Table 2.

The concentrations of nitrogen (N) sources used in each treatment.

Treatment	N Source	Concentration (g L−1)
A	Absent	-
B	NaNO3 (nitrate)	1.5
C		1.5 × 10−2
D		1.5 × 10−5
E	Fe-NH4-citrate (ammonium)	0.006
F		0.006 × 10−2
G		0.006 × 10−5