Chapters authored
Reclamation of Soils Degraded by Surface Coal Mining
The largest Brazilian coal mine, called Candiota mine, is located in South Brazil, with an estimated reserve about 1.2 billion tons. Since late 2003, an experiment located at a reclaimed site in a coal mining area was conducted, in which a research group from the Federal University of Pelotas has been conducting a long-term experiment on soil quality with different plants species, such as Hemarthria altissima, Paspalum notatum cv. Pensacola, Cynodon dactylon cv. Tifton, and Urochloa brizantha. After 8.6 years of revegetation, soil samples at 0.20 depth were collected in minesoil and natural soil to determine physical attributes, and the organic carbon content. After 10.9 years of revegetation, soil samples at 0.10 m depth were collected to determine the biological attributes. According to the research results, it can be seen that the recovery of minesoil was more effective after 8.6 years of revegetation only in the physical condition up to 0.10 m depth. However, all soil physical attributes and organic matter content are still below the levels observed in the natural soil. The biological attributes after 10.9 years of revegetation have not yet been sufficient to restore a mites and springtails population close to the natural soil.
Part of the book: Mining Techniques
Physical Quality of Soils in a Toposequence of a Forest Fragment under Livestock Activity in a Watershed in South Brazil
The conservation of native forests is fundamental to the preservation of hydric resources in the landscape. The use of animals in forest fragments has resulted in degradations in the soil, resulting in the grating of these. Thus, soil classes were studied and physical parameters of forest soils were evaluated in areas without and with cattle grazing in the “Arroio Pelotas” watershed, Pelotas, Rio Grande do Sul, extreme south of Brazil. The results were submitted to statistical analysis with the Kruskal–Wallis nonparametric test with a significance level of 5%. The means of the physical parameters of soil in the same toposequence and layers with and without the presence of livestock were compared. By analyzing soil physical attributes (density, macroporosity, and microporosity) it can be seen that the structural quality of the soil is affected by the access of animals inside the forest fragments, especially in the upper layer of the soil (0–5 cm deep). In forest fragments without access to animals, the physical structure of the soil presented the best conditions of macroporosity and, consequently, greater protection of nutrients, microorganisms, and water resources. Therefore, it is concluded that conservation by the isolation of protective forests in rural property planning benefits the quality of forest soils.
Part of the book: Forest Degradation Under Global Change
Evolution of a Technosol Cultivated with Perennial Grass, over 15 Years: Potential Use as Carbon Sinks
In this study, we investigated the increase in carbon in the surface layer of a technosol, promoted by perennial grasses, and its implications for the recovery of land degraded by coal mining in southern Brazil, and its potential as carbon sinks. To monitor the recovery process of soils constructed after coal mining, a randomized block experiment was implemented in 2003, with several species of perennial grasses, in a coal mine in southern Brazil. Over 15 years of monitoring, the species Hemarthria altissima and Urochloa brizantha showed the best rates of incorporation of organic matter and soil decompaction capacity. To evaluate the efficiency of these species over time in recovering these technosols, polynomial regression models were adjusted to total organic carbon (TOC) and soil bulk density (Bd) data. The ability of these species to increase organic soil carbon stocks (SCS) was also estimated. The results verified showed that the use of perennial grasses in the recovery processes of these areas can, over time, promote an increase in TOC (425%) and reduce Bd. In this sense, it is believed that technosols constructed in mining areas can become excellent carbon sinks if properly designed for this purpose.
Part of the book: Technologies in Mining [Working title]