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Soil Water Uptake by Alfalfa 1
Author(s) -
Kohl R. A.,
Kolar J. J.
Publication year - 1976
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1976.00021962006800030030x
Subject(s) - medicago sativa , soil water , neutron probe , agronomy , water content , water potential , xylem , environmental science , soil horizon , soil science , chemistry , horticulture , biology , neutron , geology , neutron cross section , physics , geotechnical engineering , quantum mechanics , neutron temperature
Water uptake patterns of alfalfa ( Medicago sativa L.) assist us in understanding proposed models governing plant water uptake. The data in this paper are presented to elucidate some details of passive water uptake from profiles with nonuniform soil water distributions. Soil water content under an alfalfa seed crop was monitored with a neutron moisture probe. Alfalfa roots withdraw soil water in the lower portion of the root zone (where soil matric potentials were between −7 and −10 bars), while the upper portion of the profile was above −2 bars. This indicates that for passive water uptake to occur, large water potential differences must exist between the root xylem and the soil in the upper, moist portion of the profile. Plant water potential measurements support passive uptake.