Chemical characteristics of a constructed soil and their effects on root development of perennial grasses

Abstract

This study aims to characterize the chemical condition of the constructed soil after coal mining and to evaluate its influence on root development of perennial grasses. The study was conducted in a coal mining area located in Candiota/RS. The soil was constructed in January/February 2003 and the experiment carried out in November/December 2003. Plant species evaluated were Hemarthria altissima, Paspalum notatum cv. Pensacola, Cynodon dactylon cv Tifton and Urochloa brizantha. The soil and root sampling was made in July 2012, 48 soil samples to determine constructed soil chemical attributes and 16 soil monoliths to determine the root attributes of plant species were collected. The use of plant species in recovery of constructed soils after coal mining should consider the depth of the soil layer replaced on the mine spoils. Plant species decreased root development mainly in the layer of 0.20-0.30 m characterized by extremely low pH and high potential acidity, possibly due to the sulfurization process, caused by the presence of pyrite.