Daily water use and reduced deficit irrigation files can be created and edited. The files can contain any values, not just daily water use - fruit diameter for example.
DWU files show the variation of crop daily
water use during the season. The values can come from standard department of agriculture
crop water use tables, or preferably from your own soil moisture readings
RDI files describe how you want the
water content in the root zone to vary relative to the refill point - wine grapes are
often dried out just before picking
The files can also be used in formulas. For example a site that is using about 10% more water than the average...
Site Formula: COTTON.DWU * 1.1
Files in this format can also be used to set upper and lower limits for scheduling. The values in the file can be either in mm above/below full or refill, or as a proportion (0-1) between refill and full - see scheduling
A season file is an ascii text file with at least 3 lines.
The first line is the start day, in 'days since Jan 1'
All other lines have the relative day number and the value
The actual day of year is calculated by adding the 'start day' to the 'relative day number'.
This is to allow the files to be easily used in different hemispheres - one of many silly ideas we have had.
Eaxmples...
| File | Date | Value |
|---|---|---|
273 |
first line - start day in 'days since Jan 1' 273 = 1 October |
|
40, 2.0 |
273 + 40 = 313 = 10 Nov | 2.0 mm/day |
60, 2.5 |
273 + 60 = 333 = 30 Nov | 2.5 mm/day |
80, 3.8 |
||
90, 5.0 |
273 + 90 = 363 = 28 December | 5.0 mm/day |
100, 6.0 |
273 + 100 = 373 = 8 = 8 January | 6.0 mm/day |
120, 8.0 |
||
130, 8.0 |
||
160, 5.5 |
||
180, 4.2 |
The dates must be in days, but the values can be any units. Prwin will display mm/day in in/ft or other user selected units set with
Season DWU files will work in any year because the date information is relative to Jan 1st, not to any particular year. To use the same data for crops with different planting dates, or to compare with data from another hemisphere, simply change the 'start date number' in the first line and save with a new file name.
The actual date may be in error from leap years.
Later version of Prwin and MLog allow other options
| File | Date | Value | Software |
|---|---|---|---|
1 Nov, 3.5 |
1st Nov (any year) - start day is ignored | 3.5 mm/day | PRW1, PRW2, MLOG |
1 Nov, REFILL + 0.1 * (FULL - REFILL) |
1st Nov | 10% between refill and full | PRW1, PRW2 |
PDATE+20, FULL-20 |
20 days after Planting Date | Full point - 20mm | PRW1, PRW2 |
DATE3, REFILL - 10 |
critical date 3 (e.g. Bud Burst) | 10 mm below refill | PRW1, PRW2 |
PRW1 = Probe for Windows v 1.0.220+
PRW2 = Probe for Windows 2
MLOG = Mlog v 2.1.033
MLOG and PRW2 allow more than 1 value columns. e.g.
1 Nov, 3.5, 2.9, 2.8
|
The columns could be DWU for different crops, or both the upper and lower limits for the same crop