scholarly journals Season-long ammonia flux measurements above fertilized corn in central Illinois, USA, using relaxed eddy accumulation

2017 ◽  
Vol 239 ◽  
pp. 202-212 ◽  
Author(s):  
Andrew J. Nelson ◽  
Sotiria Koloutsou-Vakakis ◽  
Mark J. Rood ◽  
LaToya Myles ◽  
Christopher Lehmann ◽  
...  
Keyword(s):  
Relaxed Eddy Accumulation ◽  
Flux Measurements ◽  
Central Illinois ◽  
Ammonia Flux

Ammonia flux measurements above a corn canopy using relaxed eddy accumulation and a flux gradient system

2019 ◽  
Vol 264 ◽  
pp. 104-113 ◽  
Author(s):  
Andrew J. Nelson ◽  
Nebila Lichiheb ◽  
Sotiria Koloutsou-Vakakis ◽  
Mark J. Rood ◽  
Mark Heuer ◽  
...  
Keyword(s):  
Gradient System ◽  
Flux Gradient ◽  
Relaxed Eddy Accumulation ◽  
Flux Measurements ◽  
Ammonia Flux ◽  
Corn Canopy

Accuracy of the relaxed eddy-accumulation technique, evaluated using CO2 flux measurements

1993 ◽  
Vol 66 (4) ◽  
pp. 341-355 ◽  
Author(s):  
E. Pattey ◽  
R. L. Desjardins ◽  
P. Rochette
Keyword(s):  
Co2 Flux ◽  
Relaxed Eddy Accumulation ◽  
Flux Measurements

scholarly journals A Relaxed Eddy Accumulation (REA) LOPAP-System for Flux Measurements of Nitrous Acid (HONO)

2021 ◽  
Author(s):  
Lisa von der Heyden ◽  
Walter Wißdorf ◽  
Ralf Kurtenbach ◽  
Jörg Kleffmann
Keyword(s):  
Nitrous Acid ◽  
Formation Mechanisms ◽  
Minor Importance ◽  
Night Time ◽  
Field Campaign ◽  
Air Masses ◽  
Relaxed Eddy Accumulation ◽  
Photolysis Frequency ◽  
Ultrasonic Anemometer ◽  
Flux Measurements

Abstract. In the present study a Relaxed Eddy Accumulation (REA) system for the quantification of vertical fluxes of nitrous acid (HONO) was developed and tested. The system is based on a three-channel-LOPAP instrument, for which two channels are used for the updrafts and downdrafts, respectively, and a third one for the correction of chemical interferences. The instrument is coupled to a REA gas inlet, for which an ultrasonic anemometer controls two fast magnetic valves to probe the two channels of the LOPAP instrument depending on the vertical wind direction. A software (PyREA) was developed, which controls the valves and measurement cycles, which regularly alternates between REA-, zero- and parallel ambient measurements. In addition, the assignment of the updrafts and downdrafts to the physical LOPAP channels is periodically alternated, to correct for differences in the interferences of the different air masses. During the study, only small differences of the interferences were identified for the updrafts and downdrafts excluding significant errors when using only one interference channel. In laboratory experiments, high precision of the two channels and the independence of the dilution corrected HONO concentrations on the length of the valve switching periods were demonstrated. A field campaign was performed in order to test the new REA-LOPAP system at the TROPOS monitoring station in Melpitz, Germany. HONO fluxes in the range of −4·1013 molecules m−2 s−1 (deposition) to +1.0·1014 molecules m−2 s−1 (emission) were obtained. A typical diurnal variation of the HONO fluxes was observed with low, partly negative fluxes during night-time and higher positive fluxes around noon. After an intensive rain period the positive HONO emissions during daytime were continuously increasing, which was explained by the drying of the upper most ground surfaces. Similar to other campaigns, the highest correlation of the HONO flux was observed with the product of the NO2 photolysis frequency and the NO2 concentration (J(NO2)·[NO2]), which implies a HONO formation by photosensitized conversion of NO2 on organic surfaces, like e.g. humic acids. Other postulated HONO formation mechanisms are also discussed, but are ranked being of minor importance for the present field campaign.

