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Extensive lignite mining in the Indian (Thar) Desert commenced within the past decade. Accompanying extraction of this valuable resource there have been visible, important environmental impacts. The resultant land degradation has prompted concern from both public and regulatory bodies. This research assesses the success of rehabilitation plans implemented to revegetate a lignite mine-disturbed area, near the village of Giral in western Rajasthan State. Rehabilitation success was achieved within the environmental constraints of this northwest Indian hot-desert ecosystem using a combination of: (1) backfilling (abandoned pits) with minespoil and of covering the backfilled-surfaces with fresh topsoil to a thickness of about 0·30 m; (2) use of micro-catchment rainwater harvesting (MCWH) technique; (3) soil profile modification approaches; (4) plant establishment methodologies; and (5) the selection of appropriate germplasm material (trees, shrubs and grasses). Preliminary results indicate that the resulting vegetative cover will be capable of self-perpetuation under natural conditions while at the same time meeting the land-use requirements of the local people. The minespoil is alkaline in nature and has high electrical conductance. The average content of organic carbon, N, P and K is lower than in the regional topsoil. However, the concentration of Ca, Mg, Na and total S in the minespoil is much higher than in the topsoil. Further, the spoil material has no biological activity. Enhanced plant growth was achieved in MCWH plots, compared to control plots, where minespoil moisture storage was improved by 18–43 per cent. The rehabilitation protocol used at the site appears to have been successful because, in addition to the planted species, desirable native invasive species have become established. This study developed methods for the rehabilitation of lignite mine-disturbed areas and has also resulted in an understanding of rehabilitation processes in arid regions with an emphasis on the long-term monitoring of rehabilitation success. Copyright © 2004 John Wiley & Sons, Ltd.

In the Indian desert, the economics of mining is second only to agriculture in importance. However, research on the rehabilitation of land disturbed by mining has only recently received serious attention. An attempt has been made to determine both the qualitative and quantitative success of rehabilitation plans used to revegetate limestone mine spoils in an area near Barna, northwest arid India. Rehabilitation success was achieved using a combination of rainwater harvesting techniques, soil amendment application approaches, plant establishment methods and the selection of appropriate germplasm material (trees, shrubs and grasses). It is expected that the resulting vegetative cover will be capable of self-perpetuation under natural conditions while at the same time meeting the land-use needs of the local people. The minespoils have adequate levels of the major nutrients (except P, Mo and Se) for proper plant and grazing animal health. Levels of organic matter are low whereas total B concentrations are exceptionally high. Also, the population of soil fungi, Azotobactor, and nitrifying bacteria is negligible. Enhanced plant growth was achieved in treated plots, compared to control plots, where spoil moisture storage was improved by 5 – 45 per cent. Due to the decomposition of farmyard manure and nitrogen fixation by planted leguminous plant species, the electrical conductance of treated mine spoils increased threefold, CaCO3 content decreased from 20·0 to 5·2 per cent, and organic carbon, P, K, and biological activity increased significantly. The rehabilitation protocol used at the site appears to have been successful because plant self-regeneration is occurring. The increased diversity of woody perennials resulted in ‘dominance’ being better shared among species and ‘evenness’ being increased within the plant community elements. The early to mid-successional trends are continuing for six years following initial rehabilitation. This study developed methods for the rehabilitation of lands mined for limestone and has also resulted in an understanding of rehabilitation processes in arid regions with an emphasis on the long-term monitoring of rehabilitation success. Copyright © 2000 John Wiley & Sons, Ltd.

Relationships between total Se and S or soluble SeO 4 and SO 4 7 in soils and tissue concentrations in alfalfa (Medicago sativa L.), under field conditions in the San Joaquin Valley of California, suggest that the rate of accumulation of Se in alfalfa may be reduced in areas where high Se and S concentrations in soils were measured. These data suggest that the balance between carbonate and sulfate minerals in soil may have a greater influence on uptake of Se by alfalfa than does the balance of SeO 4 and SO 4 in soil solution (...)

