How to plot results of soil horizon analysis horizontally?

Question

I have measured soil organic matter (SOM) content for different soil horizons (i.e. different soil layers). Now I would like to plot the SOM content for the different horizons in a horizontal way, for each soil profile (i.e. each spot where I dug a hole and took soil samples) individually. I'll just add a sketch to describe what kind of plot I'd like to have:

I'd like to have the bars representing the SOM content, and want their left and right border to represent the top and bottom end of each horizon, respectively - so the bar width would illustrate the thickness of each horizon (soil layer). Basically, this would give me a soil profile, just in a horizontal instead of a vertical order.

Now, as I have a total of 24 profiles with different soil types, I would probably use facet_grid or facet_wrap to plot each soil profile individually. However, I'm quite lost how to do the rest. Does anybody have suggestions? I got stuck after a first trial with a subset of my data:

barplot <- ggplot(TSM1, aes(x=top, y=SOM)) + geom_col()

I'll attach a data subset with data of 3 soil profiles here below:

    structure(list(tmp_id = 1:19, Profil = structure(c(10L, 10L, 
10L, 10L, 10L, 10L, 10L, 11L, 11L, 11L, 11L, 11L, 12L, 12L, 12L, 
12L, 12L, 12L, 12L), .Label = c("TNH1", "TNH2", "TNH3", "TNM1", 
"TNM2", "TNM3", "TSH1", "TSH2", "TSH3", "TSM1", "TSM2", "TSM3", 
"VNH1", "VNH2", "VNH3", "VNM1", "VNM2", "VNM3", "VSH1", "VSH2", 
"VSH3", "VSM1", "VSM2", "VSM3"), class = "factor"), site = structure(c(4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L), .Label = c("TNH", "TNM", "TSH", "TSM", "VNH", "VNM", 
"VSH", "VSM"), class = "factor"), elevation = structure(c(2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L), .Label = c("high", "mid"), class = "factor"), exposition = structure(c(2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L), .Label = c("north", "south"), class = "factor"), region = structure(c(1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L), .Label = c("ticino", "valais"), class = "factor"), Horizon = structure(c(42L, 
24L, 18L, 19L, 41L, 11L, 12L, 42L, 24L, 26L, 40L, 20L, 42L, 24L, 
18L, 19L, 44L, 1L, 17L), .Label = c("[IICsi]", "[nOL-vOL]", "[nOL]-vOL-S*", 
"[OF]", "[vOL-S*]", "A", "A-S1", "Acaho", "bryOF", "bryOH", "Csi", 
"Dsi", "g", "IIA", "IICsi", "IICsi&Dsi", "IIDsi", "ligOF", "ligOH", 
"Msi", "nOL-[vOL]-[S*]", "nOL-vOL", "nOL-vOL-[S*]", "OF", "OF-[OH]", 
"OH", "rhiA", "rhiA-S1", "rhiA1", "rhiA2", "rhiAho", "rhiAho-Csi", 
"rhiOF", "rhiOH", "S", "S1", "S2", "Sal", "Sal-Csi", "sgA", "sgAho", 
"vOL", "Xp", "Xp&[Aho]", "Xpcaho", "Xpcaho "), class = "factor"), 
    Horizon_order = c(0L, 0L, 0L, 0L, 1L, 2L, 3L, 0L, 0L, 0L, 
    1L, 2L, 0L, 0L, 0L, 0L, 1L, 2L, 3L), Horizon_type = structure(c(1L, 
    2L, 4L, 8L, 10L, 15L, 16L, 1L, 2L, 6L, 10L, 16L, 1L, 2L, 
    4L, 8L, 12L, 15L, 16L), .Label = c("H1", "H2", "H2a", "H2b", 
    "H2c", "H3", "H3a", "H3b", "H3c", "H4", "H4a", "H4b", "H5", 
    "H5b", "H6", "H7", "H7b", "H8"), class = "factor"), Sol_ref = structure(c(7L, 
    7L, 7L, 7L, 7L, 7L, 7L, 13L, 13L, 13L, 13L, 13L, 8L, 8L, 
    8L, 8L, 8L, 8L, 8L), .Label = c("ALOCRISOL TYPIQUE", "BRUNISOL DYSTRIQUE", 
