Banca de DEFESA: LEONARDO FERREIRA RODRIGUES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LEONARDO FERREIRA RODRIGUES
DATE: 27/02/2026
TIME: 13:00
LOCAL: Virtual - Gmeet meet.google.com/svh-pngg-ndx
TITLE:

Ammonia volatilization from nitrogen fertilizers and possibilities for mitigation in Brazilian agriculture

KEY WORDS:

Nitrogen fertilizers; Urea; Meta-analysis; Ammonia; Greenhouse gases.

PAGES: 41
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Fertilidade do Solo e Adubação
SUMMARY:

Ammonia (NH₃) volatilization is one of the main processes responsible for nitrogen (N) losses in agricultural systems, reducing fertilizer efficiency and contributing to environmental impacts such as indirect greenhouse gas emissions. The objective of this dissertation was to quantify N losses by NH₃ volatilization from different nitrogen fertilizers and to compare the observed emission factors (EF) with the reference values proposed by the Intergovernmental Panel on Climate Change (IPCC, 2019). A systematic literature review was conducted, followed by a meta-analysis using data extracted from 61 eligible scientific articles, totaling 315 field observations from studies conducted in Brazil. Mean N–NH₃ volatilization values were calculated by simple average and by the inverse-variance weighting method, using a random-effects model in R software. The emission factor obtained by the inverse-variance method was 16.0 %, considered the most representative because it incorporates weighting related to variability and sample size, and it was within the 95 % confidence interval (CI95 %). This value was higher than the 14.2 % emission factor proposed by IPCC (2019) for urea under tropical conditions. Urea treated with the urease inhibitor NBPT reduced losses by up to 34 %, while controlled-release urea and those treated with multiple strategies showed intermediate reductions. Alternative sources, especially nitric, nitric-ammoniacal, and ammoniacal fertilizers, showed EFs below 2 %, indicating lower susceptibility to volatilization. Regression analyses revealed significant relationships between EF and soil attributes such as base sum, cation-exchange capacity (CEC), and temperature, highlighting the influence of edaphoclimatic conditions on N losses. The results demonstrate that the use of stabilized and non-amide fertilizers can reduce volatilization and increase nitrogen use efficiency, contributing to more productive and sustainable agricultural systems, while providing support for improving emission factors used in national greenhouse-gas inventories.

COMMITTEE MEMBERS:
Presidente - ***.282.827-** - BRUNO JOSÉ RODRIGUES ALVES - EMBRAPA
Interno - 2213075 - EVERALDO ZONTA
Externo à Instituição - CAIO DE TEVES INÁCIO - EMBRAPA