Forms of inoculation with growth promoting bacteria in the nutrition and agronomic performance of corn in the cerrado

Author(s)

Rafaela Neris Gaspareto

• Document type: Master's Dissertation
• Press: Ilha Solteira. 2018-09-13.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira
• Defense date: 2018-08-20
• Advisor: Marcelo Carvalho Minhoto Teixeira Filho

Abstract

Due to the high cost of nitrogen fertilizers and the awareness of a sustainable and less polluting agriculture, the use of inoculants containing diazotrophic bacteria has been increased, which besides propitiating the biological fixation of nitrogen (N) also has phytohormonal action, promoting thus, greater root system development, water and nutrient absorption, with positive effects on maize grain growth and yield. The objective was to evaluate the effect of the inoculation of maize grown in the crop and in the second crop, with six species of plant growth promoting bacteria, applied via seeds or in a directed jet at the base of the plant, always with 25% reduction in dose (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn), grain production and productivity components in the Cerrado region, as well as changes in nutrient uptake and soil chemical attributes in the 0-20 cm layer. The experiments were carried out in Selvíria - MS, in an RED OXISOL Dystrophic in no-tillage system with spacing of 0.45 m between rows. The experimental design in the two crops was in randomized blocks with four replicates, arranged in a factorial scheme 6 x 2 +3, being six inoculations with A. brasilense, B. amyloliquefaciens, B. licheniformis, B. pumilus, B. subtilis and P. fluorescens, applied by seed or in a directed spray at the base of the plant in the V3 stage of the corn, all of these treatments being 25% reduction in the N dose recommended in coverage; besides the control without inoculation and nitrogen fertilization; fertilization with the recommended N dose (150 kg ha-1 = 100%) under cover and without inoculation; and application of 75% of the dose of N (112.5 kg ha-1) recommended in coverage and without inoculation. Growth promoting bacteria and forms of inoculation interfere in the extraction and export of nutrients by the corn plant. The corn plants inoculated with B. licheniformis extracted higher amounts of nutrients (in kg t-1 of grains produced), especially when inoculated via a V3-directed jet. The results show that the N dose under the conditions tested can be reduced by 25% in the crop of the harvesting and second crop, when inoculated via seed or in a directed jet at the base of the plant in the V3 stage with some of the bacteria tested. In general, inoculation with B. licheniformis provided the highest corn grain yields. (AU)

• FAPESP's process: 17/03238-9 - Forms of inoculation with promoting bacteria of growth in nutrition and agronomic performance of corn in the Cerrado
• Grantee: Rafaela Neris Gaspareto
• Support Opportunities: Scholarships in Brazil - Master