Effect of biofertilizers application on the growth of Eucalyptus grandis seedlings under greenhouse conditions

To investigate the effect of biofertilizers on the growth and yield of Eucalyptus grandis seedlings, greenhouse experiments were performed applying fertilizers based on agricultural byproducts, inoculated with nitrogen-fixing bacteria of the genera Azotobacter spp and Azospirillum spp. For the biofertilizers formulation, a nitrogen-fixing bacteria consortium was inoculated, and the experimental design was a 2 x 2 x 2 factorial arrangement, the factors were nitrogen source (NS: chicken manure), source of carbon (CS: eucalyptus leaf litter) and source of micronutrients (RS: rhizospheric soil) with two dose levels, inoculated with a consortium of Azotobacter spp and Azospirillum spp. The optimal time production of the best biofertilizers was 30 days, with the highest density of Azospirillum (9.23 x 10(6) CFU center dot g(-1)) and Azotobacter (19.3 x 10(6) CFU center dot g(-1)), and total nitrogen contents in the range of 2.15-5.64%, released into the biofertilizers with chicken manure and bioaugmented with the bacterium consortium. The treatment with the highest dose of biofertilizer, 500 g, showed the most significant effect on seedling development, increasing growth, stimulating rooting and the highest increase in leaf number. The results show that biofertilizers contributed to Eucalyptus grandis crop yield, and biofertilizers are proposed as an alternative for implementing sustainable soil management in the forest sector.