eden.potato: Potato yields in response to potash and nitrogen fertilizer

In kwstat/agridat: Agricultural Datasets

Potato yields in response to potash and nitrogen fertilizer

Description

Potato yields in response to potash and nitrogen fertilizer. Data from Fisher's 1929 paper Studies in Crop Variation 6. A different design was used each year.

Format

A data frame with 225 observations on the following 9 variables.

year

year/type factor

yield

yield, pounds per plot

block

block

row

row

col

column

trt

treatment factor

nitro

nitrogen fertilizer, cwt/acre

potash

potash fertilizer, cwt/acre

ptype

potash type

Details

The data is of interest to show the gradual development of experimental designs in agriculture.

In 1925/1926 the potato variety was Kerr's Pink. In 1927 Arran Comrade.

In the 1925a/1926a qualitative experiments, the treatments are O=None, S=Sulfate, M=Muriate, P=Potash manure salts. The design was a Latin Square.

The 1925/1926b/1927 experiments were RCB designs with treatment codes defining the amount and type of fertilizer used. Note: the 't' treatment was not defined in the original paper.

Source

T Eden and R A Fisher, 1929. Studies in Crop Variation. VI. Experiments on the response of the potato to potash and nitrogen. Journal of Agricultural Science, 19: 201-213.

References

McCullagh, P. and Clifford, D., (2006). Evidence for conformal invariance of crop yields, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Science, 462, 2119–2143. https://doi.org/10.1098/rspa.2006.1667

Examples

## Not run: 

library(agridat)
data(eden.potato)
dat <- eden.potato

# 1925 qualitative
d5a <- subset(dat, year=='1925a')
libs(desplot)
desplot(d5a, trt~col*row,
        text=yield, cex=1, shorten='no', # aspect unknown
        main="eden.potato: 1925 qualitative")
anova(m5a <- aov(yield~trt+factor(row)+factor(col), d5a)) # table 2

# 1926 qualitative
d6a <- subset(dat, year=='1926a')
libs(desplot)
desplot(d6a, trt~col*row,
        text=yield, cex=1, shorten='no', # aspect unknown
        main="eden.potato: 1926 qualitative")
anova(m6a <- aov(yield~trt+factor(row)+factor(col), d6a)) # table 4

# 1925 quantitative
d5 <- subset(dat, year=='1925b')
libs(desplot)
desplot(d5, yield ~ col*row,
        out1=block, text=trt, cex=1, # aspect unknown
        main="eden.potato: 1925 quantitative")

# Trt 't' not defined, seems to be the same as 'a'
libs(lattice)
dotplot(trt~yield|block, d5,
        # aspect unknown
        main="eden.potato: 1925 quantitative")
anova(m5 <- aov(yield~trt+block, d5)) # table 6

# 1926 quantitative
d6 <- subset(dat, year=='1926b')
libs(desplot)
desplot(d6, yield ~ col*row,
        out1=block, text=trt, cex=1, # aspect unknown
        main="eden.potato: 1926 quantitative")
anova(m6 <- aov(yield~trt+block, d6)) # table 7

# 1927 qualitative + quantitative
d7 <- droplevels(subset(dat, year==1927))
libs(desplot)
desplot(d7, yield ~ col*row,
        out1=block, text=trt, cex=1, col=ptype, # aspect unknown
      main="eden.potato: 1927 qualitative + quantitative")

# Table 8.  Anova, mean yield tons / acre
anova(m7 <- aov(yield~trt+block+ptype + ptype:potash, d7))
libs(reshape2)
me7 <- melt(d7, measure.vars='yield')
acast(me7, potash~nitro, fun=mean) * 40/2240 # English ton = 2240 pounds
acast(me7, potash~ptype, fun=mean) * 40/2240


## End(Not run)

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