Conventional inoculants and biological protector, co-inoculation and nitrogen fertilization in soybean

Résumé

There is little information that supports the new technology of inoculants with biological protectors and indecates the results in soybean crop. In order to evaluate the morphophysiological responses of soybean crop to conventional inoculants, inoculants with protectors, co-inculation with Azospirillum brasilense and at increasing doses of N. The treatments consisted of: Control; Bradyrhizobium elkanii + biological protector; Bradhyrizobium elkanii + Bradhyrizobium japonicum + biological protector; Bradyrhizobium elkanii; Bradyrhizobium elkanii + co-inoculation with Azospirillum brasilense; Bradyrhizobium elkanii + biological protector + co-inoculation with Azospirillum brasilense; Bradyrhizobium elkanii + Bacillus amyloliquefaciens + biological protector; Dose 20 kg ha-1 of N; Dose N 40 kg ha-1 and Dose N 60 kg ha-1 of N. Nodulation, chlorophyll a, b and total content, nitrogen content in leaf tissue and grains were evaluated thousand grain mass and productivity were evaluated. The biological agents tested in the experiment provided an increase in the number of nodules and an increase in the mass of 1,000 grains when compared nitrogen fertilization. The treatments with nitrogen fertilization, compared to the treatments with inoculation, were higher for chlorophyll a, b and total contents. Long-life inoculants, in the absence and presence of coinoculation in seed treatment, demonstrated efficiency in number of nodules and in the supply of N in soybean crop, with superior responses on the non-inoculated control, even in soil with initial concentration 1,510 10-4 bacteria cells per gram of soil. Long-life inoculants offer greater practicality to the rural producer and demonstrated efficiency in the supply of N to soybean crop.