RCB experiment of oats, straw and grain, 9 fertilizer treatments

Usage

data("rothamsted.oats")

Format

A data frame with 96 observations on the following 6 variables.

block: block
trt: fertilizer treatment with 9 levels
grain: grain, pounds per plot
straw: straw, pounds per plot
row: row
col: column

Details

Oats (Grey Winter) grown at Rothamsted, Long Hoos field 1926.

Values of grain and straw are actual weights in pounds. Each plot was 1/40 acre. The plot dimensions are not given, but the Rothamsted report shows the field being square.

The treatment codes are: OA,OB,OC,OD = No top dressing. E/L = Early/late application. S/M = Sulphate or muriate of ammonia. 1/2 = Single or double dressing.

Source

Rothamsted Report 1925-26, p. 146. https://www.era.rothamsted.ac.uk/eradoc/article/ResReport1925-26-138-155 Electronic version of data supplied by David Clifford.

References

McCullagh, P. and Clifford, D., (2006). Evidence for conformal invariance of crop yields, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Science, 462, 2119–2143. https://doi.org/10.1098/rspa.2006.1667

Examples

if (FALSE) { # \dontrun{
  
  library(agridat)
  data(rothamsted.oats)
  dat <- rothamsted.oats

  
  libs(desplot)
  desplot(dat, grain~col*row,
          out1=block, text=trt, cex=1, shorten=FALSE,
          aspect=1,
          main="rothamsted.oats")
  desplot(dat, straw~col*row,
          out1=block, text=trt, cex=1, shorten=FALSE,
          aspect=1,
          main="rothamsted.oats")

  
  libs(lattice)
  xyplot(grain~straw, dat,
         main="rothamsted.oats") # traits are correlated


  if(0){
    # compare to summary at bottom of page 146, first 3 columns
    libs(dplyr)
    dat = mutate(dat,
                 nfert=trt, # number of fertilizer applications
                 nfert=dplyr::recode(nfert,
                                     "oa"="None", "ob"="None",
                                     "oc"="None", "od"="None",
                                     "1se"="Single", "1sl"="Single",
                                     "1me"="Single", "1ml"="Single",
                                     "2se"="Double", "2sl"="Double",
                                     "2me"="Double", "2ml"="Double"))
    # English ton = 2240 pounds, cwt = 112 pounds
    # multiply by 40 to get pounds/acre
    # divide by: 112 to get hundredweight/acre, 42 to get bushels/acre
    # Avoid pipe operator in Rd examples!
    dat <- group_by(dat, nfert)
    dat <- summarize(dat, straw=mean(straw), grain=mean(grain))
    dat <- mutate(dat, straw= straw * 40/112, grain = grain * 40/42)
    ## # A tibble: 3 x 3
    ##   nfert  straw grain
    ##   <fct>  <dbl> <dbl>
    ## 1 Single  50.3  78.9
    ## 2 Double  53.7  77.7
    ## 3 None    44.1  75.4
  }

} # }