Interação entre bactérias diazotróficas e doses de n-fertilizante na cultura da cana-de-açúcar

• Autor(a) principal: Oliver, Rodrigo [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/113792
• topic: Cana-de-açúcar - Inoculação; Plantas - Efeito do nitrogenio; Nitrogenio - Fixação; Microorganismos fixadores de nitrogenio; Sugar-cane

The sugarcane is a highly extractive culture in nitrogen. Besides the high cost of nitrogen fertilizers, these have low agronomic performance causing major environmental impacts. An economical alternative and environmentally advantageous to reduce the use of nitrogen fertilizer would be to increase biological nitrogen fixation by inoculation with diazotrophic bacteria. In this context, the present study aimed to verify the effect of inoculant formed by diazotrophic bacteria associated with different N-fertilizer doses applied in two ways, in increasing the efficiency of nitrogen use, with possible increase in productivity sugarcane with reduced mineral N source. The field experiment was conducted in the city of Igaraçu do Tietê/SP during the crop season 2011/2012. The variety RB92579 was used in the first ratoon cycle in a production environment classified as A. The treatments consisted of different N doses (0, 60, 90 and 120 kg ha-1) associated or not with a mixed of five diazotrophic bacteria species (inoculant) in two inoculation methods (injected immediately after cutting the clumps and foliar application 60 days after cutting the clumps). The inoculum used was a strains mixed of five isolated bacteria species from sugarcane (Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae, Herbaspirillum rubrisubalbicans, Azospirillum amazonense e Burkholderia tropica). The Nitrogen doses were applied at 60 days after sprouting sugarcane ratoon. The experimental design was a randomized block in a 4x3 factorial scheme, constituted by nitrogen doses (N) and management of inoculation (M) totaling 12 treatments with four replicates. The number of failures and the nitrogen content in the leaves were determined at 120 days after initiation of shoots. At harvest physiological assessments (SPAD index and chlorophyll content), number of tillers, biometrics (length and diameter of stalk), technological analysis (theoretical recoverable sugar ...