Table 5: Analysis of variance summary and mean season-long nitrous oxide (N2O) emissions, rice yield, above- and belowground and total dry matter (DM), above- and belowground nitrogen (N) concentration and uptake, grain N concentration and uptake, total N uptake, and N2O emissions intensity for four fertilizer-N treatments [i.e., optimum plus one split (OPOS), half optimum plus two splits (HOPTS), optimum plus two splits (OPTS), and unamended control (UC)] from rice grown in a silt-loam soil under furrow-irrigation in the greenhouse.
|
Property |
P |
Fertilizer-N treatments |
Overall mean |
|||
|
OPOS |
HOPTS |
OPTS |
UC |
|||
|
Emissions (kg ha-1 season-1) |
0.60 |
0.65 a |
0.63 a |
0.61 a |
0.42 a |
0.579 |
|
Yield (Mg ha-1) |
< 0.01 |
11.1 a |
11.3 a |
8.7 a |
0.9 b |
- |
|
Aboveground DM (Mg ha-1) |
< 0.01 |
19.0 a |
19.3 a |
16.1 a |
6.4 b |
- |
|
Belowground DM (Mg ha-1) |
< 0.01 |
11.6 a |
13.3 a |
13.3 a |
2.4 b |
- |
|
Total DM (Mg ha-1) |
< 0.01 |
41.0 a |
43.4 a |
37.1 a |
11.0 b |
- |
|
Aboveground N (g g-1) |
0.06 |
0.012 a |
0.014 a |
0.011 a |
0.009 a |
0.011 |
|
Belowground N (g g-1) |
0.49 |
0.004 a |
0.004 a |
0.003 a |
0.004 a |
0.004 |
|
Aboveground N (kg ha-1) |
< 0.01 |
221.6 ab |
267.5 a |
170.3 b |
61.0c |
- |
|
Belowground N (kg ha-1) |
< 0.01 |
47.3 a |
49.0 a |
43.1 a |
10.7 b |
- |
|
Grain N (g g-1) |
< 0.01 |
0.020 a |
0.020 a |
0.019 a |
0.016 b |
- |
|
Grain N (kg ha-1) |
< 0.01 |
201.7 a |
205.1 a |
145.9 a |
33.5 b |
- |
|
Total N (kg ha-1) |
< 0.01 |
473.7 ab |
521.9 a |
358.9 b |
105.0 c |
- |
|
Intensity (kg N2O Mg seed yield-1) |
0.02 |
0.06 b |
0.06 b |
0.07 b |
0.19 a |
- |