Combining microorganisms in inoculants is agronomically important but industrially challenging: case study of a composite inoculant containing Bradyrhizobium and Azospirillum for the soybean crop

AMB Express

Table 5 Parameters evaluated in soybean cultivar BRS 1010IPRO with different treatments of inoculation with Bradyrhizobium and co-inoculation with Bradyrhizobium and Azospirillum in field trials performed in first-year cropping areas, without naturalized population of compatible soybean bradyrhizobia, in Lutécia-SP e Paranavaí-PR, Brazil

Treatment^a	Stage V5					Physiological maturity
	Nodulation		Shoot dry weight	N in shoot		N in grain		Grain yield	Mass of 100 grains
	n^o plant⁻¹	mg plant⁻¹	g plant⁻¹	Content g kg⁻¹	Total mg plant⁻¹	Content g kg⁻¹	Total kg ha⁻¹	kg ha⁻¹	g
Lutécia (SP)
T1—Control-N	0.0 b^b	0.0 c	6.71 b	21.0^n.s.b	140.9 b	38.3 c	61 c	1601 c	14.4 d
T2—Control + 200 kg N	0.0 b	0.0 c	9.53 a	23.9	227.7 a	43.8 b	142 b	3244 b	15.7 c
T3—Peat Brady	12.5 a	54.7 a	4.73 b	25.3	119.7 b	52.9 a	215 a	4059 a	17.2 b
T4—Liquid Brady	4.9 b	30.5 b	4.70 b	22.0	103.4 b	51.6 a	181 a	3500 b	15.5 c
T5—Single Brady + Single Azo (trademark)	10.6 a	30.3 b	5.71 b	21.0	119.9 b	51.7 a	211 a	4086 a	18.0 a
T6—Composite inoculant Brady + Azo	10.5 a	33.8 b	6.02 b	25.8	155.3 b	50.7 a	208 a	4100 a	17.7 ab
p value	0.001	0.001	0.019	0.10	0.009	0.001	0.001	0.001	0.001
Paranavaí (PR)
T1—Control—N	0.1 b	0.5 b	3.00 b	17.1 b	51.3 b	50.0 b	110 b	2202 d	12.6 a
T2—Control + 200 kg N	0.1 b	0.8 b	5.34 a	17.8 b	95.0 a	41.7 c	107 b	2574 cd	12.8 a
T3—Peat Brady	13.2 a	101.0 a	3.62 b	22.1 a	80.0 ab	54.0 a	157a	2904 bc	11.8 b
T4—Liquid Brady	8.5 a	74.2 a	3.60 b	21.0 a	75.6 ab	51.0 ab	143 a	2800 bc	11.5 b
T5—Single Brady + Single Azo (trademark)	10.7 a	76.2 a	4.32 ab	20.3 a	87.7 ab	52.9 a	166 a	3140 ab	12.5 a
T6—Composite inoculant Brady + Azo	8.6 a	77.6 a	3.92 ab	21.2 a	83.1 ab	52.0 a	181 a	3491 a	12.4 a
p value	0.001	0.001	0.038	0.007	0.097	0.001	0.001	0.001	0.003

^aT3 e T4, peat and liquid inoculant with Bradyrhizobium spp. strains SEMIA 5079 + SEMIA 5080, applied to supply 1.2 × 10⁶ cells seed⁻¹; T5, T4 + liquid inoculant with A. brasilense strains Ab-V5 + Ab-V6 applied to supply 1.2 × 10⁵ cells seed⁻¹; T6, composite inoculant developed in this study, with B. diazoefficiens strain SEMIA 5080 (1.2 × 10⁶ cells seed⁻¹) and A. brasilense strain Ab-V6 (1.2 × 10⁵ cells seed⁻¹)
^bData represent the means of six replicates and when followed by different letters, within each column, are statistically different (Duncan, p < 5% or 10%; n.s., statistically non-significant)