Effects of vegetation and fertilization on weathered particles of coal gob in Shanxi mining areas, China

Combined application of sewage sludge and chemical fertilizer in weathered particles of coal gob (WPCG) was studied by pot-scale trials. The accumulation of available nutrients and weathering process of coal gob piles were also investigated by field trial. It was showed that combined application of sewage sludge and chemical fertilizer increased yields of tall fescue, improved WPCG fertility especially its biological fertility. After application of sewage sludge, the microbial biomass carbon, urease activity and total microorganism population were, respectively, increased by 0.3-2.4, 1.8-2.8 and 34-150 times. Heavy metals did not accumulate in tall fescue after application of sewage sludge in WPCG. Available nutrients were accumulated in topsoil eight years after reclamation in the field trial. Moreover, the effects of biological weathering exceeded that of natural weathering in coal gob piles. The percentage of coal gob particle diameter smaller than 3 mm in the reclamation sites was increased by 85-203%, but 30% in the un-reclaimed sites. While that of greater than 10 turn in the un-reclaimed sites was decreased by 19%, however, 62-74% in the reclamation sites. It was concluded that combined application of sewage sludge and chemical fertilizer could help quickly establishing a self-maintaining vegetation system in the primary process of reclamation. (c) 2005 Elsevier B.V. All rights reserved.