ARS | Publication request: How Well Does Zone Sampling Based On Soil Electrical Conductivity Maps Represent Soil Variability

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: July 7, 2009
Publication Date: November 15, 2009
Citation: Shaner, D.L. 2009. How Well Does Zone Sampling Based On Soil Electrical Conductivity Maps Represent Soil Variability. American Society of Agronomy Meetings.

Technical Abstract: How Well Does Zone Sampling Based On Soil Electrical Conductivity Maps Represent Soil Variability. Dale L. Shaner A study was conducted determined if ECa-directed zone sampling could predict soil texture and soil organic matter (SOM) patterns of samples taken by a more intensive grid sample method. Each field was divided into three ECa zones and soil texture and organic matter content in the top 30 cm of soil were measured. There was a significant difference in the soil texture and SOM in both fields between ECa Zone 1 and Zone 3. Logistic regression showed that in both fields, approximately 80% of the grid sample sites in ECa Zone 1 were correctly predicted. Only 50% of the grid sample sites in ECa Zone 3 were correctly predicted as Zone 3 in one field whereas 77% of the grid sites in ECa Zone 3 were correctly predicted in the other field. However, approximately 80% of the samples in the grid sites > 10 m from the zone boundaries were classified correctly as compared to the samples that were <10 m from the boundary in which only 50-54% were classified correctly . These results support the utilization of ECa-directed zone sampling as an alternative to grid soil sampling if the transition zones are avoided.