Nitrogen fertilization and co-inoculation with growth-promoting bacteria in wheat crops in the Cerrado region

• Grant number: 25/13622-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Marcelo Carvalho Minhoto Teixeira Filho
• Grantee: Anthony Martins Gomes
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil
• Associated research grant: 24/00819-4 - Nitrogen doses (15N) and co-inoculation with growth-promoting bacteria in the wheat-soybean system in the Cerrado region: Nitrogen recovery from fertilizer and biological nitrogen fixation, AP.R

Abstract

, the use of wheat cultivars with high production potential combined with technologies that promote greater resilience in production systems and are committed to the Sustainable Development Goals (SDGs) is fundamental to the success of modern agriculture. Research has demonstrated the potential of using plant growth-promoting bacteria (PGPBs) to improve plant development by acting on various mechanisms related to growth promotion, particularly nutrient availability, uptake, and use efficiency in production systems. However, knowledge about the developmental response, production components, and productivity of grasses associated with the use of more than one PGPB combined with nitrogen fertilization is insufficient and deserves further study under specific environmental conditions, such as in Cerrado regions. In this regard, the assumption is that the combined inoculation of two PGPBs, via seeds, associated with N doses, promotes additive effects of individual benefits, optimizing BNF and nutrient use efficiency. This positively impacts plant nutrition, vegetative and productive performance, and reduces the need for fertilizers in irrigated wheat cultivation. Therefore, this research aims to evaluate the effects of seed inoculation with Azospirillum brasilense applied alone and in combination with Bacillus subtilis or Pseudomonas fluorescens in wheat combined with N rates on nutrition, development, grain yield, nutrient accumulation, and nitrogen use efficiency (NUE) of irrigated wheat. The experiment will be conducted with irrigated wheat, in an experimental area of ¿¿the Ilha Solteira School of Engineering, UNESP, Selvíria-MS, on a dystroferric Red Latosol, Cerrado phase, under a consolidated no-tillage system (> 15 years of adoption). The experimental design will be a randomized complete block design, in a 4x5 factorial arrangement, with four replicates. The treatments will consist of three inoculations plus a control without inoculation: 1) Azospirillum brasilense; 2) A. brasilense + Pseudomonas fluorescens; 3) A. brasilense + Bacillus subtilis and 4) Control, combined with five N rates: 0, 30, 60, 120, and 180 kg ha-1 applied as topdressing in the form of urea. Soil and plant chemical analyses will be performed at UNESP laboratories. Wheat nutritional status at flowering will be analyzed; biometric growth assessments; production components; grain yield; extraction (whole plant), export (grains), and return of macro and micronutrients to the soil (straw - crop residues).