|dc.description.abstract||Soil moisture limits agricultural production in semi-arid prairies and is a key
hydrological factor affecting the fate and transport of pollutants in soils. Spatial and
temporal variability in soil water requires monitoring many locations to capture the
salient features of soil water in the field. The objective of this study was to examine
whether there are temporally stable soil moisture patterns in a field and whether a
representative moisture benchmark site can be identified from these patterns. The
experiments were conducted on a black soil at Alvena, northwest of Saskatoon, Canada.
Soil moisture was monitored at 95 measurement sites with a portable Capacitance Probe
(CP) along a 612m rolling transect, from April to September in 2001 and 2002.
Temporal stability of spatial patterns in soil moisture for depths of 30, 60, 90, 120 and
160cm were determined using temporal means and standard deviations of the differences
between individual and spatial average values of soil moisture along the transect. The
spatial patterns of soil water storage were stable in different locations for each depth.
Spatial variations in soil moisture with daily soil moisture means of >0.20 and <0.20
showed poor correlations with soil texture (R2 < 0.1) and topographical variables (R2 <
0.3). Clay content showed the least amount of control of spatial patterns with only one
day with R2 (=0.08) greater than 0.01. Coefficient of variation and standard deviation of
soil moisture both decreased with increasing soil moisture. For depths of 30, 90, and
120cm, benchmark sites had a difference of less than 1% in soil moisture storage from
both measured field mean and a composite sample obtained using the conventional
random sample method, indicating the three methods are equivalent to each other. Soil
moisture benchmark sites identified in this study represent field mean soil moisture||en_US