3000
22500 - //
A m
0' 2000 - / A *
> 1500- A /*/ *
_ o-o / -/
1000-
o 500 ~ 0
0 2 4 6 8 10 12 14
Change in Soil Moisture Content (%)
Figure 3. Relationship between volume emitted and the change in soil moisture at 3 distances from
the emitter.
RESULTS
Statistical analysis of the data resulted in no correlation between the TDR values and the
volumetric measurements. As seen in figure 3, there is a good correlation between the volume
applied and the change in soil moisture content (average r2 of 0.872). However, variability in the
data prevented prediction of a DUIq equivalent to that calculated from volumetric data. Also,
the regression has less resolution at the high and low ends of the spectrum.
Distribution uniformity based on soil moisture data and volumetric data was calculated according
to equation 1 and graphed for each time and distance combination for a total of 18 graphs. According
to figure 4, which shows all of these graphs, there is no consistent relationship between the
DUIq calculated from soil moisture content and the DUIq based on volumetric data. Although
the volumetric DUIq varied between 0.42 and 0.87, there was no predictable variation from the
DUIq calculated from TDR data.