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Root Water Uptake and Soil Water Distribution: Test of an Availability Concept
Author(s) -
Lascano R.J.,
Bavel C.H.M.
Publication year - 1984
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1984.03615995004800020002x
Subject(s) - transpiration , environmental science , soil water , soil science , root system , water potential , agronomy , botany , biology , photosynthesis
An experimental test was made of the hypothesis that the fractional water uptake by the root system from a soil layer is proportional to the root density and to the difference between the water potential in that layer and the mean leaf water potential. This theory adequately explained the water uptake by a cotton root system that was divided over a wet and a dry soil compartment. It was also established that the absolute rate of water uptake from each compartment could be accurately calculated from the measured potential difference between soil and plant leaf, and from a separately measured plant hydraulic resistance, which was shown to have a value of 0.67 × 10 9 s, independent of transpiration rate.