SURFACTANT AND SOIL FIXATIVE TREATMENT OF FIRE-IMACTED SOILS TO IMPROVE WETTABILITY AND REDUCE EROSION
The shallow soil profile consisted of a black, burned soil from 0-2 cm, a light tan mineral soil from 2-3.5 cm, and a medium tan mineral soil below 3.5 cm across all plots. Results of the water drop tests showed that the uppermost, black soil layer tended to be very hydrophilic (instant drop adsorption) throughout the study. The light tan soil layer was consistently hydrophobic (drop adsorption greater than 30 minutes) in all plots before surfactant application.The lowest, medium tan layer, below 3.5 cm, tended to be hydrophilic in most cases. Surfactant application reduced hydrophobicity in the tan soil layer in some locations, and roughly correlated with amount of surfactant applied. The effect was uneven, even after rainfall. The soil fixative application was very effective in preventing erosion throughout subsequent heavy rain events. Reduction of hydrophobicity below the fixative layer was also uneven in the tan soil. Oak seedling germination was greatest in the fixative-treated plot. Additional hydrophobicity tests will be performed after this spring's snowmelt.