Plant and fertiliser effects on rhizodegradation of crude oil in two soils with different nutrient status.

Unterbrunner, Reinhard; Wieshammer, Gerlinde; Hollender, Ursula; Felderer, Bernd; Wieshammer-Zivkovic, Michael; Puschenreiter, Markus; Wenzel, Walter W.

Soils and sediments polluted with crude oil are of major environmental concern on various contaminated sites. Outdoors pot experiments were conducted to test the phytodegradation potential of common reed ( Phragmites australis) and poplar ( Populus nigra × maximowiczii) in fertilised and non-fertilised control treatments. Two topsoils (E, G) of different texture were mixed with crude oil. Soil analysis included hydrocarbon (HC) measurements, detection of labile phosphorus and mineralised nitrogen as well as dehydrogenase activity. Increased HC degradation by native soil biota was clearly related to higher P availability in soil G and to fertilisation in soil E. Except of the non-fertilised common reed treatment, plants did not enhance crude oil degradation. We found even inhibited degradation of high molecular weight HC in the presence of plants together with declining labile phosphorous concentrations due to planting on soil E. Native soil biota were able to use the whole range of crude oil compounds (C10 to C60) as a carbon source in the presence of sufficient nutrient concentrations in soil. This study is the first to show that reduced HC degradation in the higher molecular weight crude oil fraction (C20 to C40) is likely to be a consequence of decreased phosphorus availability for microorganisms in the plant rhizosphere.

PLANT-soil relationships; PETROLEUM; PLANTING; SALICACEAE; SOIL testing; ORGANIC compounds; PLANT roots; SOIL pollution; INDUSTRIAL contamination

Plant & Soil, 2007, Vol 300, Issue 1/2, p117

0032-079X

Academic Journal

10.1007/s11104-007-9394-2