Revegetation of degraded soils is crucial to prevent erosion and improve soil structure and quality. We aimed to elucidate the role of the root system of grasses on the reclamation of a soil constructed after coal mining. In Candiota city, in Brazil, perennial grasses (Hemarthria, Paspalum, Cynodon, and Brizantha) were cultivated for 103 months, when soil samples were collected from 0.00–0.30 m layer. The root development of these species substantially decreased in depth, reflecting soil restrictive conditions, as high soil penetration resistance, especially below 0.10 m, assigned to the use of heavy machinery during soil construction. Below 0.10 m depth, fine and flattened roots were observed, which penetrated through the cracks of compacted soil layers. Regardless of the soil layer, all plant species had a greater proportion of roots <0.49 than >0.50 mm diameter class, averaged 92 and 8%, respectively. Below 0.10 m depth, Brizantha increased the proportion of roots >0.50 mm diameter class, while the other grasses increased the proportion of roots <0.49 mm diameter class. The highest root density, volume, and length observed for Brizantha along the soil profile indicate its high potential to improve physical attributes and therefore the quality of the constructed soil.
Part of the book: Grasses as Food and Feed