Resumen

STUMPF, Lizete et al. Capability of grass in recovery of a degraded area after coal mining. Agrociencia [online]. 2014, vol.48, n.5, pp.477-487. ISSN 2521-9766.

Surface coal mining causes an intense topographic and hydrologic change in the area with suppression of local vegetation, degrading the environment. One main problem presented by the rehabilitated soil refers to physical disruption of the soil, which delays the regrowth of plant species in the mining area. The objective of this study was to evaluate the influence of four grass species in the retrieval of the rehabilitated soil's physical properties at a recovered coal mine area in Candiota, Rio Grande do Sul State, southern Brazil. With the data an ANOVA was performed and treatments means were compared using Tukey test (p ≤0.05). The treatments were: T1-Hemarthria altissima; T2-Paspalum notatum; T3-Cynodon dactylon; T4-Urochloa brizantha; a rehabilitated soil without vegetation cover was used as control. Preserved soil samples after 78 months were collected in the 0.00-0.10 m and 0.10-0.20 m layers to determine bulk density, total porosity, macroporosity, microporosity and available water capacity. The process of rehabilitation of coal mined areas was slow due to the high degree of degradation that occurs during the extraction of coal and the topographic recovery of the area, adversely affecting the structural quality of the soils. The assessed grasses showed potential to reclaim these areas, since improvements were observed in the values of the soil attributes over time, especially in the 0.00-0.10 m layer. After 78 months of evaluation, U. brizantha showed the higher potential to recover the physical properties of the compacted rehabilitated mine soils.

Palabras llave : Hemarthria altissima; Paspalum notatum; Cynodon dactylon; Urochloa brizantha; rehabilitated soils; physical properties.