Ammonia Volatilization from Urea-Application Influenced Germination and Early Seedling Growth of Dry Direct-Seeded Rice

Table 2

Ammonia volatilization from three different soils with ammonium sulfate, urea, and urea + NBPT in comparison with zero N input (control) in Petri dish incubation experiment.

Soil source	Ammonia volatilization^a (μg per Petri dish)
	Control	AS^b	Urea^b	Urea^b+NBPT^c
Soil I	0 c	0 c	4029 a	323 b
Soil II	0 b	0 b	4250 a	0 b
Soil III	0 c	0 c	1785 a	136 b

Within a row, means followed by different letters are significantly different at 0.05 probability level according to Least Significant Difference (LSD) test.
^aAmmonia volatilization was determined at four days after incubation.
^bThe rate of ammonium sulfate and urea was 0.15 g N per Petri dish.
^cThe rate of NBPT was 1.5 mg per Petri dish.