Seasonal and long-term effects of nutrient additions and liming on the nifH gene in cerrado soils under native vegetation

Rafaella Silveira; Thiago de Roure Bandeira de Mello; Maria Regina Silveira Sartori; Gabriel Sérgio Costa Alves; Fernando Campos de Assis Fonseca; Carla Simone Vizzotto; Ricardo Henrique Krüger; Mercedes Maria da Cunha Bustamante

doi:10.1016/j.isci.2021.102349

Seasonal and long-term effects of nutrient additions and liming on the nifH gene in cerrado soils under native vegetation

iScience. 2021 Mar 22;24(4):102349. doi: 10.1016/j.isci.2021.102349. eCollection 2021 Apr 23.

Authors

Rafaella Silveira¹, Thiago de Roure Bandeira de Mello², Maria Regina Silveira Sartori², Gabriel Sérgio Costa Alves¹, Fernando Campos de Assis Fonseca¹, Carla Simone Vizzotto¹, Ricardo Henrique Krüger¹, Mercedes Maria da Cunha Bustamante²

Affiliations

¹ Cell Biology Department, Institute of Biology, University of Brasília, Brasília, DF 70910-900, Brazil.
² Department of Ecology, Institute of Biology, University of Brasília, Brasília, DF 70910-900, Brazil.

Abstract

Biological nitrogen fixation (BNF) represents the main input source of N in tropical savannas. BNF could be particularly important for Brazilian savannas (known as Cerrado) that show a highly conservative N cycle. We evaluated the effects of seasonal precipitation and nutrient additions on the nifH gene abundance in soils from a long-term fertilization experiment in a Cerrado's native area. The experiment consists of five treatments: (1) control, (2) liming, (3) nitrogen (N), (4) nitrogen + phosphorus (NP), and (5) phosphorus (P) additions. The nifH gene sequence was related to Bradyrhizobium members. Seasonal effects on N-fixing potential were observed by a decrease in the nifH relative abundance from rainy to dry season in control, N, and NP treatments. A significant reduction in nifH abundance was found in the liming treatment in both seasons. The findings evidenced the multiple factors controlling the potential N-fixing by free-living diazotrophs in these nutrient-limited and seasonally dry ecosystems.

Keywords: Global Nutrient Cycle; Microbiology; Plant Ecology.