Washita '92 Gravimetric Soil Moisture

The data report contained the field average values of soil moisture. This section has the raw data. A gravimetric soil moisture sample was collected using a specially designed scoop that extracts a 5 cm cube. This sample is then placed in a metal can and sealed. The can number is then recorded on a schematic map of the site showing its approximate location. These gravimetric samples were then weighed at the ARS lab to obtain a wet weight. All samples were then dried for 24 hours and weighed again to obtain a dry weight. The gravimetric soil moisture was then computed by dividing the difference between the wet and dry weight by the dry weight less the can tare.

The geolocation of these samples within a field is quite difficult. The only reference material are field notebooks (kept at the USDA ARS Hydrology and Remote Sensing Lab). These notebooks usually have a schematic showing the can number sites in a field. The nominal spacing is usually stated or can be inferred, however, some notes are very poor and incomplete.