Abstract

The application of inorganic nitrogen (N) fertilizers strongly influences the contribution of agriculture to the greenhouse effect, especially by potentially increasing emissions of nitrous oxide (N(2)O), carbon dioxide (CO(2)) and methane (CH(4)) from soils. The present microcosm-study investigates the effect of different forms of inorganic N fertilizers on greenhouse gas (GHG) emissions from two different agricultural soils. The relationship between greenhouse gas emissions and soil microbial communities, N transformation rates and plant (Hordeum vulgare L. cv. Morex) growth were investigated. Repeated N fertilization led to increased N(2)O emissions. In a parallel survey of functional microbial population dynamics we observed a stimulation of bacterial and archaeal ammonia oxidisers accompanied with these N(2)O emissions. The ratio of archaeal to bacterial ammonium monooxygenase subunit A (amoA) gene copies (data obtained from Inselsbacher et al., 2010) correlated positively with N(2)O fluxes, which suggests a direct or indirect involvement of archaea in N(2)O fluxes. Repeated N fertilization also stimulated methane oxidation, which may also be related to a stimulation of ammonia oxidizers. The fertilizer effects differed between soil types: In the more organic Niederschleinz soil N-turnover rates increased more strongly after fertilization, while in the sandy Purkersdorf soil plant growth and soil respiration were accelerated depending on fertilizer N type. Compared to addition of NH (4) (+) and NO (3) (-) , addition of NH(4)NO(3) fertilizer resulted in the largest increase in global warming potential as a summary indicator of all GHG related effects. This effect resulted from the strongest increase of both N(2)O and CO(2) emission while plant growth was not equally stimulated, compared to e.g. KNO(3) fertilization. In order to decrease N losses from agricultural ecosystems and in order to minimize soil derived global warming potential, this study points to the need for interdisciplinary investigations of the highly complex interactions within plant-soil-microbe-atmosphere systems. By understanding the microbial processes underlying fertilizer effects on GHG emissions the N use efficiency of crops could be refined.

Keywords

Nitrous oxide; Carbon dioxide; Methane; Greenhouse gases; Agricultural soil; N fertilizer; Microbial community structure

Published in

Plant and Soil
2011, Volume: 343, number: 1-2, pages: 17-35
Publisher: Springer Verlag (Germany)

SLU Authors

• Inselsbacher, Erich

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    
  • Federal Research and Training Centre for Forests, Natural Hazards and Landscape
  • University of Vienna

Sustainable Development Goals

SDG15 Life on land


UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication Identifiers

DOI: https://doi.org/10.1007/s11104-010-0597-6

Permanent link to this page (URI)

https://res.slu.se/id/publ/35951