Table 2. Grain yield, plant N content, N derived from fertilizer (NDFF) and ¹⁵N recovery (NRE, %) by corn for all N fertilization treatments.

Treatments	Grain yield	Plant N content	NDFF	NRE
	Mg ha-1	kg ha-1		(%)
Oat tillering	11.8	249 c	32 c	18 c
Pre-planting	12.8	276 bc	62 b	37 b
Corn planting	12.6	273 bc	59 b	35 b
Top dressing V3	12.7	287 ab	85 a	51 a
Top dressing V3/V6	12.1	302 a	92 a	55 a
Average	12.4	278	66	39
N application timings (NAT)	ns	**	***	***

ns = not significant

** significant at less than 0.1% and

*** significant at less 0.001% probability of error by the F test. Lowercase letters compare the means in the same column.