source of environmental pollution and habitat destruction downstream. The nature of spoil materials varies widely, both in physical composition and chemical characteristics [3,4]. It also varies with geography, with spoils from the Appalachian region having more acid-generating capacity than those of the western spoils. This is because most of the western coalbeds have low sulfur and ash contents and are of similar geologic age, Cretaceous through early Tertiary. Regardless of their geological origin or geographic location, gob piles containing mine spoils are mostly characterized by materials that are texturally unsuitable to hold water or nutrients. Some older gob piles contain thin \"topsoil\" layers, which vary from clayey to sandy depending on the underlying rock type--shale or sandstone. Low levels of organic matter (OM) have been identified as the most common problem in mine gob spoils, which leads to poor soil health for plant growth and soil microbial life [5, 6, 7]. Mine gob spoils with low plant diversity are likely to cause a shortage of OM accumulation, which in turn leads to poor soil texture and structure [6]. Poor water-holding capacity (WHC), sediment erosion by wind and water, soil surface crusting, and cracking of soils are some of the adverse effects that result from poor spoil structure [8]. Although annuals and sparse clumps of grasses may be observed on gob piles, stabilizing vegetation is difficult to establish either artificially or naturally, and they mostly remain bare [9]. Rovegetation is complicated by a series of soil constraints including unsuitable pH, insufficient nutrient supply, metal toxicity, low water-holding capacity, and poor soil structure [10, 11, 12, 13]. On these slopes, seeds or seedlings are more likely to be washed away or buried by eroding material. Hence, to make a gob pile suitable for vegetation, the textural and chemical characteristics of spoils need to be manipulated to a point where they can sustain plant growth. This process is termed \"topsoiling\". [PERSON] et al. (1983) [9] define topsoiling as the reuse of original spoils as all or part of the new growing medium in reclamation. For topsoiling to work for the re-establishment of vegetation, (1) the water- and nutrient-holding capacity needs to be improved through the addition of OM and (2) the metal toxicity of the spoils needs to be decreased using sorbents that help in reducing the plant availability of metals. This is especially important because the added OM could potentially further solubilize metals, resulting in increased toxicity that prevents the establishment of vegetation. While manipulating the soil is the key to restoration, purchasing topsoil is cost-prohibitive. Therefore, it is important to develop inexpensive amendment strategies that could improve soil quality and aid in plant growth. Our study area was Carthage Coal field (CCF), located approximately 12 miles southeast of Socorro, NM, and 10 miles east of San Antonio, NM (Figure 1A,B). The coalfield lies on the east flank of the Rio Grande Rift in a series of small fault blocks that contain the coal-bearing units. Over 2 million short tons of coal were produced from mines within the CCF from 1882 to 1963 [13]. Mining at CCF was historically carried out by the San Pedro Coal and Coke, Carthage Coal/Carthage Fuel Company, and the Kinney mines. The demand for coal declined during The Great Depression, coupled with the introduction of newer and more affordable means to heat homes. Eventually, the rail operation from CCF was stopped in 1931 when coal mining was no longer profitable. Currently, CCF is full of gob piles that cannot support the growth of vegetation (Figure 1C).