Reclamation of a Degraded Coal-Mining Area with Perennial Cover Crops

Abstract

Studies addressing the potential of grass roots in improving the structural quality of constructed minesoils are not frequent in the literature, although they are essential for understanding the re-establishment of soil functions in the environment. The objective of this study was to quantify the root attributes of the species Urochloa humidicola, Panicum maximum, and Urochloa brizantha and relate them to the physical properties of a constructed minesoil in reclamation of an area degraded by coal mining. The study was performed in a field experiment in a coal mining area located in southern Brazil. Soil samples were collected, five years after experiment installation, to determine bulk density, macroporosity, distribution of water stable aggregates expressed in different size classes, mean weight diameter of water stable aggregates, and organic carbon content, as well as for chemical characterization. Root sampling was performed by the monolith method to a depth of 0.30 m. Results confirm the hypothesis that the root system of the perennial grasses studied positively contributes to recovery of the constructed minesoil in the 0.00-0.10 m layer after 58 months of revegetation. The higher percentage of large aggregates, higher bulk density, and lower macroporosity in the subsurface indicate the presence of degraded layers, negatively influencing the development of the grass root system. Urochloa brizantha exhibited the largest root matter in the surface layer, influencing the breakdown of the large and cohesive aggregates, transforming them into smaller crumbly aggregates. In the 0.10-0.20 m layer, Urochloa humidicola showed greater volume and root length in relation to other species; nevertheless, changes in soil physical properties were not observed, showing that the time span of the root growth of the species was not sufficient to provide improvements in the subsurface layers.

Nitrogen recovery in reclaimed mine soil under different amendment practices in tandem with legume and non‐legume revegetation: A review

“…In reclaimed mine soil (RMS), examining the N dynamics can be especially informative for understanding recovery stresses restricting revegetation success. Soil horizons observed in RMS include A and/or C, and the B horizon cannot be formed because of the pedogenically young age (<10 years) of the constructed mine soils (Paulleto et al, 2016; Sencindiver & Ammons, 2000). However, the A horizon is quite thin and very different to the naturally formed soils (Cao et al, 2015; Shrestha & Lal, 2008; Wick et al, 2013).…”

Floral Distribution of a Sub-Bituminous Coal Dumpsite in Enugu, Nigeria

“…Drawing from the lessons of the occurrence of the devastation by coal mining on the ecosystem (in abandoned mined lands) and its subsequent revegetation from different regions of the world (Baig, 1992;Skousen et al, 1994;Sheoran et al, 2010;Yang et al, 2015;Pauletto et al, 2016;Buta et al, 2019), it was essential to examine how coal mining and its concomitant wastes have impacted the floral distribution in the Coal Camp/Ogbete area. We evaluated the plant diversity by (1) comparing the remnant species in the polluted coal site (IZ) and an undisturbed site (CZ) and by the assessment of the conservation status of the species within the study area.…”

Potential Economic Value of Water Resource Sustainability for Sustainable Environment: A Case Study in South Sumatra, Indonesia

“…This process is also capable of reducing erosion and protecting soil degradation [35]. However, possible occurrence is greatly decreased by cultivating legium cover crops (LCC) in early vegetation stages [36][37][38][39][40][41]. Based on this study, mine reclamation demonstrated the robust capacity to restore environmental degradation, but was unable to completely reform the depleted water resources.…”