Comparison of Soil Water Content Distributions Between Irrigated and Non-Irrigated Cropland During the BEAREX08 Experiment.

The Bushland Evapotranspiration and Agricultural Remote Sensing Experiment (BEAREX08) was conducted near Bushland, TX during the summer of 2008 in a pair of cotton fields, one irrigated and the other dryland.  A large number of evaporative flux and meteorological sensors were installed within the study domain (400 m by 400 m) to fully characterize each field.  To complement this study, two soil moisture sensor networks were installed, each containing 21 sensors, to monitor the near surface soil water content throughout the summer and characterize the distributions for the irrigation/dryland regimes.  Coupled with these networks, a series of intensive observational periods were conducted in coordination with aircraft overflights and flux monitoring activities to evaluate the accuracy of the networks and determine the scalability of the point measurements to the larger field scale.  The networks performed reliably with good accuracy to the larger scale, though there was considerable calibration for the dielectric sensors used for the low and high density sampling. Time series and variance analysis along with wavelet and semivariogram analysis revealed the small scale structure of soil moisture down to the 5 cm scale.