Impact of nitrogen fertilizer sustainability on corn crop yield: the role of beneficial microbial inoculation interactions

Fernando Shintate Galindo; Paulo Humberto Pagliari; Edson Cabral da Silva; Bruno Horschut de Lima; Guilherme Carlos Fernandes; Cassio Carlette Thiengo; João Victor Silva Bernardes; Arshad Jalal; Carlos Eduardo Silva Oliveira; Lucila de Sousa Vilela; Enes Furlani Junior; Thiago Assis Rodrigues Nogueira; Vagner do Nascimento; Marcelo Carvalho Minhoto Teixeira Filho; José Lavres

doi:10.1186/s12870-024-04971-3

Impact of nitrogen fertilizer sustainability on corn crop yield: the role of beneficial microbial inoculation interactions

BMC Plant Biol. 2024 Apr 11;24(1):268. doi: 10.1186/s12870-024-04971-3.

Authors

Fernando Shintate Galindo¹, Paulo Humberto Pagliari², Edson Cabral da Silva³, Bruno Horschut de Lima³, Guilherme Carlos Fernandes³, Cassio Carlette Thiengo⁴, João Victor Silva Bernardes⁴, Arshad Jalal⁵, Carlos Eduardo Silva Oliveira³, Lucila de Sousa Vilela⁶, Enes Furlani Junior³, Thiago Assis Rodrigues Nogueira⁷, Vagner do Nascimento⁶, Marcelo Carvalho Minhoto Teixeira Filho³, José Lavres⁴

Affiliations

¹ College of Agricultural and Technological Sciences, Department of Crop Production, São Paulo State University, Dracena, 17900-000, Brazil. fernando.galindo@unesp.br.
² Southwest Research and Outreach Center, Department of Soil, Water, and Climate, University of Minnesota, Lamberton, MN, 56152, USA.
³ Department of Plant Health, Rural Engineering, and Soils, São Paulo State University, Ilha Solteira, 15345-000, Brazil.
⁴ Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, 13416-000, Brazil.
⁵ King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia.
⁶ College of Agricultural and Technological Sciences, Department of Crop Production, São Paulo State University, Dracena, 17900-000, Brazil.
⁷ Department of Agricultural Sciences, São Paulo State University, Jaboticabal, 14884-900, Brazil.

Abstract

Background: Considering the challenges posed by nitrogen (N) pollution and its impact on food security and sustainability, it is crucial to develop management techniques that optimize N fertilization in croplands. Our research intended to explore the potential benefits of co-inoculation with Azospirillum brasilense and Bacillus subtilis combined with N application rates on corn plants. The study focused on evaluating corn photosynthesis-related parameters, oxidative stress assay, and physiological nutrient use parameters. Focus was placed on the eventual improved capacity of plants to recover N from applied fertilizers (AFR) and enhance N use efficiency (NUE) during photosynthesis. The two-year field trial involved four seed inoculation treatments (control, A. brasilense, B. subtilis, and A. brasilense + B. subtilis) and five N application rates (0 to 240 kg N ha^-1, applied as side-dress).

Results: Our results suggested that the combined effects of microbial consortia and adequate N-application rates played a crucial role in N-recovery; enhanced NUE; increased N accumulation, leaf chlorophyll index (LCI), and shoot and root growth; consequently improving corn grain yield. The integration of inoculation and adequate N rates upregulated CO₂ uptake and assimilation, transpiration, and water use efficiency, while downregulated oxidative stress.

Conclusions: The results indicated that the optimum N application rate could be reduced from 240 to 175 kg N ha^-1 while increasing corn yield by 5.2%. Furthermore, our findings suggest that replacing 240 by 175 kg N ha^-1 of N fertilizer (-65 kg N ha^-1) with microbial consortia would reduce CO₂ emission by 682.5 kg CO₂ ^-e ha^-1. Excessive N application, mainly with the presence of beneficial bacteria, can disrupt N-balance in the plant, alter soil and bacteria levels, and ultimately affect plant growth and yield. Hence, highlighting the importance of adequate N management to maximize the benefits of inoculation in agriculture and to counteract N loss from agricultural systems intensification.

Keywords: Azospirillum brasilense; Bacillus subtilis; Biotic stress; N synergists; N use efficiency and recovery.

MeSH terms

Agriculture
Carbon Dioxide
Fertilizers*
Nitrogen / analysis
Soil
Zea mays*

Substances

Fertilizers
Nitrogen
Carbon Dioxide
Soil

Abstract

MeSH terms

Substances

Grants and funding