Uptake of water from a Kandosol subsoil: I. Determination of soil water diffusivity
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To determine soil water diffusivity, D(θ), on undisturbed field soil at medium to low water content (suction range from 10 to 150 m of water), for the purpose of modeling the uptake of water by plant roots.
The method is based on the analysis of one-step outflow induced by a turbulent stream of dry air over the exposed end of a soil core, with the other end of the core enclosed. The outflow is measured through time as the change in the weight of the core as it sits on a recording balance. D(θ) is calculated by deconvoluting the measured outflow function.
Over the suction range of 10 to 150 m of water, D(θ) calculated on the undisturbed soil ranged from 20 × 10−9 to 10 × 10−9 [m2 s−1], substantially higher than other published estimates over this range in suction.
These unusually large values cast doubt on the view that flow of water to roots limits uptake of water from the targeted subsoil.
KeywordsRoot water uptake Plant water uptake Undisturbed soil Outflow Evaporation Numerical analysis One-dimensional flow equation
DD received a PhD scholarship from the Cooperative Research Centre for Irrigation Futures and a PhD top-up from the CSIRO Water for Healthy Country flagship. This manuscript was written while DD received a writing up award from Charles Sturt University.
- Campbell GS (1985) Soil physics with BASIC: transport models for soil-plant systems. Developments in soil science, vol 14. Elsevier, AmsterdamGoogle Scholar
- Conte SD, De Boor C (1972) Elementary numerical analysis: an algorithmic approach. International series in pure and applied mathematics, 2nd edn. McGraw-Hill, New YorkGoogle Scholar
- Isbell RF (2002) The Australian soil classification, vol 4. Australian soil and land survey handbook series. CSIRO Publishing, MelbourneGoogle Scholar
- Jordan WR, Miller FR (1980) Genetic Variability in Sorghum Root Systems: Implication for Drought Tolerance. In: Turner NC, Kramer PJ (eds) Adaptation of Plants to Water and High Temperature Stress. Wiley Interscience, New York, pp 383–399Google Scholar
- Keating BA, Carberry PS, Hammer GL, Probert ME, Robertson MJ, Holzworth D, Huth NI, Hargreaves JNG, Meinke H, Hochman Z, Mclean G, Verburg K, Snow V, Dimes JP, Silburn M, Wang E, Brown S, Bristow KL, Asseng S, Chapman S, Mccown RL, Freebairn DM, Smith CJ (2003) An overview of Apsim, a model designed for farming systems simulation. Eur J Agron 18(3–4):267–288CrossRefGoogle Scholar
- Keffer D (1999) ChE 505 Library of MATLAB® Subroutines. http://clausius.engr.utk.edu/che505/text/codes.html. Accessed 20 October 2006
- Matano C (1933) On the relation between the diffusion-coefficients and concentrations of solid metals (The Nickel-Copper System). Jpn J Phy 8:109–113Google Scholar
- Passioura JB, Angus JF (2010) Improving Productivity of Crops in Water-Limited Environments. In: Sparks DL (ed) Advances in Agronomy, Vol 106, vol 106. Advances in Agronomy. pp 37–75Google Scholar
- Philip JR (1955) The concept of diffusion applied to soil water. Proc Nat Acad Sci Ind A 24:93–104Google Scholar
- Press WH, Flannery BP, Teukolsky SA, Vetterling WT (1986) Numerical recipes: The art of scientific computing. Cambridge University Press, CambridgeGoogle Scholar
- Ritchie JT (1985) A user-oriented model of the soil water balance in wheat. In: Wheat growth and modelling/edited by W. Day and R. K. Atkin. NATO ASI series: series A. Life sciences, vol v.86. Plenum in cooperation with NATO Scientific Affairs Division, New York, pp 293–305Google Scholar
- Rose DA (1968) Water movement in porous materials III. Evaporation of water from soil. Br J Appl Phys 1(2):1779–1791Google Scholar
- Schultz JE (1972) The effect of surface treatments on soil water storage and yield of wheat. Aust J Exp Agric Anim Husb 12(56)Google Scholar
- Walter CJ, Barley KP (1974) The Depletion of Soil Water by Wheat at Low, Intermediate, and High Rates of Seeding. Transactions, 10th International Congress of Soil Science, I:150–158Google Scholar
- Zia-ul-Haque (1990) A Computerized One-Step Outflow Method for Measurement of Soil Water Diffusivity. Soil physics: application under stress environments Proceedings of the International Symposium on Applied Soil Physics in Stress Environments, Islamabad, Pakistan, 22–26 January 1989:70–77Google Scholar