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

Autor: Carla Simone Vizzotto, Mercedes M. C. Bustamante, Thiago de Roure Bandeira de Mello, Fernando Campos de Assis Fonseca, Ricardo Henrique Krüger, Maria Regina Silveira Sartori, Gabriel Sergio Costa Alves, Rafaella Silveira
Rok vydání: 2020
Předmět:
Zdroj: iScience
iScience, Vol 24, Iss 4, Pp 102349-(2021)
ISSN: 2589-0042
Popis: Summary 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.
Graphical abstract
Highlights • First assessment of nutrient addition effects on nifH gene abundance in Cerrado soils • Increases in soil pH and nutrient contents negatively affected nifH gene abundance • nifH gene relative abundance was positively affected by precipitation's seasonality • Reduction in potential BNF suggests that eutrophication can induce long-term changes
Microbiology; Plant Ecology; Global Nutrient Cycle
Databáze: OpenAIRE