Banca de DEFESA: RICARDO CESÁRIO DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RICARDO CESÁRIO DOS SANTOS
DATA : 08/08/2018
HORA: 09:00
LOCAL: Sala 01 PPGF
TÍTULO:

Plant growth promoting microorganisms, nitrification inhibitors and urease as a strategy to increase the efficiency of N fertilizer use in sorghum plants

PALAVRAS-CHAVES:

Azospirillum, nitrogen agronomic efficiency; Sorghum bicolor.

PÁGINAS: 45
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Fisiologia de Plantas Cultivadas
RESUMO:

The use of ammonia volatilization and nitrification inhibitors proved to be successful in reducing N losses after application of urea to crops, which in combination with seed inoculation with plant growth promoting bacteria (PGPB) would increase fertilization efficiency. This hypothesis was tested in this study. An experiment was carried out at the experimental station of Embrapa Agrobiologia, located in Seropédica, Rio de Janeiro. A randomized block design with 5 treatments and 5 replications was adopted. The treatments were different N fertilization strategies as follows: no N addition (T1); urea (120 kg N ha-1) (T2); urea (60 kg N ha-1) (T3); seed inoculation with Azospirillum brasilense ABV4 and ABV5 strains + urea (60 kg N ha-1) (T4); coated urea (60 kg N ha-1) with NBPT (T5); and coated urea (60 kg N ha-1) with NBPT + seed inoculation with A. brasilense ABV4 and ABV5 (T6). Each plot was 4 m long by 4 m wide, with 0.50 m interrow space. At seeding, plants were fertilized with 80 kg P2O5 ha-1 as single superphosphate, 40 kg K2O ha-1 as potassium chloride, and 3 kg micronutrients ha-1 as Cana Micros Plus®. Urea fertilization was split in two, with 20 kg N ha-1 at sowing and 40 kg N ha-1 as side-dressing. Grain yield and straw were quantified at harvesting. Results were submitted to ANOVA and significantly different means were separated by l.s.d. test at p<0.05. The use of nitrification inhibitor did not show statistical differences between treatments Urea (60 kg N ha-1) + DCD and pure urea (60 kg N ha-1) or pure urea (60 kg N ha-1) plus A. the treatment with urea + DCD + Azospirillum differed statistically from the treatment urea (60 kg N ha-1) + DCD with a 45% reduction in N2O emissions. Volatilization of ammonia in the absence of inhibitor was about 10% of the N added, regardless of the application dose, but when present, the inhibitor reduced N losses by half. There was no effect of seed inoculation on losses by volatilization. Grain production was affected by the use of Azospirillum and / or Azospirillum + Inhibitors with an increase of 1.7% and 7.7% in relation to treatment with pure urea (60 kg N ha-1), but it was not possible to observe differences between treatments. It was not possible to verify a synergy in the efficiency of the use of fertilizers when combining the technologies of inhibitors of volatilization and nitrification together with the inoculation of seeds with PGPB.

MEMBROS DA BANCA:
Presidente - 058.898.198-28 - SEGUNDO SACRAMENTO URQUIAGA CABALLERO - USP
Interno - 387256 - JORGE JACOB NETO
Externo à Instituição - MARCIO DOS REIS MARTINS - EMBRAPA