We examine the general topic of the biogeochemical cycling of trace elements and trace-element environmental concerns in surface coal-mine land reclamation1. Emphasis is placed on research trends and results from the arid and semi-arid regions of North America. We discuss the importance of conducting pre- and post-mining trace element inventories that both anticipate potential reclamation problems and help define possible long-term ‘ecosystem’ stability. Particular emphasis is placed on understanding the source, release and transport mechanisms, and fate of trace elements under various reclamation environments and how this relates to sustainable plant establishment and animal risk factors.

The processing of phosphatic shale near Pocatello, Idaho has a direct influence on the element content of local vegetation and soil. Samples of big sagebrush (Artemisia tridentata Nutt. subsp. tridentata) and cheatgrass (Bromus tectorum L.) show important negative relations between the concentration of certain elements (Cd, Cr, F, Ni, P, Se, U, V, and Zn) and distance from phosphate processing factories. Plant tissues within 3 km of the processing factories contain unusually high amounts of these elements except Ni and Se. Important negative relations with distance were also found for certain elements (Be, F, Fe, K, Li, Pb, Rb, Th, and Zn) in A-horizon soil. Amounts of seven elements (Be, F, Li, Pb, Rb, Th, and Zn) being contributed to the upper 5 cm of the soil by phosphate processing, as well as two additional elements (U and V) suspected as being contributed to soil, were estimated, with F showing the greatest increase (about 300 kg/ha) added to soils as far as 4 km downwind from the factories. The greatest number of important relations for both plants and soils was found downwind (northeast) of the processing factories.

The utility of DTPA (0.005M, pH 7.3) and EDTA (0.01M, pH 7.0) extractants for measuring the availability of Cu, Fe, Mn, and Zn from uncultivated A- and C-soil horizons to western wheatgrass (Agropyron smithii Rydb.), silver sagebrush (Artemisia cana Pursh), and above-ground biomass was assessed at 21 geochemically diverse sites in the northern Great Plains. Positive relationships between the extractable or the total concentration of these elements in soils to concentrations in plants, as measured by multiple regression, were limited. A-horizon DTPA-extractable levels of Fe and Mn were significant positive independent variables in the prediction of Fe and Mn levels in wheatgrass. C-horizon DTPA extractable levels of Mn and Zn were significant positive independent variables in the prediction of Mn and Zn sagebrush levels. Multiple regression techniques never gave significant relations between EDTA-extractable element levels and plant element levels; however, strong relations were observed between soil pH and metal concentrations in plants. The relation between plant metal concentration and A-horizon pH was always positive and apparently related to soil levels of metal carbonates. These data indicate that caution should be used in the formulation of regulations for plant available levels of these metals in Great Plains soils based solely on extractable levels.

Boron (B) content in mine soils and plants was assessed at 11 strip mines in the northern Great Plains, Powder River basin, and Green River coal regions. Except for unusually high B levels at one Wyoming mine, B levels in both mine soils and plants indicate that deficiency or toxicity conditions are minimal over this large geographic area. Relationships among mine-soil pH, organic-matter content, and hot-water soluble B, and B in plants are typical of those commonly reported in the literature. In addition, electrical conductivity (EC) of a water saturation extract of mine soil was positively correlated with B in mine soils. Regulations that suggest routine analysis for B to determine allowable levels in mine soils and rehabilitation plant species may be simplified. The more common measurements of pH and EC of mine soils should provide sufficient information to indicate potential B problem areas, where plant and mine soil analyses for B could then be performed.

A great diversity of techniques have been used to identify the anthropogenic and natural sources of atmospheric elemental emissions. Atmospheric gases and particulate matter, precipitation, surface waters, vegetation, and soils have all been analyzed in order to quantify elemental emissions, identify relative source contributions, and assess the region of influence of point and non-point emission sources. Typical techniques used in air pollution studies include source- based models, which utilize emission inventories and dispersion predictions, and receptor-based models, which use enrichment factors, chemical element balances, factor analysis, element concentration-distance trends, and stable isotope ratios.