Plant and Soil

, Volume 352, Issue 1–2, pp 289–301

Soil moisture effects on gross nitrification differ between adjacent grassland and forested soils in central Alberta, Canada

Regular Article

DOI: 10.1007/s11104-011-0997-2

Cite this article as:
Cheng, Y., Cai, Z., Zhang, J. et al. Plant Soil (2012) 352: 289. doi:10.1007/s11104-011-0997-2

Abstract

Background and aims

Changes in soil moisture availability seasonally and as a result of climatic variability would influence soil nitrogen (N) cycling in different land use systems. This study aimed to understand mechanisms of soil moisture availability on gross N transformation rates.

Methods

A laboratory incubation experiment was conducted to evaluate the effects of soil moisture content (65 vs. 100% water holding capacity, WHC) on gross N transformation rates using the 15N tracing technique (calculated by the numerical model FLUAZ) in adjacent grassland and forest soils in central Alberta, Canada.

Results

Gross N mineralization and gross NH4+ immobilization rates were not influenced by soil moisture content for both soils. Gross nitrification rates were greater at 100 than at 65% WHC only in the forest soil. Denitrification rates during the 9 days of incubation were 2.47 and 4.91 mg N kg-1 soil d-1 in the grassland and forest soils, respectively, at 100% WHC, but were not different from zero at 65% WHC. In the forest soil, both the ratio of gross nitrification to gross NH4+ immobilization rates (N/IA) and cumulative N2O emission were lower in the 65 than in the 100% WHC treatment, while in the grassland soil, the N/IA ratio was similar between the two soil moisture content treatments but cumulative N2O emission was lower at 65% WHC.

Conclusions

The effect of soil moisture content on gross nitrification rates differ between forest and grassland soils and decreasing soil moisture content from 100 to 65% WHC reduced N2O emissions in both soils.

Keywords

15N tracing technique FLUAZ Gross N mineralization Gross nitrification Soil moisture content Denitrification 

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil ScienceChinese Academy of SciencesNanjingChina
  2. 2.Department of Renewable ResourcesUniversity of AlbertaEdmontonCanada
  3. 3.College of Applied MeteorologyNanjing University of Information Science & TechnologyNanjingChina
  4. 4.INRA, Unit Agro-ImpactBarenton-BugnyFrance

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