Table 5.5 . DRAFT P2R WQ Risk Framework irrigation scheduling rules proposed to be applied .
Crop |
Stage |
Time Period |
|
|
( DAS ) |
Plant |
Establishment |
< 94 |
|
|
( TBC ) |
Delta Frequency ( minimum ) irrB
Delta Frequency ( minimum ) irrC / D
BRIA Frequency ( minimum ) irrB
BRIA Frequency ( minimum ) irrC / D
on days 2 , 30,60 , 93 Same as irrB on days 2 , 58 , 93 Same as irrB
FreqA 94-125 28 28 28 28 FreqB 125-180 14 14 14 14 FreqC 180-220 7 7 7 7 FreqD 220-350 7 7 7 7 FreqE > 350 14 7 14 7
Ratoon 1 Establishment < 88 on days 3 , 33 , 64 Same as irrB on days 3 , 33 , 64 Same as irrB FreqF 88-130 14 14 14 14 FreqG 130-290 7 7 10 10 FreqH > 290 14 7 14 10
Ratoon 2 Establishment < 79 on days 3 , 33 , 64 , 76 Same as irrB on days 3 , 33 , 64 , 76 Same as irrB FreqI 79-110 14 14 10 10 FreqJ 110-290 7 7 10 10 FreqK > 290 14 7 14 10 Ratoon 3 / 4 Establishment < 47 on days 3 , 23 , 36 Same as irrB on days 3,33 , Same as irrB
Irrigation Rates ( mm )*
Drydown period before harvest
FreqL 47-110 14 14 14 14 FreqM 47-290 7 7 10 10 FreqN > 290 14 7 14 10
40-200mm per irrigation
June-Aug-8weeks Sept onwards- 6weeks
40-200mm per irrigation
June-Aug-8weeks Sept onwards- 6weeks
40-150mm per irrigation
June-Aug-10weeks Sept / Oct-8weeks
* Note that the rates would be adjusted to meet the Production Indicator for the management class as specified above .
Capture of farm runoff / Recycling pits
The current rules for runoff capture during the dry season , shown in Table 5.6 , will continue to be implemented in the model .
Table 5.6 . P2R WQ Risk Framework dry season runoff capture rules for recycling pits .
40-150mm per irrigation
June-Aug-10weeks Sept / Oct-8weeks
ABCD |
P2R WQ Risk Framework strategy |
Dry season capture of runoff in |
|
|
model |
A
B
C
D
Capture all irrigation water + some rainfall . Storages are equipped with adequate pumping capacity and captured tailwater is rapidly re-used in the short term ( days / weeks ).
Capture all irrigation water . No irrigation tailwater leaves the farm ( tailwater from 100 per cent of farm area is captured ).
Capture ‘ most ’ irrigation water . The majority of irrigation tailwater is retained on-farm ( tailwater from 50-99 per cent of farm is captured ).
No recycling . The majority of irrigation tailwater is not retained on-farm ( less than 50 per cent of farm area is captured ).
100 per cent of runoff captured on irrigation days , 10 per cent of rainfall runoff
95 per cent of runoff captured on irrigation days
65 per cent of runoff captured on irrigation days
0 per cent of runoff captured
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