Laboratory measurements of soil microbial biomass and nitrogen mineralization from two Chinese soils as influenced by long-term applications of manure and inorganic fertilizers

The purpose of this study was to investigate the results of two long-term fertilization experiments on soil organic C, total N, and mineralizable N in the Jiangsu Province of People's Republic of China. The soil samples that received manure over the years contained more soil organic C, and total N than the inorganic fertilized samples. Soil organic C was closely correlated with total N and there were correlations between crop yields and soil organic C contents and between crop yields and soil total N contents. Plant-available N was estimated using biological and chemical tests. Mineralized N formed under anaerobic incubation was low except for those soil samples that received manure. Microbial biomass C and N were estimated using the chloroform fumigation-incubation method (CFIM) and fumigation-extraction procedures. Biomass measurements by CFIM were more precise and reliable than values obtained by fumigation-extraction. Treatment differences in biomass were not significant. Estimates of biomass C and N were influenced by the choice of the control soil and the period of incubation used by the CFIM. Unfumigated (10-20 d) control soils were found to be the best control for samples. Extraction of mineralized N using O.5M NaHCO$ sb3$ after incubation overestimated biomass N since this extraction was found to extract non-biomass N.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.68236
Date January 1994
CreatorsOuimet, Nicole
ContributorsMacKenzie, A. F. (advisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Department of Natural Resource Sciences.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001396233, proquestno: AAIMM94494, Theses scanned by UMI/ProQuest.

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