Seed germination percentage, shoot fresh weight, root fresh weight, and root tip number of rice variety Apo grown in three different soils with ammonium sulfate, urea, and urea + NBPT in comparison with zero N input (control) in Petri dish incubation experiment 2. The presoaked seeds were not in contact with soil but exposed to ammonia gas volatilized from soils.
| Parameter||Control||ASa||Ureaa||Ureaa + NBPTb|
|Soil I |
|Seed germination percentage (%)||100 a||98 a||90 a||100 a|
|Shoot FW (g per Petri dish)||0.16 a||0.17 a||0.15 a||0.15 a|
|Root FW (g per Petri dish)||0.17 a||0.14 b||0.01 c||0.15 ab|
|Root tip number per Petri dish||22 b||32 a||2 c||23 b|
|Seed germination percentage (%)||100 a||98 a||94 a||100 a|
|Shoot FW (g per Petri dish)||0.15 a||0.17 a||0.15 a||0.17 a|
|Root FW (g per Petri dish)||0.14 a||0.12 a||0.05 b||0.15 a|
|Root tip number per Petri dish||27 a||26 a||5 b||23 a|
|Seed germination percentage (%)||100 a||94 a||98 a||98 a|
|Shoot FW (g per Petri dish)||0.14 b||0.16 b||0.19 a||0.16 b|
|Root FW (g per Petri dish)||0.12 b||0.07 c||0.07 c||0.15 a|
|Root tip number per Petri dish||24 b||7 c||5 c||27 a|
|Within a row, means followed by different letters are significantly different at 0.05 probability level according to Least Significant Difference (LSD) test.|
aThe rate of ammonium sulfate and urea was 0.15 g N per Petri dish.
bThe rate of NBPT was 1.5 mg per Petri dish.