HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hadas, A. Articles by Clapp, C. E. Search for Related Content PubMed Articles by Hadas, A. Articles by Clapp, C. E. Agricola Articles by Hadas, A. Articles by Clapp, C. E.

Simulation of Nitrogen-15 Immobilization by the Model NCSOIL¹

ABSTRACT

The computer model NCSOIL computes the dynamics of C and N transformations in soil. In its original version, the microbial biomass assimilated organic N from the decay of organic pools, and inorganic N was immobilized only when decomposed organics were deficient in N with respect to biomass needs for growth (NCSOIL—direct version). A new version was presented in which it was assumed that microbial biomass immobilized N only from the inorganic pool, while the decay of organic N always resulted in N mineralization (NCSOIL-MIT version). NCSOIL-MIT was calibrated and tested for the incorporation of inorganic ¹⁵N in the organic soil N against experimental data and compared with the direct version. Net N mineralization was highly sensitive to the microbial efficiency of soil decomposable organic C incorporation. An efficiency of 0.2 gave a good account of net N mineralization for soils unamended with organic substances. NCSOIL-MIT simulated the incorporation of ¹⁵N, added as NH₄, into the organic soil pools. The kinetics of ¹⁵N immobilization was sensitive to microbial efficiency as well as to other parameters that control soil N turnover. NCSOIL—direct version required the decomposition of polysaccharide-like material in order to obtain ¹⁵N incorporation in the soil organic pools, and the kinetics of ¹⁵N immobilization depended on the rate of polysaccharide decomposition.

¹ Contribution from the Dep. of Soil Science, Univ. of Minnesota, the Soil and Water Management Res. Unit, Northern States Area, USDA-ARS, St. Paul, MN 55108, and the ARO, The Volcani Center, Bet Dagan, 50250, Israel. Minnesota Agr. Exp. Stn., Scientific Journal Series Paper no. 14813.

² Soil Scientist, ARO; Professor of Soil Microbiology, Univ. of Minn.; Soil Scientist, ARO; Research Chemist, USDA-ARS, and Professor, Univ. of Minn.; respectively. Request for reprints and inquiries should be sent to J.A.E. Molina, Dep. of Soil Science, Univ. of Minnesota, St. Paul, MN 55108.

Received for publication February 28, 1986.

This article has been cited by other articles:

				J. D. Jabro, A. D. Jabro, and R. H. Fox Accuracy and Performance of Three Water Quality Models for Simulating Nitrate Nitrogen Losses under Corn. J. Environ. Qual., July 1, 2006; 35(4): 1227 - 1236. [Abstract] [Full Text] [PDF]