agridat (version 1.8.1)

baker.barley.uniformity: Ten years of barley uniformity trials on same ground

Description

Ten years of barley uniformity trials on same ground

source

Baker, GA and Huberty, MR and Veihmeyer, FJ. (1952) A uniformity trial on unirrigated barley of ten years' duration. Agronomy Journal, 44, 267-270.

Details

Ten years of uniformity trials were sown on the same ground.

Examples

dat <- baker.barley.uniformity

desplot(yield~col*row|year, data=dat, main="Heatmaps by year")
dat2 <- aggregate(yield ~ row*col, data=dat, FUN=mean, na.rm=TRUE)
asp <- (161*3+30)/827 # True aspect ratio
desplot(yield~col*row, data=dat2, main="Avg yield over 10 years", aspect=asp)
# Note lower yield in upper right, slanting to left a bit due to sandy soil.

# 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")

# Baker table 4, correlation of plots across years
require(reshape2)
mat <- acast(dat, row+col~year)
round(cor(mat, use='pair'),2)