    "BRUNISOL DYSTRIQUE à horizon rédoxique de profondeur", "COLLUVIOSOL", 
    "COLLUVIOSOL brunifié", "COLLUVIOSOL leptique", "ORGANOSOL", 
    "ORGANOSOL (holorganique)", "ORGANOSOL holorganique", "ORGANOSOL INSATURE à COLLUVIOSOL", 
    "ORGANOSOL SATURE à COLLUVIOSOL", "PEYROSOL pierrique humifère calcaire", 
    "REGOSOL d'apport"), class = "factor"), Type_sol = structure(c(4L, 
    4L, 4L, 4L, 4L, 4L, 4L, 6L, 6L, 6L, 6L, 6L, 4L, 4L, 4L, 4L, 
    4L, 4L, 4L), .Label = c("ALOCRISOL", "BRUNISOL", "COLLUVIOSOL", 
    "ORGANOSOL", "PEYROSOL", "REGOSOL"), class = "factor"), Type_humus = structure(c(3L, 
    3L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 
    3L, 3L, 3L), .Label = c("Dysmull", "Humimor", "ligno", "ligno Humimor", 
    "ligno/bryo", "Mésomull", "Oligomull", "rhizo Dysmoder", 
    "rhizo Eumoder", "rhizo Hémimoder", "rhizo Mésomull", "rhizo Oligomull"
    ), class = "factor"), N_deca = c(NA_real_, NA_real_, NA_real_, 
    NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, 
    NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, 
    NA_real_, NA_real_, NA_real_, NA_real_), C_deca = c(NA_real_, 
    NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, 
    NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, 
    NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_
    ), N = c(NA, NA, NA, NA, 0.33, 0.16, NA, NA, NA, NA, 0.25, 
    0.09, NA, NA, NA, NA, 0.56, 0.21, NA), C = c(NA, NA, NA, 
    NA, 9.95, 3.16, NA, NA, NA, NA, 6.29, 2.23, NA, NA, NA, NA, 
    11.65, 4.93, NA), C.N = c(NA, NA, NA, NA, 30.56, 20.26, NA, 
    NA, NA, NA, 24.87, 23.97, NA, NA, NA, NA, 20.82, 23.43, NA
    ), HR = c(NA, NA, NA, NA, 2.6, 1.79, NA, NA, NA, NA, 2.58, 
    1.91, NA, NA, NA, NA, 4.28, 4.42, NA), PAF = c(NA, NA, NA, 
    NA, 16.97, 6.71, NA, NA, NA, NA, 13.34, 5.44, NA, NA, NA, 
    NA, 22.11, 10.06, NA), SOM = c(NA, NA, NA, NA, 8.49, 3.35, 
    NA, NA, NA, NA, 6.67, 2.72, NA, NA, NA, NA, 11.06, 5.03, 
    NA), Argile = c(NA, NA, NA, NA, 3.78, 3.75, NA, NA, NA, NA, 
    3.05, 5.33, NA, NA, NA, NA, 3.78, 7.08, NA), Limon = c(NA, 
    NA, NA, NA, 32.76, 27.26, NA, NA, NA, NA, 28.44, 40.9, NA, 
    NA, NA, NA, 33.2, 47.65, NA), Sable = c(NA, NA, NA, NA, 63.47, 
    68.99, NA, NA, NA, NA, 68.51, 53.77, NA, NA, NA, NA, 63.02, 
    45.26, NA), pH = c(NA, NA, NA, NA, 3.76, 4.11, NA, NA, NA, 
    NA, 4.29, 4.94, NA, NA, NA, NA, 3.94, 4.8, NA), CEC_tot = c(NA, 
    NA, NA, NA, 8.43, 4.21, NA, NA, NA, NA, 7.83, 1.24, NA, NA, 
    NA, NA, 11.87, 6.1, NA), CO3 = c(NA, NA, NA, NA, 0.8, 0.89, 
    NA, NA, NA, NA, 0.88, 0.96, NA, NA, NA, NA, 0.82, 0.91, NA
    ), K = c(NA, NA, NA, NA, 0.02, 0.02, NA, NA, NA, NA, 0.02, 
    0.02, NA, NA, NA, NA, 0.03, 0.02, NA), Mg = c(NA, NA, NA, 
    NA, 0, 0, NA, NA, NA, NA, 0.01, 0.01, NA, NA, NA, NA, 0.01, 
    0.01, NA), Ca = c(NA, NA, NA, NA, 0, 0, NA, NA, NA, NA, 0, 
    0, NA, NA, NA, NA, 0, 0, NA), Na = c(NA, NA, NA, NA, 0.01, 
    0.01, NA, NA, NA, NA, 0.02, 0.02, NA, NA, NA, NA, 0.02, 0.02, 
    NA), CEC.T = c(NA, NA, NA, NA, 4.84, 1.14, NA, NA, NA, NA, 
    21.51, 29.74, NA, NA, NA, NA, 19.09, 19.55, NA), Munsell = structure(c(NA, 
    NA, 24L, 22L, 8L, 11L, NA, NA, NA, 5L, 9L, 14L, NA, NA, NA, 
