A single column name from tables: lab_combine_nasis_ncss, lab_webmap, lab_site, lab_pedon or lab_area. Common choices include pedlabsampnum (Laboratory Pedon ID), upedonid (User Pedon ID), corr_name ('Correlated' Taxon Name), samp_name ('Sampled As' Taxon Name), or area_code (area symbol for specified lab_area records, see area_type).
Details
-
If the chunk.size parameter is set too large and the Soil Data Access request fails, the algorithm will re-try the query with a smaller (halved) chunk.size argument. This will be attempted up to 3 times before returning NULL
-
Currently the lab_area tables are joined only for the "Soil Survey Area" related records.
+
You can download SQLite or GeoPackage snapshots here: https://ncsslabdatamart.sc.egov.usda.gov/database_download.aspx. Specify the dsn argument to use a local copy of the lab data rather than Soil Data Access web service.
+
Lab Data Mart model diagram: https://jneme910.github.io/Lab_Data_Mart_Documentation/Documents/SDA_KSSL_Data_model.html
+If the chunk.size parameter is set too large and the Soil Data Access request fails, the algorithm will re-try the query with a smaller (halved) chunk.size argument. This will be attempted up to 3 times before returning NULL
+
The default behavior joins the lab_area tables only for the "Soil Survey Area" related records. You can specify alternative area records for use in x, what or WHERE arguments by setting area_type to a different value.
When requesting data from "lab_major_and_trace_elements_and_oxides", "lab_mineralogy_glass_count", or "lab_xray_and_thermal" multiple preparation codes (prep_code) or size fractions (analyzed_size_frac) are possible. The default behavior of fetchLDM() is to attempt to return a topologically valid (minimal overlaps) SoilProfileCollection. This is achieved by setting prep_code="S" ("sieved") and analyzed_size_frac="<2 mm". You may specify alternate or additional preparation codes or fractions as needed, but note that this may cause "duplication" of some layers where measurements were made with different preparation or on fractionated samples
Examples
if (FALSE) { # \dontrun{
- # fetch by ssa_key
- res <- fetchLDM(8297, what = "ssa_key")
+
+ # fetch by Soil Survey Area area symbol (area_code using default "ssa" area_type)
+ res <- fetchLDM("CA630", what = "area_code")
+
+ # fetch by Major Land Resource area symbol (area_code using "mlra" area_type)
+ res <- fetchLDM("22A", what = "area_code", area_type = "mlra")
+
+ # fetch by multiple case-insensitive taxon name
+ # (correlated or sampled as Musick or Holland series)
+ res <- fetchLDM(WHERE = "(CASE WHEN corr_name IS NOT NULL
+ THEN LOWER(corr_name)
+ ELSE LOWER(samp_name)
+ END) IN ('musick', 'holland')")
- # physical properties correlated as taxonomic subgroup "Typic Argialbolls"
+ # physical properties of soils correlated as taxonomic subgroup "Typic Argialbolls"
res <- fetchLDM(x = "Typic Argialbolls",
what = "corr_taxsubgrp",
tables = "lab_physical_properties")
- # fetch by area_code (SSA only)
- res <- fetchLDM("CA630", what = "area_code")
} # }
diff --git a/reference/fetchNASIS.html b/reference/fetchNASIS.html
index f28d9d1c..50be8566 100644
--- a/reference/fetchNASIS.html
+++ b/reference/fetchNASIS.html
@@ -59,7 +59,7 @@