R: Points of a water retention curve data set

wrc {geoR} | R Documentation

## Points of a water retention curve data set

### Description

Soil density and measures of the water retention curve obtained at different pressures on a regular grid with 10x25 points spaced by 5 meters.

### Usage

    data(wrc)

### Format

A data frame with 250 observations on the following 11 variables.

`CoordX`

  a numeric vector with the X coordinates of the samples.

`CoordY`

  a numeric vector with the Y coordinate of the samples.

`Densidade`

  a numeric vector, soil density (g/cm^3)

`Pr5`

  a numeric vector, water content at a pressure of 5 mca – 5 x 10^2 Pa (atm)

`Pr10`

  a numeric vector, water content at a pressure of 10 mca – 1x10^3 Pa (atm)

`Pr60`

  a numeric vector, water content at a pressure of 60 mca – 6x10^3 Pa (atm)

`Pr100`

  a numeric vector, water content at a pressure of 100 mca – 1x10^4 Pa (atm)

`Pr306`

  a numeric vector, water content at a pressure of 306 mca – 3x10^4 Pa (atm)

`Pr816`

  a numeric vector, water content at a pressure of 816 mca – 8x10^4 Pa (atm)

`Pr3060`

  a numeric vector, water content at a pressure of 3060 mca – 8x10^5 Pa (atm)

`Pr15300`

  a numeric vector, water content at a pressure of 15300 mca – 1.5x10^6 Pa (atm)

### Details

Uniformity trial with 250 undisturbed soil samples collected at 25cm soil depth of spacing of 5 meters, resulting on a regular grid of 25 x 10 sampling points.

For each sampling point there are measurents of the soil density and water content obtained at eight pressures: 5, 10, 60, 100, 306, 816, 3060 and 15300 meters of column of water (mca), corresponding to 5 x 10^2, 1 x 10^3, 6 x 10^3, 1 x 10^4, 3 x 10^, 8 x 10^4, 3 x 10^5, 1.5 x 10^6 Pa.

The experiment aimed to use the water contents of the samples to estimate the water retention curve at the 250 data points.

See also the data-set `soil250` with soil chemistry properties measured at the same points.

### Source

MORAES, S.O. (1991) Heterogeneidade hidráulica de uma terra roxa estruturada. PhD Thesis. ESALQ/USP.

### References

MORAES, S. O. ; LIBARDI, P. L. ; REICHARDT, K. (1993) Problemas metodológicos na obtenção da curva de retenção de água pelo solo. Scientia Agricola, Piracicaba, v. 50, n. 3, p. 383-392.

MORAES, S. O. ; LIBARDI, P. L. ; REICHARDT, K. ; BACCHI, O. O. S. (1993) Heterogeneidade dos pontos experimentais de curvas de retenção da água do solo.. Scientia Agricola, Piracicaba, v. 50, n. 3, p. 393-402.

MORAES, S. O. ; LIBARDI, P. L. (1993) Variabilidade da água disponível em uma terra roxa estruturada latossólica. Scientia Agricola, Piracicaba, v. 50, n. 3, p. 393-402, 1993.

### Examples

    pr100 <- as.geodata(wrc, data.col=7)
    summary(pr100)
    plot(pr100)

[Package geoR version 1.7-5.2 Index]