Mineral Soil Element Data 1992 and 2006

for the Walker Branch Throughfall Displacement Experiment (TDE)

1.0 DOCUMENT INFORMATION
1.1 Document Title: TDE mineral soil data
1.2 Revision Date:  6 June 2008
1.3 Document Summary:  Pre- and Post-treatment mineral element data for TDE soils
1.4 Sponsor: Office of Biological and Environmental Research, U. S. DOE

 2.0 INVESTIGATOR
2.1 Investigator and data set contact:

Dale W. Johnson (dwj@cabnr.urn.edu)
Natural Resources and Environmental Science
University of Nevada, Reno
Reno, NV 89557

or

Donald E. Todd Jr. (todddejr@ornl.gov) or Paul J. Hanson (hansonpj@ornl.gov)
Environmental Sciences Division
Oak Ridge National Laboratory
P.O. Box 2008, Building 1062
Oak Ridge, TN 37831-6422
2.2 Title Of Investigation:
Walker Branch Throughfall Displacement Experiment (TDE)

 3.0 DATA SUMMARY

Mineral soil element data for all three treatment areas of the TDE site before (1992) and after 12 years of sustained chronic precipitation manipulations (2006) initiated in July of 1993.

 4.0 PROCEDURES 

Mineral soils were sampled in January–February 1992 with a standard 6.6 cm diameter bucket auger and again in January–February 2006 with a gasoline powered 10 cm diameter diamond bit coring tool. At both times, sampling was in 15cm increments to a depth of 60 cm. Soil samples were oven dried at 70 °C and passed through a 2-mm sieve. In order to control for laboratory bias, soils from the 1992 sampling were archived and analyzed along with the 2006 soils. The 2mm fraction was analyzed for exchangeable Ca2+, Mg2+, K+, Na2+ (10 g soil in 50mL 1N ammonium acetate), bicarbonate-extractable P (2 g soil in 50mL 0.05M NaHCO3), and Bray-extractable P (2 g soil in 0.5M HCl plus 1M NH4+). Extracts were analyzed using a Jarrell Ash ion coupled plasma spectrophotometer (Thermo Jarrell Ash Corp., Franklin, MA, USA) at A&L Western Agricultural Laboratories (Modesto, CA, USA). Total C and N were analyzed using a dry combustion C and N analyzer (LECO, St Joseph, MI, USA) at the Oklahoma State University Soil, Water, and Forage Analytical Laboratory (Stillwater, OK, USA). Soil element contents were calculated from bulk density and percent gravel from nearby plots by horizon and summed up to obtain values for each 15cm layer of the 0–60cm profile.

 5.0 OBSERVATION NOTES
    None

6.0 DATA ORGANIZATION

Data are provided in comma delimeted csv files where the first line includes the variable names and subsequent lines include the following data by year.

6.1 Variable, Definition, and Units (as appropriate)

15 =  0 to 15 cm
30 = 15 to 30 cm
45 = 30 to 45 cm
60 = 45 to 60 cm
6.2 Number of Records: 10458 individual element measurements.

6.3 Missing data: Yes, represented by blank or empy cells between commas.

6.4 Related Data Sets:  Data sets on organic layer elements over time for the TDE are also archived. 

7.0 KNOWN ERRORS AND QUALITY ASSESSMENT

No known errors other than missing samples. 

8.0 NOTES

8.1 Limitations of the data:   None.

8.2 Known Problems With The Data:  None.

8.3 Usage Guidance:   None.

9.0 REFERENCES:

Johnson DW, Todd DE Jr, Hanson PJ (2008) The effects of throughfall manipulation on soil nutrient status: results of 12 years of sustained wet and dry treatments. Global Change Biology 14:1661-1675.

Fröberg M, Hanson PJ, Todd DE, Johnson DW (2008) Evaluation of effects of sustained decadal precipitation manipulations on soil carbon stocks.  Biogeochemistry (in press).

10.0 DATA LISTING

Click on the following text to view the column delminited data for the listed year.
Once open the files can exported as text files with the 'Save As' command.

mineralsoil.csv