Initial recovery of organic matter of a grass-covered constructed soil after coal mining

Abstract

Revegetation is essential to improve the quality of constructed soils. This study investigated effects of perennial grasses on total organic carbon (TOC) stock, organic matter (OM) fractions and on quality of a recently constructed soil, after coal mining. Soil samples were collected from the 0.00-0.03 m layer two years after the beginning of the experiment. The treatments consisted of Cynodon dactylon cv vaquero (T1); Urochloa brizantha (T2); Panicum maximun (T3); Urochloa humidicola (T4); Hemarthria altissima (T5); Cynodon dactylon cv tifton (T6); bare constructed soil (T8); and natural soil (T9). The treatments with grass species increased the TOC stock by 57 % and increased the OM lability in comparison with T8. Higher C accumulation in the coarse and free light fractions and a higher C management index were observed in T2 and T3, indicating greater suitability of these species for the initial recovery of OM of the constructed soil.