Look up siblings and cousins for a given soil series from the current fiscal year SSURGO snapshot via SoilWeb.

The siblings of any given soil series are defined as those soil components (major and minor) that share a parent map unit with the named series (as a major component). Component names are filtered using a snapshot of the Soil Classification database to ensure that only valid soil series names are included. Cousins are siblings of siblings. Data are sourced from SoilWeb which maintains a copy of the current SSURGO snapshot. Visualizations of soil "siblings"-related concepts can be found in the "Sibling Summary" tab of Soil Data Explorer app: https://casoilresource.lawr.ucdavis.edu/sde/.

Additional resources:

siblings(s, only.major = FALSE, component.data = FALSE, cousins = FALSE)



character vector, the name of a single soil series, case-insensitive.


logical, should only return siblings that are major components


logical, should component data for siblings (and optionally cousins) be returned?


logical, should siblings-of-siblings (cousins) be returned?


A list containing:

  • sib: data.frame containing siblings, major component flag, and number of co-occurrences

  • sib.data: data.frame containing sibling component data (only when component.data = TRUE)

  • cousins: data.frame containing cousins, major component flag, and number of co-occurrences (only when cousins = TRUE)

  • cousin.data: data.frame containing cousin component data (only when cousins = TRUE, component.data = TRUE)


O'Geen, A., Walkinshaw, M. and Beaudette, D. (2017), SoilWeb: A Multifaceted Interface to Soil Survey Information. Soil Science Society of America Journal, 81: 853-862. doi: 10.2136/sssaj2016.11.0386n

See also

OSDquery, siblings, fetchOSD


D.E. Beaudette


# \donttest{ if(requireNamespace("curl") & curl::has_internet()) { # basic usage x <- siblings('zook') x$sib # restrict to siblings that are major components # e.g. the most likely siblings x <- siblings('zook', only.major = TRUE) x$sib }
#> series sibling majcompflag n #> 1 zook Olmitz TRUE 17 #> 2 zook Vigar TRUE 12 #> 3 zook Ely TRUE 10 #> 4 zook Vesser TRUE 10 #> 5 zook Excello TRUE 9 #> 6 zook Colo TRUE 8 #> 7 zook Nodaway TRUE 5 #> 8 zook Mt. Sterling TRUE 3 #> 9 zook Zoe TRUE 3 #> 10 zook Kezan TRUE 2 #> 11 zook Clamo TRUE 2 #> 12 zook Humeston TRUE 1 #> 13 zook Klum TRUE 1 #> 14 zook Quiver TRUE 1
# }