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Title: A Mechanistic Treatment of the Dominant Soil Nitrogen Cycling Processes: Model Development, Testing, and Application

Abstract

The development and initial application of a mechanistic model (TOUGHREACT-N) designed to characterize soil nitrogen (N) cycling and losses are described. The model couples advective and diffusive nutrient transport, multiple microbial biomass dynamics, and equilibrium and kinetic chemical reactions. TOUGHREACT-N was calibrated and tested against field measurements to assess pathways of N loss as either gas emission or solute leachate following fertilization and irrigation in a Central Valley, California, agricultural field as functions of fertilizer application rate and depth, and irrigation water volume. Our results, relative to the period before plants emerge, show that an increase in fertilizer rate produced a nonlinear response in terms of N losses. An increase of irrigation volume produced NO{sub 2}{sup -} and NO{sub 3}{sup -} leaching, whereas an increase in fertilization depth mainly increased leaching of all N solutes. In addition, nitrifying bacteria largely increased in mass with increasing fertilizer rate. Increases in water application caused nitrifiers and denitrifiers to decrease and increase their mass, respectively, while nitrifiers and denitrifiers reversed their spatial stratification when fertilizer was applied below 15 cm depth. Coupling aqueous advection and diffusion, and gaseous diffusion with biological processes, closely captured actual conditions and, in the system explored here, significantlymore » clarified interpretation of field measurements.« less

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
Earth Sciences Division
OSTI Identifier:
934775
Report Number(s):
LBNL-486E
TRN: US200814%%482
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research-Biogeosciences
Additional Journal Information:
Journal Volume: 113; Journal Issue: G02016, doi:10.1029/2007JG000578; Related Information: Journal Publication Date: 2008
Country of Publication:
United States
Language:
English
Subject:
54; 58; ADVECTION; BACTERIA; BIOMASS; CHEMICAL REACTIONS; DIFFUSION; FERTILIZATION; FERTILIZERS; GASEOUS DIFFUSION; IRRIGATION; KINETICS; LEACHATES; LEACHING; NITROGEN; NUTRIENTS; SOILS; SOLUTES; STRATIFICATION; TESTING

Citation Formats

Riley, William, Maggi, F, Gu, C, Riley, W J, Hornberger, G M, Venterea, R T, Xu, T, Spycher, N, Steefel, C, Miller, N L, and Oldenburg, C M. A Mechanistic Treatment of the Dominant Soil Nitrogen Cycling Processes: Model Development, Testing, and Application. United States: N. p., 2008. Web.
Riley, William, Maggi, F, Gu, C, Riley, W J, Hornberger, G M, Venterea, R T, Xu, T, Spycher, N, Steefel, C, Miller, N L, & Oldenburg, C M. A Mechanistic Treatment of the Dominant Soil Nitrogen Cycling Processes: Model Development, Testing, and Application. United States.
Riley, William, Maggi, F, Gu, C, Riley, W J, Hornberger, G M, Venterea, R T, Xu, T, Spycher, N, Steefel, C, Miller, N L, and Oldenburg, C M. Thu . "A Mechanistic Treatment of the Dominant Soil Nitrogen Cycling Processes: Model Development, Testing, and Application". United States. https://www.osti.gov/servlets/purl/934775.
@article{osti_934775,
title = {A Mechanistic Treatment of the Dominant Soil Nitrogen Cycling Processes: Model Development, Testing, and Application},
author = {Riley, William and Maggi, F and Gu, C and Riley, W J and Hornberger, G M and Venterea, R T and Xu, T and Spycher, N and Steefel, C and Miller, N L and Oldenburg, C M},
abstractNote = {The development and initial application of a mechanistic model (TOUGHREACT-N) designed to characterize soil nitrogen (N) cycling and losses are described. The model couples advective and diffusive nutrient transport, multiple microbial biomass dynamics, and equilibrium and kinetic chemical reactions. TOUGHREACT-N was calibrated and tested against field measurements to assess pathways of N loss as either gas emission or solute leachate following fertilization and irrigation in a Central Valley, California, agricultural field as functions of fertilizer application rate and depth, and irrigation water volume. Our results, relative to the period before plants emerge, show that an increase in fertilizer rate produced a nonlinear response in terms of N losses. An increase of irrigation volume produced NO{sub 2}{sup -} and NO{sub 3}{sup -} leaching, whereas an increase in fertilization depth mainly increased leaching of all N solutes. In addition, nitrifying bacteria largely increased in mass with increasing fertilizer rate. Increases in water application caused nitrifiers and denitrifiers to decrease and increase their mass, respectively, while nitrifiers and denitrifiers reversed their spatial stratification when fertilizer was applied below 15 cm depth. Coupling aqueous advection and diffusion, and gaseous diffusion with biological processes, closely captured actual conditions and, in the system explored here, significantly clarified interpretation of field measurements.},
doi = {},
journal = {Journal of Geophysical Research-Biogeosciences},
number = G02016, doi:10.1029/2007JG000578,
volume = 113,
place = {United States},
year = {2008},
month = {5}
}