    22L, 9L, 11L, NA), .Label = c("10YR", "10YR2/1", "10YR2/2", 
    "10YR2/2 foncé", "10YR3/3", "10YR3/4", "10YR3/6", "10YR4/2", 
    "10YR4/3", "10YR4/4", "10YR4/6", "10YR5/4", "10YR5/6", "10YR5/8", 
    "2.5Y3/2", "2.5Y4/1", "2.5YR4/1", "5YR2.5/1", "5YR3/3", "7.5YR", 
    "7.5YR2.5/2", "7.5YR2.5/3", "7.5YR3/1", "7.5YR3/3", "7.5YR4/2", 
    "7.5YR5/6"), class = "factor"), hue = structure(c(NA, NA, 
    5L, 5L, 1L, 1L, NA, NA, NA, 1L, 1L, 1L, NA, NA, NA, 5L, 1L, 
    1L, NA), .Label = c("10YR", "2.5Y", "2.5YR", "5YR", "7.5YR"
    ), class = "factor"), value = c(NA, NA, 3L, 3L, 4L, 4L, NA, 
    NA, NA, 3L, 4L, 5L, NA, NA, NA, 3L, 4L, 4L, NA), chroma = c(NA, 
    NA, 3L, 3L, 2L, 6L, NA, NA, NA, 3L, 3L, 8L, NA, NA, NA, 3L, 
    3L, 6L, NA), top = c(1.25, 0, 1, 5, 19, 23, 33, 2.5, 0, 3.5, 
    6, 8.5, 2.5, 0, 2, 6, 13, 31, 38.5), bottom = c(0, 1, 5, 
    19, 23, 33, NA, 0, 3.5, 6, 8.5, NA, 0, 2, 6, 13, 31, 38.5, 
    NA), Classe = structure(c(3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
    3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("Caricetea curvulae", 
    "Fraxino-Fagetea", "Vaccinio-Picetea"), class = "factor"), 
    Alliance = structure(c(3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
    3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("Abieti-Piceion", 
    "Caricion curvulae", "Dicrano-Pinion", "Fagion", "Nardion strictae", 
    "Rhododendro-Vaccinion", "Vaccinio-Piceion"), class = "factor"), 
    Association = structure(c(3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
    3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("Abieti-Fagetum", 
    "Adenostylo-Abietetum", "Calluno-Pinetum", "Carici curvulae-Nardetum", 
    "Geo montani-Nardetum", "Homogyno-Piceetum", "Hypochoerido-Nardetum", 
    "Larici-Piceetum", "Rhododendro ferruginei-Vaccinietum"), class = "factor"), 
    Localite = structure(c(5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 
    5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L), .Label = c("Campo_tencia", 
    "Dalpe", "La Forcle", "La Tourche", "Osco", "Predelp", "Valassier", 
    "Valerette"), class = "factor"), Canton = structure(c(1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L), .Label = c("Tessin", "Valais-Vaud"), class = "factor"), 
    Exposition = structure(c(2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("North", 
    "South"), class = "factor"), Altitude = structure(c(2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
    2L, 2L), .Label = c("High", "Mid"), class = "factor"), Profil.1 = c(1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 
    3L, 3L, 3L), Latitude = c(702521L, 702521L, 702521L, 702521L, 
    702521L, 702521L, 702521L, 702762L, 702762L, 702762L, 702762L, 
    702762L, 702929L, 702929L, 702929L, 702929L, 702929L, 702929L, 
    702929L), Longitude = c(150999L, 150999L, 150999L, 150999L, 
    150999L, 150999L, 150999L, 150835L, 150835L, 150835L, 150835L, 
    150835L, 150630L, 150630L, 150630L, 150630L, 150630L, 150630L, 
    150630L), Slope = c(20L, 20L, 20L, 20L, 20L, 20L, 20L, 35L, 
    35L, 35L, 35L, 35L, 20L, 20L, 20L, 20L, 20L, 20L, 20L)), row.names = c(NA, 
19L), class = "data.frame")

