NCSOIL, A Model of Nitrogen and Carbon Transformations in Soil: Description, Calibration, and Behavior

Abstract

NCSOIL is a submodel of a larger program NTRM (nitrogen‐tillage‐residue management). NCSOIL computes short‐term dynamics of carbon and nitrogen organics, ammonium, and nitrate which result from the processes of residue decomposition, mineralization, immobilization, nitrification, and denitrification. Both total and isotopic nitrogen are considered. NCSOIL is built on the concept of catenary sequence of heterogenous substrates. The active soil organic phase is divided in two pools which are dynamic, defined by their kinetic rate constants and their position in the model structure. Residues are defined in terms of their chemical or morphological nature. A double feedback loop in the carbon flow adjusts the rate of residue decomposition and the efficiency factor to the availability of inorganic nitrogen. NCSOIL was calibrated with, and its behavior contrasted against published and unpublished data from an experiment reported by Chichester et al. in Soil Science (see p. 455, vol. 120): “Relative Mineralization Rates of Indigenous and Recently Incorporated 15‐N labeled Nitrogen.” Experimental results of the Chichester et al. experiment were discussed in view of computer‐simulated flow rates and substrate concentrations.

Management practices amplify the effects of N deposition on leaf litter decomposition of the Moso bamboo forest

“…In the early stage, N addition may increase the decomposers' activity (Molina et al 1983;Madritch and Hunter 2003) and promote N release. However, in the later stage, the cumulative N addition effect tends to induce C-based limitation of microbial decomposer activity (Thirukkumaran and Parkinson 2000;Andersson et al 2004), limiting N release.…”

The Role of Respiration in Estimation of Net Carbon Cycle: Coupling Soil Carbon Dynamics and Canopy Turnover in a Novel Version of 3D-CMCC Forest Ecosystem Model

“…tree age) scalars [43]. Autotrophic respiration (RA) was explicitly modeled as the sum of growth and maintenance respiration (RG and RM, respectively).…”

La modélisation hydrologique et la gestion de l'eau

“…Early modeiing efforts involved the coupling of first-order kinetics models for the nitrogen cycle (MEHRAN and TANJI, 1974) with two types of mass conservation équation in porous média: the convection-dispersion équation and the capacity transport équation. Well known soil nitrogen dynamics models include NCSOIL (MOLINA et al, 1983), SOILN (JOHNSSON et al, 1987), EPIC (SHARPLEV and WILLIAMS, 1990), LEA-CHN and LEACHA (HUTSON and WAGENET, 1991, DAISY (HAN-SEN et al, 1991) and AgriFlux (BANTON et al, 1993).…”

“…Plusieurs chercheurs, dont MOLINA et al (1983) Dans fes cas où l'écoulement de l'eau du sol est en régime transitoire selon la direction verticale (z), le cas généralement simulé, le lessivage des nitrates ou de l'ammonium est abordé soit par des lois de vidange de réservoirs (ex. : HUTSON et WAGENET, 1992BANTON et ai, 1993) soit par la résolution analytique ou numérique des équations de RICHARDS (1931) et de convection-dîspersion unidimensionnelles (HUTSON et WAGENET, 1991 ;BERGSTRÔM et ai, 1991).…”