Experimental Measurement of Biomass Impact On Soil Strength.

Studies of vehicle impacts on soil compaction and soil influence on vehicle mobility are numerous; however, most often the soils involved are without vegetation or the amount of vegetation is not considered. This research aims to look at the effect of vegetated soils on soil strength. The approach includes a series of experiments where above and below ground biomass was measured along with soil strength.  Test sections included different types of vegetation in various growth stages and subjected to land treatments such as trafficking, burning, and haying/cutting.  Soil types included sandy and silty clay mixtures, and vegetation was primarily Kentucky Bluegrass, Perennial Rye grass and a Perennial Ry grass mix. Strength measurements were made with several instruments including a Goodwin drop cone, Clegg Impact Hammer, Trafficability Cone Penetrometer, Pilcon shear strength, and Dynamic Cone Penetrometer. The biomass measurements included above and below ground density as well as classification of root length and diameter. Correlations and comments on the relationships between biomass measurements and the different soil strength measurements will be presented.