Get the stable version from CRAN:

install.packages('aqp', dep=TRUE)

Get the development version from Github, after installing the CRAN version + dependencies:

remotes::install_github("ncss-tech/aqp", dependencies=FALSE, upgrade=FALSE, build=FALSE)

http://ncss-tech.github.io/AQP/

library(aqp)
data(sp4)
depths(sp4) <- id ~ top + bottom

par(mar=c(0,0,4,0))
plot(sp4, color='clay')
plot(sp4, color='CF')

Dylan Beaudette, Pierre Roudier and Andrew Brown (2021). aqp: Algorithms for Quantitative Pedology. R package version 1.29. https://CRAN.R-project.org/package=aqp

D.E. Beaudette, P. Roudier, A.T. O'Geen, Algorithms for quantitative pedology: A toolkit for soil scientists, Computers & Geosciences, Volume 52, March 2013, Pages 258-268, ISSN 0098-3004, http://dx.doi.org/10.1016/j.cageo.2012.10.020.

• soilDB
• sharpshootR

• https://www.pnas.org/content/115/26/6751
• as found by Scopus
• as found by Google Scholar
• http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2179-80872019000100121