Soil humidity as a productive conditioner of soybean culture through inoculation, co-inoculation and rooting

Abstract

In the soybean crop, the practice of inoculation is crucial for producing high yields. This is because biological nitrogen fixation (BNF) is the main supplier of the nutrient demand for this crop. However, a few environmental variables can also greatly influence the survival of the bacteria that control this process. In this context, the present work was performed to confirm the many ways in which soil moisture affects this process. In the field, we conducted two experiments at the times of the two sowing dates, 11/24/2015 and 12/17/2015, adopting the factorial 7 x 2 design, with four replications. The inoculation treatments included, non-inoculated (NI); not inoculated along with the nitrogen supplied at the 200 kg ha-1 (NI+N) dosage; inoculation with Bradyrhizobium [I (Brady)]; root enhancers (R); inoculation with Bradyrhizobium + root enhancers (I+R); co-inoculation with Bradyrhizobium + Azospirillum brasilense (I+Azo); co-inoculation with Bradyrhizobium + Azospirillum brasilense + root enhancers (I+Azo+R). The second factor included was the use or absence of a water jet (200 L ha-1) directed onto the seeds in the sowing furrow. Then estimations of the initial establishment of the plants, nodulation, and productivity components were measured. Water supplied to the sowing furrow had no effect on soybean nodulation and yield components. Co-inoculation promoted nodulation in soybean plants, particularly in dry mass of the nodules and number of nodules per plant.