phosphorus is held in unavailable forms via specific adsorption by free Fe and Mn oxides at pH <6.0 and by carbonate surfaces at higher pH levels. ...

... In 1982, the sawdust and 224 Mg ha· 1 SS treatment plots contained the highest percentages of organic matter. The native soil treatment was a mixture of the A, E, B, C, and Cr horizons, therefore, SOM content was substantially lower than other treatments and actually no higher than the control treatment (Daniels et al., 1983). Soil organic matter in the sawdust-treated plots declined by almost one-half, while the plots treated with 112 Mg ha· 1 SS treatments declined only slightly over the past 16 years. ...

... However, little is known about the development of reclamation mine soils with regard to buried mine spoil and metal uptake. Topsoil salvage is recommended for reclamation (Skousen et al., 2011), however fragmented geologic materials (mine spoil) may also be incorporated (Daniels and Amos, 1985). It may be that the 1 m soil-ripping method may inadvertently mix buried spoils where buried rock and spoil are approximately 45 cm below the surface. ...

... Fine-textured soils and mine spoils have a tendency to form surface crusts (Sheoran et al. 2010). Although the seeds in this study were covered only by millimetres of media, the crust may have prevented seedlings from emerging through the surface (Forcella et al. 2000), or inhibited water infiltration (Daniels and Amos 1985). However, the OM treatment was not made of particularly fine material, so it seems unlikely that this was the reason for a crust to form. ...

... This research examines five representative pedons from each of six fluvial surfaces in the Little River valley and focuses on the clay mineralogy and total chemistry of the whole soil (<2 mm) and fine sand (0.125-0.250 mm) fractions of the most well-developed subsoil horizon per profile. Within this design, whole soil properties of interest consist of variables known to be effective chronosequence parameters in the region [12,19,21,23,24,26,27] and include the molar ratio of bases to alumina (Bases/Al 2 O 3 ), dithionite-extractable Fe (Fe D ), and the ratio of dithionite-extractable to total Fe (Fe D /Fe 2 O 3 ), among other properties. The elemental oxide concentrations of K 2 O, Na 2 O, and MgO comprise the variables measured for the fine sand fraction. ...

... Clayey mine soils are often dense, cloddy, and sticky when wet, thereby restricting water penetration, water movement, and root development. The clay-sized fraction of mine soils may contain minerals not typically found in clays of natural soils due to the effects of rock blasting (Howard 2017). The best soils for plant growth are those with loamy textures which have moderate amounts of sand, silt, and clay. ...

... The topsoil substitution allowance is generally based upon conventional soil chemical tests and an estimation of the post-blasting texture and rock content of the resultant spoils (Daniels & Zipper, 1997). Since the native forest soils are typically acidic, infertile, and high in coarse fragment content, historically it has been rather simple to demonstrate superior soil chemical properties such as higher pH and extractable Ca and P from the relatively unweathered rock spoils (Daniels & Amos, 1982). However, post-placement mine soil compaction is a significant limiting property over time (Haering et al., 2004). ...

... Documenting pedogenic changes resulting from the conversion of forests to pastures is not new research, but the vast majority of previous research is in the tropics, only considers decadal timescales (e.g. Daniels et al. 1983, Fearnside et al. 1998, Ellingson et al. 2000, Chacón et al. 2009, Braz et al. 2013, Zucca et al. 2010, Hamer et al. 2013, Goudie 2013, and is largely focused on degradation of physical, chemical, and biological properties (i.e. erosion, compaction, nutrient and organism depletions). ...

... In addition, effective quartz dissolution requires excess water in the system (Wray & Sauro, 2017). The slow hydrolytic dissolution of quartz demands solutions depleted in H 4 SiO 4 and the absence of coexisting silicates (Howard, Amos, & Daniels, 1995;Melfi et al., 1979;Wray & Sauro, 2017). Thus, intense desilication most likely proceeded more effectively after transformation of muscovite and kaolinite into gibbsite. ...