Results 211 to 220 of about 93,573 (258)

An empirical model for root water uptake

Field Crops Research, 2004
Soil water availability estimation is critical for assessing crop development and performance. During periods of soil water deficits, the capability of crop roots to extract soil water depends on the distribution and depth of its root system. Most water uptake models assume a relationship between root water extraction and root length density (RLD ...
J T Ritchie
exaly   +2 more sources

LINEAR ROOT WATER UPTAKE BY VEGETATION

Malaysian Journal of Civil Engineering, 2018
The performance of a simple model with a linear root water extraction term that varies with time is presented in this paper. The research is based on the use of a one-dimensional form of Richard’s Equation for unsaturated moisture flow including a sink term.
N. Ali N. Ali, S.W. Rees S.W. Rees
openaire   +1 more source

Modeling water uptake by roots

Irrigation Science, 1991
Most current models of the water uptake by plant roots from the soil profile solve the equation for flow of water in unsaturated soils. The boundary condition at the root-soil interface is represented, whether explicitly or implicitly by some kind of root distribution function. Such models have sufficient number of parameters so that they can be fitted
openaire   +1 more source

Nonlinear Root-Water Uptake Model

Journal of Irrigation and Drainage Engineering, 1996
Sound irrigation management requires information about root-water uptake patterns of different crops. In the existing literature, the extraction rate of soil moisture by the roots is assumed to be either constant or varying linearly with the root depth, during the crop period. However, both these models have limited application.
Chandra Shekhar P. Ojha, Amaresh K. Rai
openaire   +1 more source

Modeling Water Uptake by Plant Roots

Journal of Irrigation and Drainage Engineering, 1999
A mathematical model is developed that describes water uptake from soil by the roots of transpiring plants. Starting from a one-dimensional Richards equation with a root water extraction term, a partial differential equation predicting the moisture content in the soil profile is formulated.
Shashi Mathur, Sandhya Rao
openaire   +1 more source

An exponential root-water-uptake model

Canadian Journal of Soil Science, 1999
Macroscopic root-water-extraction models often do not adequately account for the non-uniform distribution of roots in the soil profile. We developed an exponential root-water-uptake model, which was derived from a measured root density distribution function. The model, incorporated in the Soil-Water-Atmosphere-Plant (SWAP) simulation model, was tested
K. Y. Li, J. B. Boisvert, R. De Jong
openaire   +1 more source

Water Uptake and Flow in Roots

1982
The loss of water by evaporation from the leaves of plants (transpiration) is an inevitable accompaniment of the photosynthetic absorption of carbon dioxide from the atmosphere. Water is absorbed from the soil by the roots to make good this transpirational loss.
openaire   +1 more source

A linear root water uptake model

Journal of Hydrology, 1988
A model of root water extraction is proposed, in which a linear variation of extraction rate with depth is assumed. Five crops are chosen for simulation studies of the model, and soil moisture depletion under optimal conditions from different layers for each crop is calculated. Similar calculations are also made using the constant extraction rate model.
openaire   +1 more source

Uptake of water from a Kandosol subsoil. II. Control of water uptake by roots

Plant and Soil, 2013
To test for the presence of an impediment to water flow at the soil-root interface. Wheat plants were grown in repacked and undisturbed field soil. Their transpiration rate, E, was varied in several steps from low to high and then back to low again, while the hydrostatic pressure in the leaf xylem, ψ xylem, was measured non ...
David M. Deery, John B. Passioura, Jason R. Condon, Asitha Katupitiya   +3 more
openaire   +1 more source

Modeling soil water movement with water uptake by roots

Plant and Soil, 1999
Soil water movement with root water uptake is a key process for plant growth and transport of water and chemicals in the soil-plant system. In this study, a root water extraction model was developed to incorporate the effect of soil water deficit and plant root distributions on plant transpiration of annual crops.
Jinquan Wu, Renduo Zhang, Shengxiang Gui
openaire   +1 more source