Relevant variables/factors:

Profil = unique name/identifier for each profile
SOM = soil organic matter (in %)
top = top margin of each soil horizon (soil layer)
bottom = bottom margin of each soil horizon

veeeeery related https://stackoverflow.com/questions/20688376/how-to-make-variable-bar-widths-in-ggplot2-not-overlap-or-gap and https://stackoverflow.com/questions/66197720/overlapping-barplot-histogram-with-variable-widths?noredirect=1&lq=1 and https://stackoverflow.com/questions/11345943/bar-graph-in-ggplot2-with-width-as-a-variable-and-even-spacing-between-bars?noredirect=1&lq=1 — tjebo, Jan 31 '22 at 18:03
Thanks for the post links - I'm still at the very beginning of learning R language, and sometimes I struggle to find accurate terms/descriptions for my problems, being a non-native speaker and not very trained in using rather technical terms... I'll try to use the search function in more accurate ways :) — paki, Feb 01 '22 at 08:47
paki - this was a good first question. I'm voting to close this as a duplicate, don't worry if the question has been asked before, it helps making other answers more visible. — tjebo, Feb 01 '22 at 08:59
Does this answer your question? [Overlapping barplot/histogram with variable widths](https://stackoverflow.com/questions/66197720/overlapping-barplot-histogram-with-variable-widths) — tjebo, Feb 01 '22 at 09:00

score 1 · Answer 1 · answered Jan 31 '22 at 17:24

1

It seems to me that what you're describing isn't a typical bar plot, but what you describe can be done with geom_rect().

library(ggplot2)

# df <- structure(...) # omitted for brevity

ggplot(df, aes(x = top, y = SOM)) +
  geom_rect(
    aes(xmin = bottom, xmax = top, ymin = 0, ymax = SOM)
  ) +
  facet_wrap(~ Profil)
#> Warning: Removed 14 rows containing missing values (geom_rect).

answered Jan 31 '22 at 17:24

teunbrand

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Thanks a lot! I didn't know this geom type, now it seems like a "silly" question to me, seeing this easy way...Still have to get more into all the terms of R language. – paki Feb 01 '22 at 08:45
I have one additional question. I'd like to add also the other horizons so I can see the full sequence of each soil profile, even though I do not have SOM results for the remaining horizons. So I made a subset where I only have the rows with SOM = NA, I changed the "NA" to have a constant value of 2.5 for all ( I would color it differently so one can distinguish between measured and not-measured horizons), and tried to add those by just using two geom_rect. However, this does not work. Do you have an idea how to make it function? – paki Feb 01 '22 at 10:36

How to plot results of soil horizon analysis horizontally?

1 Answers1