llwr_llmpr | R Documentation |
A graphical solution and calculation of the least limiting water range and least limiting water matric potential range, including the corresponding the water content and water tensions limits.
llwr_llmpr(thetaR, thetaS, alpha, n, d, e, f = NULL, critical.PR, PD, Bd = NULL, h.FC, h.PWP, air.porosity, labels = c("AIR", "FC", "PWP", "PR"), ylab = "", graph1 = TRUE, graph2 = FALSE, ...)
thetaR |
the residual water content, m^3 m^{-3} |
thetaS |
the water content at saturation , m^3 m^{-3} |
alpha |
the scale parameter of the van Genuchten's model, hPa^{-1} |
n |
the shape parameter of the van Genuchten's model |
d |
a parameter of Busscher soil penetration resistance model. See details. |
e |
a parameter of Busscher soil penetration resistance model. See details. |
f |
a parameter of Busscher soil penetration resistance model. See details. |
critical.PR |
the limiting value of soil penetration resistance, MPa |
PD |
particle density, Mg m^{-3} |
Bd |
the bulk density to be displayed at bottom of the graph (optional), Mg m^{-3} |
h.FC |
the value of water tension at field capacity, hPa |
h.PWP |
the value of water tension at wilting point, hPa |
air.porosity |
the volumetric air-filled porosity |
labels |
the labels to h.FC, h.PWP, air.porosity and critical.PR |
ylab |
a title for the y-axis |
graph1 |
logical; if TRUE (default) a graphical solution for the Least Limiting Water Range is displayed |
graph2 |
logical; if TRUE (default) a graphical solution for the Least Limiting Matric Potential Range is displayed |
... |
Further graphical arguments |
The penetration resistance model, as presented by Busscher (1990), is given by PR = d * θ^{e} * BD^{f}. In this model, BD (bulk density) is calculated from thetaS (soil total porosity) and PD (particles density), i.e., BD = PD * thetaS^{-1}. If the argument f is not passed, the model becomes PR = d * θ^{e} .
A list of the LLWR and LLMPR, including the corresponding the water content and water tensions limits.
Renato Paiva de Lima <renato_agro_@hotmail.com>
Leon, H. N., Almeida, B. G., Almeida, C. D. G. C., Freire, F. J., Souza, E. R., Oliveira, E. C. A., Silva, E. P. 2019. Medium-term influence of conventional tillage on the physical quality of a Typic Fragiudult with hardsetting behavior cultivated with sugarcane under rainfed conditions. Catena, 175: 37-46.
Busscher, W. J. 1990. Adjustment of flat-tipped penetrometer resistance data to common water content. Transactions of the ASAE, 3: 519-524.
van Genuchten, M. T. 1980. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils 1. Soil Science Society of America journal, 44: 892-898.
Silva et al. 1994. Characterization of the least limiting water range of soils. Soil Science Society of America Journal, 58: 1775-1781.
Assouline, S., Or, D. 2014. The concept of field capacity revisited: Defining intrinsic static and dynamic criteria for soil internal drainage dynamics. Water Resources Research, 50: 4787-4802.
Millington, R. J., Quirk, J. P. 1961. Permeability of porous solids. Transactions of the Faraday Society, 57: 1200-1207.
Dexter, A. R., Czyz, E. A., Richard, G. 2012. Equilibrium, non-equilibrium and residual water: consequences for soil water retention. Geoderma, 177: 63-71.
Moraes, M. T., Bengough, A. G., Debiasi, H., Franchini, J. C., Levien, R., Schnepf, A., Leitner, D., 2018. Mechanistic framework to link root growth models with weather and soil physical properties, including example applications to soybean growth in Brazil. Plant and Soil, 428: 67-92.
# Parameters from Leon et al. (2018), for usual physical restrictions threshold llwr_llmpr(thetaR=0.1180, thetaS=0.36, alpha=0.133, n=1.30, d=0.005, e=-2.93, f=3.54, PD=2.65, critical.PR=4, h.FC=100, h.PWP=15000, air.porosity=0.1, labels=c("AFP", "FC","PWP", "PR"), graph1=TRUE,graph2=FALSE, ylab=expression(psi~(hPa)), ylim=c(15000,1)) mtext(expression("Bulk density"~(Mg~m^-3)),1,line=2.2, cex=0.8) llwr_llmpr(thetaR=0.1180, thetaS=0.36, alpha=0.133, n=1.30, d=0.005, e=-2.93, f=3.54, PD=2.65, critical.PR=4, h.FC=100, h.PWP=15000, air.porosity=0.1, graph1=FALSE,graph2=TRUE, labels=c("Air-filled porosity", "Field capacity", "Permanent wilting point", "Penetration resistance"), ylim=c(0.1,0.30), ylab=expression(theta~(m^3~m^-3))) mtext(expression("Bulk density"~(Mg~m^-3)),1,line=2.2, cex=0.8) # Without bulk density effects in Busscher's model (i.e. f=NULL) llwr_llmpr(thetaR=0.1180, thetaS=0.36, alpha=0.133, n=1.30, d=0.0165, e=-2.93, PD=2.65, critical.PR=3, h.FC=100, h.PWP=15000, air.porosity=0.1, graph1=TRUE,graph2=FALSE,ylim=c(15000,1), ylab=expression(psi~(hPa))) mtext(expression("Bulk density"~(Mg~m^-3)),1,line=2.2, cex=0.8) llwr_llmpr(thetaR=0.1180, thetaS=0.36, alpha=0.133, n=1.30, d=0.0165, e=-2.93, PD=2.65, critical.PR=3, h.FC=100, h.PWP=15000,air.porosity=0.1, graph1=FALSE,graph2=TRUE, ylim=c(0.1,0.30), ylab=expression(theta~(m^3~m^-3))) mtext(expression("Bulk density"~(Mg~m^-3)),1,line=2.2, cex=0.8) # Parameters from Leon et al. (2018), calculated physical restrictions threshold thetaR <- 0.1180 thetaS <- 0.36 alpha <- 0.133 n <- 1.30 clay.content <- 15 # clay content 15 % mim.gas.difusion <- 0.005 root.elongation.rate <- 0.3 # root elogation rate 30% FC <- (1/alpha)*((n-1)/n)^((1-2*n)/n) # Assouline and Or (2014) PWP <- 10^(3.514 + 0.0250*clay.content) # Dexter et al. (2012) AIR.critical <- (mim.gas.difusion*(thetaS)^2)^(1/(10/3)) # Millington and Quirk (1961) PR.critical <- log(root.elongation.rate)/-0.4325 # Moraes et al. (2018) llwr_llmpr(thetaR=thetaR, thetaS=thetaS, alpha=alpha, n=n, d=0.005, e=-2.93, f=3.54, PD=2.65,ylim=c(15000,1), critical.PR=PR.critical, h.FC=FC, h.PWP=PWP, air.porosity=AIR.critical, graph1=TRUE,graph2=FALSE, ylab=expression(psi~(hPa))) mtext(expression("Bulk density"~(Mg~m^-3)),1,line=2.2, cex=0.8) llwr_llmpr(thetaR=thetaR, thetaS=thetaS, alpha=alpha, n=n, d=0.005, e=-2.93, f=3.54, PD=2.65, critical.PR=PR.critical, h.FC=FC, h.PWP=PWP, air.porosity=AIR.critical, graph1=FALSE,graph2=TRUE, ylim=c(0.1,0.30), ylab=expression(theta~(m^3~m^-3))) mtext(expression("Bulk density"~(Mg~m^-3)),1,line=2.2, cex=0.8) # End (not run)
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