Dynamics of ammonia exchange with cut grassland: strategy and implementation of the GRAMINAE Integrated Experiment

Abstract

Abstract. A major international experiment on ammonia (NH3) biosphere-atmosphere exchange was conducted over intensively managed grassland at Braunschweig, Germany. The experimental strategy was developed to allow an integrated analysis of different features of NH3 exchange including: a) quantification of nearby emissions and advection effects, b) estimation of net NH3 fluxes with the canopy by a range of micrometeorological measurements, c) analysis of the sources and sinks of NH3 within the plant canopy, including soils and bioassay measurements, d) comparison of the effects of grassland management options on NH3 fluxes and e) assessment of the interactions of NH3 fluxes with aerosol exchange processes. Additional technical objectives included the inter-comparison of different estimates of sensible and latent heat fluxes, as well as continuous-gradient and Relaxed Eddy Accumulation (REA) systems for NH3 fluxes. The prior analysis established the spatial and temporal design of the experiment, allowing significant synergy between these objectives. The measurements were made at 7 measurement locations, thereby quantifying horizontal and vertical profiles, and covered three phases: a) tall grass canopy prior to cutting (7 days), b) short grass after cutting (7 days) and c) re-growing sward following fertilization with ammonium nitrate (10 days). The sequential management treatments allowed comparison of sources-sinks, advection and aerosol interactions under a wide range of NH3 fluxes. This paper describes the experimental strategy and reports the grassland management history, soils, environmental conditions and air chemistry during the experiment, finally summarizing how the results are coordinated in the accompanying series of papers.

Intercomparison and assessment of turbulent and physiological exchange parameters of grassland

“…In the SW corner of the field was the enclosure of the German Weather Service (DWD), which consisted of a patchwork of small grass plots with varying roughness height and water status. The participating research groups and the abbreviations used for each have been presented elsewhere, together with further details on the field site (surroundings, as well as position of scaffolding towers and mobile laboratory) and site management Sutton et al, 2009b).…”

“…The main aim of the overall experiment was to investigate the dynamics of ammonia exchange between agricultural grassland and the atmosphere, as described in detail elsewhere (Sutton et al, 2009b).…”

Vertical structure and diurnal variability of ammonia exchange potential within an intensively managed grass canopy

“…The experiment presented here was carried out in May and June 2000 in Braunschweig, Germany and was part of a joint investigation within the EU GRAMINAE project (for a detailed description of the experiment see Sutton et al, 2008). The aim was to estimate the NH 3 exchange potential of the vegetation on a vertical gradient within a fertilized grass canopy and its diurnal variations by means of χ s measurements.…”

Metrology for ammonia in ambient air – concept and first results of the EMRP project MetNH3

“…Measuring Ammonia in Nature (MAN) Network in the Netherlands, and the National Ammonia Monitoring Network (NAN) in the UK) provide additional data to assess ambient ammonia concentrations and trends. Besides these long-term monitoring activities with lower temporal and spatial resolution, shorter measurement campaigns with higher temporal resolution are organized as well to address specific questions [1,8,9]. Countries currently adopt a variety of approaches; there is no European standard for ammonia monitoring.…”