Evaluation of TDR Use to Monitor Water Content in Stem of Lemon Trees and Soil and Their Response to Water Stress
Evaluation of TDR Use to Monitor Water Content in Stem of Lemon Trees and Soil and Their Response to Water Stress
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DOI：
10.2136/sssaj2003.4370
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发表时间：
2003-03
影响因子：
2.9
通讯作者：
A. Nadler;E. Raveh;U. Yermiyahu;Stephen R. Green
中科院分区：
文献类型：
--
作者：
A. Nadler;E. Raveh;U. Yermiyahu;Stephen R. Green
The purpose of the study was to compare the response of TDR- determined stem (θ stem ) and soil (θ soil ) water content to different irrigation managements. θ stem (L L -1 ) was measured with three-rods TDR probes (70 mm) installed vertically or horizontally into predrilled holes in the trunk of 5-yr-old lemon [Citrus limon (L.) Burman f.] trees in a semiarid region (Israel). Four irrigation treatments were established to deliver 100% (full), half of this amount on one side of the tree (50%), same amount as in 50% but applied to alternate sides (3-wk intervals) of the tree (split), and 0% (dry) of the orchard's normal irrigation volume (typically 150-200 m 3 wk -1 ha -1 ). Treated sewage water (σ w = 0.9 dS m -1 ) was used to irrigate the trees for 75 d (end of June and mid September). Changes in θ soil , and θ stem were monitored at weekly intervals. Leaf water potential and temperature measurements were used to verify the achieved water stress levels. θ stem of the full treatment fluctuated by about 0.02 to 0.03 L L -1 above and below the prestress reference level (beginning of the season). In contrast, θ stem of the 50% treatment declined (by about 0.07 L L -1 ) steadily over the season. For the split and dry treatments, θ stem decreased by about 0.12 L L -1 relative to the reference level. θ soil and θ stem values suggest that some surplus irrigation was applied to the full and 50% treatments. It was found that water stress was reflected in TDR-measured θ stem changes but that these changes were too small for routine irrigation control.
