Growth of Hard Red Spring Wheat in Crude Oil Contaminated Soils Treated By Thermal Desorption.

Crude oil spills introduce petroleum hydrocarbons (PHC) into the environment that adversely affect plant growth.  Thermal desorption (TD) is an efficient and relatively fast technique for treating PHC contaminated soil wherein the soil is heated to enhance contaminant volatilization to separate PHCs from soil. The objectives of this research were to examine plant response and nutrient dynamics in wheat grown in TD treated soil.  A greenhouse study was conducted growing Barlow hard red spring wheat (Tritium aestivum L.) in soil mixtures incorporating contaminated, TD-treated soil.  Each 4 kg pot was filled with 100%, 90%, 70%, 40%, or 0%, by weight, of contaminated, TD-treated soil; the remaining weight for each pot was composed of native, non-contaminated A horizon.  Total biomass and grain yield were lower in all treatments incorporating TD treated soil, with the 100% treatment producing only half as much grain as the native topsoil. Grain protein content from the 100% treated soil was significantly lower, up to 30%, than all other treatments.  Plant available N at time of harvest was up to 25% lower in treatments with TD treated soil than in the native topsoil, despite producing less biomass.  Since N, P, and K levels were standardized at time of planting, these discrepancies cannot be ascribed to nutrient levels but are likely associated with transport mechanisms.  These results indicate that utilizing TD for remediation in agricultural systems without any additional management may reduce grain yield and quality.