The effect of interactions between soil compaction and phenol contamination on plant growth characteristics: Implications for scaling bioremediation at industrial sites

Abstract

In phenol contaminated soils from an industrial site, soil compaction and soil chemical contaminants influenced germination, emergence, and early plant growth (roots and shoots) for Thrift (Ameria maratima) and Blackbutt oats (Avena sativa). The specific effects were of soil compaction (low, 100 psi and high, 800 psi) at two concentrations of phenol (biotreated, ∼200 mg kg−3; untreated, ∼1150 mg kg−3). Plant responses to compaction and phenol varies between the two species. Emergence of Thrift showed greater sensitivity to increasing soil compaction but only under high phenol concentrations. Low phenol inhibited Thrift root length, as is the case with Balckbutt oats, although high phenol had no significant impact on Thrift. While shoot length of Blackbutt oats is not significantly affected by increasing soil compaction, it is negatively impacted at the increased phenol concentrations in the untreated soils indicating an interaction effect with compaction. This is the first study that examines the impact of soil contamination on oats. The oat variety tested had known drought tolerance and hardiness indicating an ability to withstand compaction, and which may explain those characteristics. Thrift was most resistant to contamination which is consistent with its previously reported tolerance of pollutants. Implications of the study are that Blackbutt oats represent a potential candidate species for land rehabilitation under high compaction conditions such as at degraded soil sites at decommissioned mining operations, polluted industrial sites, or degraded (compacted) agricultural land.