petroleum contamination of soil is a serious problem throughout the oil producer countries. vegetation may play an important role in the biodegradation of toxic organic chemicals in soil. for petroleum compounds, the presence of rhizosphere micro flora may accelerate biodegradation of the contaminants. in a greenhouse study, petroleum contaminated soil were treated using phytoremediation . the ...

The relationship between toxicity and soil contamination must be understood to develop reliable indicators of environmental restoration for bioremediation. Two bacterial rapid bioassays, SOS chromotest and the umu test with and without metabolic activation (S-9 mixture), were used to evaluate the genotoxicity of petroleum hydrocarbon-contaminated soil following bioremediation treatment. The soi...

Our objectives were to: (1) characterize SOC (0 to 1.53-m) within a 37-ha field typical of the Palouse region in eastern Washington; and (2) assess correlations and how much SOC variance could be accounted for by terrain and soil variables. A systematic, non-aligned grid of 177 georeferenced sample locations was established at the Washington State University Cook Agronomy Farm (CAF) near Pullma...

Cyanide is commonly found as ferrocyanide [Fe(II)(CN)(6)](-4) and in the more mobile form, ferricyanide [Fe(III)(CN)(6)](-3) in contaminated soils and sediments. Although soil minerals may influence ferrocyanide speciation, and thus mobility, the possible influence of soil enzymes has not been examined. In a series of experiments conducted under a range of soil-like conditions, laccase, a pheno...

A simulation study was conducted to evaluate three terramechanics methods used for predicting single wheel performance of small vehicles on granular terrain. Traditional Bekker-type terramechanics methods do not consider the soil profile, the soil dynamics, or the transient wheel dynamics, which can be important factors in vehicle performance. The ‘dynamic Bekker’ method used to overcome these ...

Drawing on academic literature and personal experience, the authors highlight trends emerging from sustainable agriculture efforts in developing countries, involving research institutions, action agencies, and communities, to provide recommendations for advancing a soil health movement. They argue that multi-disciplinary and -institutional efforts on soil health that link research, practice, an...

Preventive and/or manipulative practices will be needed to maintain soil's biological, physiochemical, nutritional, and structural health in natural, managed, and disturbed ecosystems as a foundation for food security and global ecosystem sustainability. While there is a substantial body of interdisciplinary science on understanding function and structure of soil ecosystems, key gaps must be br...

The potential of grazing lands to sequester carbon must be understood to develop effective soil conservation measures and sustain livestock production. Our objective was to evaluate the effects of grazing on soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) in Typical steppe and Desert steppe ecosystems, which are both important grassland resources for animal grazin...

Microbes are the unseen majority in soil and comprise a large portion of life's genetic diversity. Despite their abundance, the impact of soil microbes on ecosystem processes is still poorly understood. Here we explore the various roles that soil microbes play in terrestrial ecosystems with special emphasis on their contribution to plant productivity and diversity. Soil microbes are important r...