wrc {geoR}

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 \times 10^2 Pa (atm)

Pr10

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

Pr60

a numeric vector, water content at a pressure of 60 mca – 6 \times 10^3 Pa (atm)

Pr100

a numeric vector, water content at a pressure of 100 mca – 1 \times 10^4 Pa (atm)

Pr306

a numeric vector, water content at a pressure of 306 mca – 3 \times 10^4 Pa (atm)

Pr816

a numeric vector, water content at a pressure of 816 mca – 8 \times 10^4 Pa (atm)

Pr3060

a numeric vector, water content at a pressure of 3060 mca – 3 \times 10^5 Pa (atm)

Pr15300

a numeric vector, water content at a pressure of 15300 mca – 1.5 \times 10^6 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 \times 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 \times 10^2, 1 \times 10^3, 6 \times 10^3, 1 \times 10^4, 3 \times 10^4, 8 \times 10^4, 3 \times 10^5, 1.5 \times10^6 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)