Sentek Diviner 2000, Руководство пользователя

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Part 1—The Diviner 2000 display unit and probe
Irrigation scheduling using Diviner 2000 data
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The onset of crop water stress
Figure 19—Onset of crop water stress
Figure 19 shows the soil daily soil water change dynamics after an
irrigation event. Initially the steps are relatively even indicating a non-
stressed soil moisture conditions for the crop.
Below the line marked Onset of crop water stress you can see a steady
decline of daily use of water. Below this line, the daily use of water is more
than 50 % less than that used the days above the line.
The Onset of Crop water Stress line is defined as:
The soil moisture content in the plant root zone when the first observable
slow down of the maximum daily crop water use rate after irrigation or
rainfall occurs.
The concept of Refill Point is a soil water budget level usually a notch
above the Onset of Crop Water Stress threshold level.
This information shows when irrigation is needed to prevent crop water
stress.
How to determine full point
To determine Full Point you need to find the depth of:
•
the irrigation
•
the active root zone.
Figures 20–23 show how to determine Full Point.