Transformations of Nitrogen at the Interface between the Topsoil and an Impervious Clay Subsoil
Autor: | D. J. Hatch, C. O'Prey, Philip J. Murray, R. J. Laughlin, R. J. Stevens, S. C. Jarvis, Steven J. Granger, Elizabeth Dixon |
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Rok vydání: | 2004 |
Předmět: |
Topsoil
Denitrification 15N Nitrous Oxide Soil science Mineralization (soil science) Nitrate Pollution chemistry.chemical_compound chemistry subsoil Soil water Leaching (pedology) Leaching Impervious surface Urea Environmental science General Earth and Planetary Sciences nitrite Subsoil Ammonium Earth-Surface Processes Water Science and Technology |
Zdroj: | Water, Air, & Soil Pollution: Focus. 4:45-52 |
ISSN: | 1573-2940 1567-7230 |
Popis: | Much work has been done on gaseous emissions and leaching of nitrogenous compounds from whole soil profiles and also from soil surface measurements which are assumed to be mainly due to topsoil activity. In soils with an impervious clay subsoil, the boundary between the topsoil and subsoil may provide an interface for microbial activity, including N transformations. In this study, we investigated movement and transformations of two reactive N species (nitrate and urea) at the subsoil interface using a series of replicate, intact soil blocks, under two contrasting watering regimes. We measured fluxes in both liquid and gaseous phases and demonstrated that nitrate reaching the subsoil interface does not necessarily leach into water systems, but may denitrify immediately and could, therefore, add to atmospheric pollution through N2O production. On the other hand, ammonium reaching the subsoil interface either directly, or after mineralization, appears to be more mobile than expected and has the potential to pollute watercourses. |
Databáze: | OpenAIRE |
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