Open AccessNitrogen fixation by free‐living microorganisms in the soil of a mature oak‐stand in Uppland, Sweden
Author(s) -
Nohrstedt HansÖrjan
Publication year - 1982
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/j.1600-0587.1982.tb01013.x
Subject(s) - nitrogenase , nitrogen fixation , microorganism , nitrogen , ecology , agronomy , seasonality , environmental science , growing season , botany , biology , chemistry , bacteria , organic chemistry , genetics
The nitrogenase activity of free‐living microorganisms was investigated in a brown forest soil beneath a mature oak‐Stand outside Uppsala, Central Sweden. The effect of season, air temperature, soil depth and some soil parameters on nitrogenase activity was studied. Only heterotrophic nitrogenase activity was detected. The main activity occurred in the upper 5 cm of the soil profile. The amount of nitrogen fixed during the growth season was calculated to 0.73 kg ha −1 . There was a strong seasonal variation of the nitrogenase activity with the highest level in July, August and September. The activity, when the soil was incubated at 25°C, was significantly correlated with the mean air temperature at the field site.