Agriculture Reference
In-Depth Information
20
15
10
5
0
Humid 25C
Humid13C
Dry 25C
Dry 13C
Fig. 17
Changes of dry weight under varying humidity and root temperature.
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Humid 25C
Humid13C
Dry 25C
Dry 13C
Fig. 18
Changes of leaf area under varying humidity and root temperature
(at 55 days after planting).
Table 10
Nitrate and ammonium uptake (O moles gfw
-1
) as infl uenced by
temperature in growing rice seedlings.
Hours
NO
3
-uptake
NH
4
-uptake
15ºC
25ºC
15ºC
25ºC
1
2.0
2.5
5.0
7.0
2
3.0
5.0
11.0
11.0
4
3.5
15.0
15.0
20.0
5
5.0
22.0
19.0
28.0
7
5.0
33.0
20.0
35.0
In a water culture experiment (Table 10) the rice seedlings
showed no appreciable nitrate uptake at temperature below
15ºC, whereas appreciable ammonium uptake occurred at 15ºC,
although lowered passive absorption and complete inhibition
