Table 3.

Effect of phosphorus (P) source, P level, and addition of phosphate-solubilizing bacteria (PSB) on nodulation and nitrogen fixation in mungbean.

Treatment	Number of nodules plant−1	Fresh weight of nodules plant−1 (g)	Dry weight of nodules plant−1(g)	Amount of N2 fixed (kg ha−1)
Control	22	1.27	0.37	35.86
All treatments	29	1.40	0.52	105.64
Significance level	∗∗	∗	∗∗	∗∗
P source (PS):
Single superphosphate	27b†	1.30b	0.52	94.34
Rock phosphate	30a	1.46a	0.49	129.95
Significance level	∗∗	∗∗	ns	∗∗
P level (PL):
45 kg ha−1	28b	1.34	0.48	107.16
90 kg ha−1	30a	1.42	0.53	117.13
Significance level	∗	ns	ns	∗∗
PSB addition:
Without PSB	27b	1.30b	0.47b	93.11
With PSB	31a	1.46a	0.54a	131.18
Significance level	∗∗	∗∗	∗∗	∗∗
Interactions:	significance level
PS x PL	ns	ns	ns	ns
PS x PSB	ns	ns	ns	∗∗
PL x PSB	ns	ns	ns	ns
PS x PL x PSB	ns	ns	ns	∗∗

^†Different letters after values indicate statistically significant difference (LSD test) at ∗P < 0.05; ∗∗P < 0.01, ns = non-significant.