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

In kwstat/agridat: Agricultural Datasets

Uniformity trials of oat hay and wheat grain

Description

Uniformity trials of oat hay and wheat grain, at West Virginia Agricultural Experiment Station, 1923-1924, on the same land.

Format

A data frame with 270 observations on the following 4 variables.

row

row

col

column

oats

yield of oat hay, pounds per acre

wheat

yield of wheat grain, bu

Details

Each plot was 68 feet x 21 feet. After discarding a 3.5 foot border on all sides, the harvested area was 61 feet x 14 feet. The plots were laid out in doubles with a 14-foot roadway between the plots.

Note: The orientation of the plots (68x21) is an educated guess. If the orientation was 21x68, the field would be extremely narrow and long.

Field width: 6 plots * 68 feet + 14 ft/roadway * 2 = 436 feet

Field length: 45 plots * 21 feet/plot = 945 feet

Garber said: "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."

1923 results

In 1923 the field was planted to oats and harvested as hay.

The data for the oat hay was given in Table 5 as mean-subtracted yields in pounds per acre for each plot. 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 (p. 259) to all centered yields to obtain absolute yields.

1924 results

In 1924 the field was planted to winter wheat and harvested for grain.

The data for the wheat was given in bushels per acre, expressed as deviations from the mean yield (15.6 bu). We added the mean to all plot data.

Note, Garber et al (1926) and Garber et al (1931) describe uniformity trials from the same field, but the experimental plot numbers in the two papers are different, indicating different parts of the field.

Source

Garber, R.J. and Mcllvaine, T.C. and Hoover, M.M. 1926. A study of soil heterogeneity in experiment plots. Jour Agr Res, 33, 255-268. Tables 3, 5. https://naldc.nal.usda.gov/download/IND43967148/PDF

References

Garber, R. J. and T. C. McIlvaine and M. M. Hoover (1931). A Method of Laying Out Experimental Plats. Journal of the American Society of Agronomy, 23, 286-298, https://archive.org/details/in.ernet.dli.2015.229753/page/n299

Examples

## Not run: 

library(agridat)
  
  data(garber.multi.uniformity)
  dat <- garber.multi.uniformity

  libs(desplot)
  desplot(dat, oats ~ col*row,
          flip=TRUE, tick=TRUE, aspect=945/436, # true aspect
          main="garber.multi.uniformity oats")

  desplot(dat, wheat ~ col*row,
          flip=TRUE, tick=TRUE, aspect=945/436, # true aspect
          main="garber.multi.uniformity wheat")

  with(dat, cor(oats, wheat)) # = .37 matches Garber


## End(Not run)  

kwstat/agridat documentation built on April 19, 2024, 9:18 a.m.