Inoculation of sugarcane with diazotrophic bacteria

• Main Authors: Nivaldo Schultz, Jeferson Alves da Silva, Jailson Silva Sousa, Rafael Cassador Monteiro, Renan Pedula Oliveira, Valfredo Almeida Chaves, Willian Pereira, Marinete Flores da Silva, José Ivo Baldani, Robert Michael Boddey, Veronica Massena Reis, Segundo Urquiaga
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Ciência do Solo 2014-04-01
• Series: Revista Brasileira de Ciência do Solo
• Subjects: Saccharum sp.; inoculante; fixação biológica de nitrogênio
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000200005&lng=en&tlng=en

The sugarcane industry, a strategic crop in Brazil, requires technological improvements in production efficiency to increase the crop energy balance. Among the various currently studied alternatives, inoculation with diazotrophic bacteria proved to be a technology with great potential. In this context, the efficiency of a mixture of bacterial inoculant was evaluated with regard to the agronomic performance and N nutrition of sugarcane. The experiment was carried out on an experimental field of Embrapa Agrobiologia, in Seropédica, Rio de Janeiro, using a randomized block, 2 × 3 factorial design (two varieties and three treatments) with four replications, totaling 24 plots. The varieties RB867515 and RB72454 were tested in treatments consisting of: inoculation with diazotrophic bacteria, N-fertilized control with 120 kg ha-1 N and absolute control (no inoculation and no N fertilizer). The inoculum was composed of five strains of five diazotrophic species. The yield, dry matter accumulation, total N in the shoot dry matter and the contribution of N by biological fixation were evaluated, using the natural 15N abundance in non-inoculated sugarcane as reference. The bacterial inoculant increased the stalk yield of variety RB72454 similarly to fertilization with 120 kg ha-1 N in the harvests of plant-cane and first ratoon crops, however the contribution of biological N fixation was unchanged by inoculation, indicating that the benefits of the inoculant in sugarcane may have resulted from plant growth promotion.