Responses to inoculation have shown that inoculation is justified in soil where has never been grown soybean, such is the case of El Rincón de Monagas (94° 41' 35" N, 63° 04' 38" W and 39 m.a.s), Monagas State, Venezuela. In this context, two inoculants types of Bradyrhizobium japonicum (RIZO-LIQ, water-based product and RIZOPLUS SUPER, peat-based product, both from RIZOBACTER Argentina, S.A.) were tested in soybean variety Tracaja (EMBRAPA, Brazil) throughout growth (shoot height and dry weight, root length and dry weight, and leaf area) and nodulation (red nodule number and dry weight) parameters measurements. Chemical fertilizer as NPK (10-10-10) was added at planting which supplied 20kg nitrogen/ha as starter dose. Also was applied Legumol (8,0% Mo, 0,7% Co, 5,0% Zn, 0,5% B, 0,5% Cu and 0,1% Mn), at a rate of 200g/g seed as source of micronutrients. Data were subjected to variance analysis, using the statistical package Statistix and to the least significant difference (LSD) test at 5% probability level to compare treatment means. The inoculants combination (RIZOPLUS + RIZO-LIQ) treatment resulted more favorable to shoot height and dry weight and leaf area; similarly behaved red nodule number and dry weight. The inoculants combination (RIZO-LIQ + RIZOPLUS) was more favorable for growth and nodulation of soybean variety Tracaja. In relation to the results, the factors bacterial number and competitiveness are discussed.
