CENTURY model simulation of soil C and N on a thin Black Chernozem
Date
1991-02-21
Authors
Greer, K.J.
Monreal, C.
Anderson, D.W.
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Presentation
Degree Level
Abstract
CENTURY is a process oriented soil organic matter (SOM) model, based on the conceptual division of SOM into active, slow, and passive phases. Carbon (C) and nitrogen (N) flow, from plant residue through the SOM
compartments, is driven by monthly precipitation and temperature and moderated by the nutrient content of the residue. CENTURY simulations of cultivated soils in the American Great Plains have agreed well with the changes in C and N observed over the last 100 years. However, use of this model to predict SOM in Saskatchewan soils, is limited by incomplete validation under our conditions. The thin Black Chernozemic soils of the Indian Head Experimental farm provide a unique opportunity to validate the CENTURY model, since both cropping history and soil C and N have been recorded for over 100 years. CENTURY predicted C and N levels (mass per unit area basis) within 4 to 21 % of those observed, after 26 years under fallow-wheat, fallow-wheat-wheat, continuous wheat and fallow-wheat-wheat-hay-hay-hay. Where soil erosion was not considered as a mechanism of SOM loss, CENTURY over-predicted C and N by 30 to 45 % of the observed. CENTURY prediction of mean annual C production as grain was 25 to 41% lower than the observed levels. Such yield functions, which consider the loss of available nutrients in the SOM as well as less residue returned to the system may be useful in estimating the long term direct costs of soil erosion on grain production.
Description
Keywords
Citation
Degree
Department
Program
Advisor
Committee
Part Of
Soils and Crops Workshop