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<br />before- and after-run moisture contents of these soil samples show relatively <br />low spatial variability. Standard deviations are about 1 to 2 percent by <br />volume for before-dry-run moisture contents (figs. 5A and 6A) and about <br />4 percent by volume for before-wet-runs (figs. 5B and 6B). Standard devi- <br />ation of after-run moisture contents ranged from about 2 to 5 percent by <br />volume. Spatial variability in after-run moisture content increases rapidly <br />with depth, especially for dry antecedent conditions, and indicates a highly <br />irregular wetting front and high variability in cumulative infiltration from <br />point to point. Moisture storage in the 0- to 20-in soil profile before and <br />after the August 3, 1981, run (fig. 5A) is shown in table 3. The data only <br /> <br />Table 3.--Mo-iA.twLe. 6:tolUlge .(.yt .the. 0- :to 20-blc.h M-U plto6-Ue <br />be.nOlLe. a.nd a.6.teJt 6.i.rnu1..a.t0lt Ir.uYl 06 Augu.6t 3, J 9 8 J, plot J <br />[Results in inches] <br /> <br />Hole <br /> <br />Before <br /> <br />After <br /> <br />1/ <br />Change- <br /> <br />1 1.44 3.72 2.28 <br />2 1.52 2.60 1.08 <br />3 1.60 2.70 1.10 <br />4 1.41 1. 74 .33 <br />5 1.35 3.33 1.98 <br />6 1.51 2.97 1.46 <br /> Mean 1.47 2.84 1.37 <br /> Standard .09 .69 .70 <br /> deviation. <br /> l/Values are only approximate; see text. <br /> <br />indicate an approximate change in moisture storage, because augering is a <br />destructive sampling technique and cannot be repeated at the same location. <br />After-run samples were located within about 8 to 10 in of the before-run <br />sample location on the same contour. The data shown in table 3 indicate <br />a large variation in point-to-point infiltration; this large variation in <br />infiltration reflects the large variation in depth of penetration, rather <br />than large differences in wet-up moisture content. <br /> <br />After-run moisture content of surface soils of 'about 45 to 50 percent <br />of saturation are lower than values normally reported or accepted as approp- <br />riate for ponded infiltration into homogeneous soils in the absence of a <br />surface crust. Rapid drainage and redistribution of soil water, occurring <br />before samples could be taken, may be a factor in explaining the low moisture <br />contents; however, a crusting phenomenon may exist. In addition, the soils <br /> <br />22 <br />