# wrc

0th

Percentile

##### Points of a water retention curve data set

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

Keywords
datasets, spatial
##### Usage
data(wrc)
##### 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.

##### 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)

##### References

MORAES, S. O. ; LIBARDI, P. L. ; REICHARDT, K. (1993) Problemas metodol<U+000E7A63>os na obten<e7><e3>o da curva de reten<e7><e3>o de <e1>gua 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 reten<e7><e3>o da <e1>gua do solo.. Scientia Agricola, Piracicaba, v. 50, n. 3, p. 393-402.

MORAES, S. O. ; LIBARDI, P. L. (1993) Variabilidade da <e1>gua dispon<ed>vel em uma terra roxa estruturada latoss<U+000ECA63>a. Scientia Agricola, Piracicaba, v. 50, n. 3, p. 393-402, 1993.

• wrc
##### Examples
# NOT RUN {
pr100 <- as.geodata(wrc, data.col=7)
summary(pr100)
plot(pr100)
# }

Documentation reproduced from package geoR, version 1.8-1, License: GPL (>= 2)

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