Premium
Soil organic matter content controls gross nitrogen dynamics and N 2 O production in riparian and upland boreal soil
Author(s) -
Figueiredo V.,
EnrichPrast A.,
Rütting T.
Publication year - 2016
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/ejss.12384
Subject(s) - nitrification , riparian zone , mineralization (soil science) , organic matter , soil water , taiga , soil organic matter , environmental science , nitrogen cycle , boreal , agronomy , environmental chemistry , nitrogen , chemistry , soil science , ecology , biology , organic chemistry , habitat
We investigated the pathways of gross soil nitrogen ( N ) transformations and nitrous oxide ( N 2 O ) production with 15 N enrichment techniques in a boreal forest landscape by comparing organic (riparian) and mineral (upland) soil within two catchments in northern S weden. The values of all soil properties evaluated for the riparin and upland zones were statistically different ( P < 0.05). The rates of gross N transformation were larger in the riparian than in the upland soil ( P < 0.05), which can be explained by the larger soil organic matter ( SOM ) content that provides energy and mineral N as a substrate for other processes. The riparian soil at one site shows a decoupling of nitrification from mineralization; the largest gross mineralization occurred in the soil at this site, but gross nitrification was relatively small. This was probably because of the low pH (2.7 ± 0.1), which inhibits the activity of autotrophic nitrifiers. Oxidation of organic N was the main source of N 2 O in the soil at all sites, probably because of low soil pH and large organic carbon content, which favours heterotrophic nitrification. The results of our study confirm that organic matter is the main regulating factor for gross N mineralization and nitrification; the latter are markedly different in the organic‐rich riparian soil and the upland soil in the boreal forest landscape. Highlights Which soil properties control gross N transformations and N 2 O production pathways in boreal soil? Examined nitrogen dynamics in two boreal forest soils with 15 N . Considerable oxidation of organic N in boreal soil is the main source of N 2 O . Soil organic matter is the main regulator of N transformations in boreal forest soil.