TITLE:
Re-Examining Field-Surveyed Variations in Elevation and Soil Properties with a 1-m Resolution LiDAR-Generated DEM
AUTHORS:
Kamille Lemieux, Paul A. Arp
KEYWORDS:
Field-Elevation Survey, LiDAR 1-m DEM, Flow Channels, Depth-to-Water, Soil Properties, Factor Analysis
JOURNAL NAME:
Open Journal of Soil Science,
Vol.13 No.9,
September
28,
2023
ABSTRACT: This article
presents a 2017 LiDAR-DEM guided 1-m resolution examination of field-surveyed elevation
and soil property variations (5 × 5 m spacings) conducted in 1977 across a hummocky
New Brunswick field used for potato production. This examination revealed that the
field incurred minor elevation differences were likely due to upslope erosion, as revealed
through increasing Sand % and CF % with increasing elevation, and increasing Silt
% along low-lying areas. Soil moisture, field capacity, permanent wilting and nitrate
nitrogen (NO3-N) also increased at downslope locations. Directly as well
as indirectly, soil pH, ammonium nitrogen (NH4-N), Caesium137 (Cs137) and Mehlich-3 extracted Ca, Mg, K, Fe, Mn, Cu, and Zn were likewise
affected by topographic location. Factor analyzing these variables led to: 1) a Soil Loss Factor that captured 24% of the textural
variations; 2) a Soil-Cropping
Factor accounting for 16% of the N, P, K, Ca, Mg, Mn variations; 3) a Soil Organic Matter (SOM) Factor relating 9% of the
in-field variations for SOM, Fe, Zn, Cu to via
organo-metal complexation and low NO3-N retention. Many of the topographic variations increased or decreased
with the metric DEM-projected depth-to-water index (DTW) index. This index
was set to 0 along DEM-derived flow channels with minimum upslope flow-accumulation
areas of 0.1, 0.25, 0.5, 1 or 4 ha. Among these, the DTW > 4 ha threshold was
useful for reproducing the textural variations, while the DTW > 0.25 ha threshold
assisted in capturing trends pertaining to moisture retention and elemental concentrations.