Nitrogen Dynamics in Hydrological Flow Paths of a Small Tropical Pasture Catchment

Author(s)

Salemi, Luiz Felippe ^[1] ; Groppo, Juliano Daniel ^[1] ; Trevisan, Rodrigo ^[1] ; de Barros Ferraz, Silvio Frosini ^[2] ; de Moraes, Jorge Marcos ^{[3, 1]} ; Martinelli, Luiz Antonio ^[1]

Affiliation

^[1] Univ Sao Paulo, Lab Ecol Isotop, Ctr Energia Nucl Agr, Piracicaba, SP - Brazil

^[2] Univ Sao Paulo, Lab Hidrol Florestal, Escola Super Agr Luiz de Queiroz, Piracicaba, SP - Brazil

^[3] Escola Engn Piracicaba, Piracicaba, SP - Brazil

• Document type: Journal article
• Source: CATENA; v. 127, p. 250-257, APR 2015.
• Web of Science Citations: 5

Abstract

In this paper we report nitrogen (N) dynamics within hydrological flow paths of a small tropical pasture catchment within the Atlantic Rainforest region in Natividade da Serra, Sao Paulo State, Brazil. By collecting soil solution through 27 tension lysimeters, surface runoff through 9 plots, groundwater through one well and one stream over the course of a year, N species concentration and fluxes could be clarified. All hydrological flow paths were dominated by organic N (similar to 60-85%). This finding is explained as a consequence of a drop of soil N cycling rates and N gaseous fluxes previously reported in the literature. Nitrogen input via bulk precipitation (similar to 3.5 kg N ha(-1) year(-1)) exceeded N hydrological output through stream water (similar to 2 kg N ha(-1) year(-1)). Similar findings have been described for pastures of the Brazilian Amazon Basin. If pastures like these are maintained without fertilization, catchments whose land use is old pastures may not be an important direct source of inorganic N for downstream regions. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 06/54292-9 - Study of the hydric balance and the biogeochemical balance of nitrogen in a first order microbasin with pasture cover on the north coast of the State of São Paulo
• Grantee: Luiz Felippe Salemi
• Support Opportunities: Scholarships in Brazil - Master