Multi-environment trial of corn with nitrogen fertilizer

Corn yield response to nitrogen

Format

A data frame with 54 observations on the following 4 variables.

nitro: nitrogen fertilizer, pound/acre
year: year
loc: location
yield: yield, bu/ac

Details

Experiments were conducted in eastern Oregon during the years 1950-1952.

Planting rates varied from 15,000 to 21,000 planter per acre.

Source

Albert S. Hunter, John A. Yungen (1955). The Influence of Variations in Fertility Levels Upon the Yield and Protein Content of Field Corn in Eastern Oregon. Soil Science Society of America Journal, 19, 214-218. https://doi.org/10.2136/sssaj1955.03615995001900020027x

References

James Leo Paschal, Burton Leroy French (1956). A method of economic analysis applied to nitrogen fertilizer rate experiments on irrigated corn. Tech Bull 1141. United States Dept of Agriculture. books.google.com/books?id=gAdZtsEziCcC&pg=PP1

Examples

if (FALSE) { # \dontrun{

library(agridat)
data(hunter.corn)
dat <- hunter.corn

dat <- transform(dat, env=factor(paste(loc,year)))

libs(lattice)
xyplot(yield~nitro|env, dat, type='b',
main="hunter.corn - nitrogen response curves")

} # }