Wl. Powers et al., SPATIAL SERIES ANALYSIS OF HORIZONTAL CORES TO CHARACTERIZE TRACER PATTERNS IN SOIL PROFILES, Soil Science Society of America journal, 61(4), 1997, pp. 1018-1023
Surface topography, plant canopy, plant root distribution, and soil pr
eferential flow paths cause variability in downward movement of agrich
emicals in soil. To better understand this variability, tracers are of
ten applied to the soil surface and their signatures (concentration pa
tterns) are examined, To characterize Br- signatures within a Crete si
lt loam soil (fine, montmorillonitic, mesic Pachic Argiustoll), potass
ium bromide was applied to the soil surface at 200 kg ha(-1). Four set
s (two sets in June and two sets in August) of four 6.1-m horizontal c
ores were taken in a vertical plane, perpendicular to corn plant rows
at 20-, 40-, 80-, and 120-cm depths, Each 6.1-m core was divided into
120 5.1-cm sections and analyzed for Br-. Spatial series analyses were
used to identify deterministic and combined deterministic-stochastic
models that described the cyclic nature of Br- concentrations at each
depth, Periods for these sinusoidal cycles generally corresponded to t
he distance between plant rows or the distance between the wheel track
s of field equipment.