TITLE:
Relating Cone Penetration and Rutting Resistance to Variations in Forest Soil Properties and Daily Moisture Fluctuations
AUTHORS:
Marie-France Jones, Paul A. Arp
KEYWORDS:
Soil Resistance to Penetration, Cone Index, Soil Moisture, Texture, Coarse Fragments, Organic Matter, Weather Records, Hydrological Modelling, Soil Trafficability, Rutting Depth, Recreational Vehicles
JOURNAL NAME:
Open Journal of Soil Science,
Vol.7 No.7,
July
17,
2017
ABSTRACT: Soil resistance to
penetration and rutting depends on variations in soil texture, density and
weather-affected changes in moisture content. It is therefore difficult to know
when and where off-road traffic could lead to rutting-induced soil
disturbances. To establish some of the empirical means needed to enable the
“when” and “where” determinations, an effort was made to model the soil
resistance to penetration over time for three contrasting forest locations in
Fredericton, New Brunswick: a loam and a clay loam on ablation/ basal till, and
a sandy loam on alluvium. Measurements were taken manually with a soil moisture
probe and a cone penetrometer from spring to fall at weekly intervals. Soil
moisture was measured at 7.5 cm soil depth, and modelled at 15, 30, 45 and 60
cm depth using the Forest Hydrology Model (ForHyM). Cone penetration in the
form of the cone index (CI) was
determined at the same depths. These determinations were not only correlated
with measured soil moisture but were also affected by soil density (or pore
space), texture, and coarse fragment and organic matter content (R2 = 0.54; all locations and
soil depths). The resulting regression-derived CI model was used to emulate how CI would generally change at each of the three locations based on
daily weather records for rain, snow, and air temperature. This was done
through location-initialized and calibrated hydrological and geospatial
modelling. For practical interpretation purposes, the resulting CI projections were transformed into
rut-depth estimates regarding multi-pass off-road all-terrain vehicle traffic.