干旱区生态环境知识资源中心

Soil respiration was usually used to be the sensitivity indicators of contamination due to their importance in cycling of organic matter in soils. In order to understand the effect of environmental factors on the bioremediation of crude oil contamination at arid and semi-arid regions, the dynamics of soil respiration and degradation rate of total petroleum hydrocarbons (TPH) were determined using a 59 days laboratory incubation experiment under a range of crude oil contaminated levels, soil water contents and C:N ratio in soils. Results showed that crude oil contaminated soil of lower C:N ratio (6:1) had significant greater soil respiration and TPH degradation than that with the higher C:N ratio (25:1). Although the TPH degradation rate decreased with the increase of contamination levels, the soil respiration and TPH degradation of contaminated soil is higher than the uncontaminated soils, especially when the contamination level was more than 20 g kg(-1). Unlike the factors of C:N ratio and contamination levels, the soil water content has no significant effect on soil respiration and TPH degradation. These results indicated that low nitrogen concentration rather than soil water content was the main limiting factors for soil respiration and TPH degradation in contamination soils at Northwest China when the soil water content reach 20%.