The potential of soils from cropland and varying riparian buffer vegetations to emit NO, N2O, N2, and CO2 under denitrification.

Abstract

Abstract Riparian buffers are expedient interventions for water quality functions in agricultural landscapes. However, the choice of their vegetation and management affects soil microbial communities, which in turn affect nutrient cycling and the production and emission of gases such as nitric oxide (NO), nitrous oxide (N2O), nitrogen gas (N2), and carbon dioxide (CO2). To investigate the potential fluxes of the above-mentioned gases, soil samples were collected from a cropland and downslope grass, willow, and woodland riparian buffers from a replicated plot scale experimental facility. The soils were re-packed into cores, and to investigate their potential to produce the aforementioned gases, a potassium nitrate (KNO3−) and glucose (labile carbon)-containing amendment, was added prior to incubation in a specialized laboratory DENItrification System (DENIS). The resulting NO, N2O, N2, and CO2 emissions were measured simultaneously, with the highest NO (2.9 ± 0.31 mg NO m− 2), and N2O (1413.4 ± 448.3 mg N2O m− 2) generated by the grass riparian buffer and the highest N2 (698.1 ± 270.3 mg N2 m− 2) and CO2 (27558.3 ± 128.9 mg CO2 m− 2) produced by the willow riparian buffer. Thus, the results show that soils developed under grass and willow riparian buffers may potentially increase greenhouse gas fluxes, especially in areas with similar conditions to the current study.