scholarly journals Effect of a New Manure Amendment on Ammonia Emissions from Poultry Litter

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 257
Author(s):  
Kelsey Anderson ◽  
Philip A. Moore ◽  
Jerry Martin ◽  
Amanda J. Ashworth
Keyword(s):  
Aluminum Sulfate ◽  
Management Practice ◽  
Block Design ◽  
Poultry Litter ◽  
Poultry Production ◽  
Ammonia Emissions ◽  
Best Management ◽  
Randomized Block Design ◽  
Flux Measurements ◽  
Ammonia Flux

Treating manure with aluminum sulfate (alum) is a best management practice (BMP) which reduces ammonia (NH3) emissions and phosphorus (P) runoff from poultry litter. However, the price of alum has increased markedly in recent years, creating a need for less expensive products to control NH3 volatilization. The objective of this study was to evaluate the effects of a new litter amendment made from alum mud, bauxite, and sulfuric acid (alum mud litter amendment or AMLA) on NH3 emissions, litter chemistry, and poultry production in a pen trial. Three separate flocks of 1000 broilers were used for this study. The first flock of birds was used to produce the poultry litter needed for the experiment. The second and third flocks of birds were allocated to 20 pens in a randomized block design with four replicates of five treatments: (1) control, (2) 49 kg AMLA/100 m2 incorporated, (3) 98 kg AMLA/100 m2 incorporated, (4) 98 kg AMLA/100 m2 surface applied, and (5) 98 kg alum/100 m2 incorporated. Ammonia flux measurements and litter samples were collected from each pen at day 0, 7, 14, 21, 28, 35, and 42. The average litter pH for both flocks was higher in untreated litter (7.92) compared to incorporating alum (7.32) or AMLA (7.18). The two flocks’ average NH4-N concentrations at day 42 were 38% and 30% higher for the high rates of incorporated alum and AMLA compared to the untreated litter. Compared with untreated litter, AMLA reduced overall NH3 emissions by 27% to 52% which was not significantly different from reductions in emissions by alum (35%). Alum mud litter amendment reduced cumulative NH3 losses from litter as much as, and in some cases more than, alum applied at the same rate. These data indicate that AMLA, which can be manufactured for lower price than alum, is an effective alternative litter amendment for reducing NH3 emissions from poultry litter.

scholarly journals Dynamics of ammonia exchange with cut grassland: synthesis of results and conclusions of the GRAMINAE Integrated Experiment

2009 ◽  
Vol 6 (1) ◽  
pp. 1121-1184 ◽  
Author(s):  
M. A. Sutton ◽  
E. Nemitz ◽  
C. Milford ◽  
C. Campbell ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Gradient Method ◽  
Close Agreement ◽  
Grassland Management ◽  
N Fertilization ◽  
Comprehensive Analysis ◽  
Vertical Flux ◽  
Flux Divergence ◽  
Relaxed Eddy Accumulation ◽  
Flux Measurements ◽  
Ammonia Exchange

Abstract. Improved data on biosphere-atmosphere exchange are fundamental to understanding the production and fate of ammonia (NH3) in the atmosphere. The GRAMINAE Integrated Experiment combined novel measurement and modelling approaches to provide the most comprehensive analysis of the interactions to date. Major inter-comparisons of micrometeorological parameters and NH3 flux measurements using the aerodynamic gradient method and relaxed eddy accumulation (REA) were conducted. These showed close agreement, though the REA systems proved insufficiently precise to investigate vertical flux divergence. Grassland management had a large effect on fluxes: Emissions increased after grass cutting (−50 to 700 ng m−2 s−1 NH3) and after N-fertilization (0 to 3800 ng m−2 s

Sign in / Sign up

Export Citation Format

Share Document