waynick.soil {agridat} | R Documentation

## Soil nitrogen and carbon in two fields

### Description

Soil nitrogen and carbon in two fields

### Format

A data frame with 200 observations on the following 6 variables.

`field`

  field name, 2 levels

`sample`

  sample number

`x`

  x ordinate

`y`

  y ordinate

`nitro`

  nitrogen content, percent

`carbon`

  carbon content, percent

### Details

Two fields were studied, one at University Farm in Davis, the other near Oakley. The Davis field is silty clay loam, the Oakley field is blow sand.

### Source

Waynick, Dean, and Sharp, Leslie. (1918). Variability in soils and its significance to past and future soil investigations, I-II. University of California press. http://archive.org/details/variabilityinsoi45wayn

### Examples

    data(waynick.soil)
    dat <- waynick.soil

    # Strong relationship between N,C
    require(lattice)
    xyplot(nitro~carbon|field, data=dat, main="waynick.soil")

    # Spatial plot
    if(require(sp) & require(gstat)){
    d1 <- subset(dat, field=="Davis")
    d2 <- subset(dat, field=="Oakley")
    coordinates(d1) <- data.frame(x=d1$x, y=d1$y)
    coordinates(d2) <- data.frame(x=d2$x, y=d2$y)
    spplot(d1, zcol = "nitro", cuts=8, cex = 1.6,
           main = "waynick.soil - Davis field - nitrogen",
           col.regions =  bpy.colors(8), key.space = "right")

    # Variogram
    v1 <- gstat::variogram(nitro~1, data=d1)
    plot(v1, main="waynick.soil - Davis field - nitrogen") # Maybe hasn't reached sill
    }

[Package agridat version 1.16 Index]