agridat (version 1.8.1)

garber.multi.uniformity: Uniformity trials of oat hay and wheat

Description

Uniformity trials of oat straw and wheat

source

Garber, RJ and Mcllvaine, TC and Hoover, MM. 1926. A study of soil heterogeneity in experiment plots. Jour. Agr. Res, 33, 255-268. http://naldc.nal.usda.gov/download/IND43967148/PDF.

Details

In 1923 the field was planted to oats and harvested as hay. In 1924 the field was planted to wheat and harvested for grain. Garber: "Plots 211 to 214, and 261 to 264, [note, these are rows 11-14, columns 5-6] inclusive, were eliminated from this study because of the fact that a few years ago a straw stack had stood on or in the vicinity...which undoubtedly accounts for the relatively high yields on plots 261 to 264, inclusive." Note: The source document contained mean-subtracted yields. The oat yield in row 22, column 5 was given as +59.7. This is obviously incorrect, since the negative yields all end in '.7' and positive yields all ended in '.3'. We used -59.7 as the centered yield value and added the mean of 1883.7 to all centered yields to obtain absolute yields.

Examples

dat <- garber.multi.uniformity

desplot(oats ~ col*row, data=dat, flip=TRUE, tick=TRUE,
        main="garber.multi.uniformity oats")
desplot(wheat ~ col*row, data=dat, flip=TRUE, tick=TRUE,
        main="garber.multi.uniformity wheat")
with(dat, cor(oats, wheat)) # = .37 matches Garber