baker.barley.uniformity.Rd
Uniformity trials of barley at Davis, California, 1925-1935, 10 years on same ground.
A data frame with 570 observations on the following 4 variables.
row
row
col
column
year
year
yield
yield, pounds/acre
Ten years of uniformity trials were sown on the same ground. Baker (1952) shows a map of the field, which gravel subsoil extended from the upper right corner diagonally lower-left. This results in lower yields as seen on the 10-year average map.
Field width: 19 plots = 827 ft
Field length: 3 plots * 161 ft + 2 alleys * 15 feet = 513 ft
Baker, GA and Huberty, MR and Veihmeyer, FJ. (1952) A uniformity trial on unirrigated barley of ten years' duration. Agronomy Journal, 44, 267-270. https://doi.org/10.2134/agronj1952.00021962004400050011x
# \dontrun{ library(agridat) data(baker.barley.uniformity) dat <- baker.barley.uniformity # Ten-year average dat2 <- aggregate(yield ~ row*col, data=dat, FUN=mean, na.rm=TRUE) libs(desplot) desplot(dat, yield~col*row|year, aspect = 513/827, # true aspect main="baker.barley.uniformity - heatmaps by year")desplot(dat2, yield~col*row, aspect = 513/827, # true aspect main="baker.barley.uniformity - heatmap of 10-year average")# Note low yield in upper right, slanting to left a bit due to sandy soil # as shown in Baker figure 1. # Baker fig 2, stdev vs mean dat3 <- aggregate(yield ~ row*col, data=dat, FUN=sd, na.rm=TRUE) plot(dat2$yield, dat3$yield, xlab="Mean yield", ylab="Std Dev yield", main="baker.barley.uniformity")# Baker table 4, correlation of plots across years # libs(reshape2) # mat <- acast(dat, row+col~year) # round(cor(mat, use='pair'),2) # }