Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 27, 2007
Publication Date: March 28, 2007
Citation: Corwin, D.L. 2007. Mapping, Monitoring, and Assessment of Soil Salinity at Field Scales. 2007 Salinity/Drainage Conference held March 28, 2007. Technical Abstract: In the past, spatial and temporal variability has made it difficult to measure, map, and monitor soil salinity at field scales. Large numbers of soil samples were needed both across the landscape and within the soil profile to map field-scale salinity, making the task too labor and cost intensive to be practical. Past research at the U.S. Salinity Laboratory has developed the instrumental tools and techniques, which have been integrated into system, to assess salinity at field scales and larger. The integrated system uses geospatial measurements of apparent soil electrical conductivity (ECa) as a means of directing soil sampling to minimize the number of soil samples needed to characterize spatially within-field salinity distribution, requiring as few as 8-12 locations to characterize within-field distributions of salinity. Equipment, software, and protocols are presented to map salinity in three dimensions. To demonstrate the utility of the approach, two applications are discussed: (i) mapping and monitoring spatio-temporal changes in salinity resulting from drainage water reuse and (ii) delineating site-specific management units to manage salinity for precision agriculture application. Currently, efforts are in progress to couple ECa-directed soil sampling, satellite imagery (MODIS), and NRCS GIS databases and to evaluate their ability to assess salinity at a regional scale, i.e., the entire Red River Valley (5,000,000 ac) of ND and MN. At present, the ECa-directed soil sampling approach for mapping, monitoring, and assessing salinity at field scales and larger spatial extents is the most practical and reliable approach.