Measuring ammonia emissions from manured fields

Agricultural and Forest Meteorology

Ammonia (NH3) emission from animal manure contributes to air pollution and ecosystem degradation, and the loss of reactive nitrogen (N) from agricultural systems. Estimates of NH3 emission are necessary for national inventories and nutrient management, and NH3 emission from field-applied manure has been measured in many studies over the past few decades. In this work, we facilitate the use of these data by collecting and organizing them in the ALFAM2 database. In this paper we describe the development of the database and summarise its contents, quantify effects of application methods and other variables on emission using a data subset, and discuss challenges for data analysis and model development. The database contains measurements of emission, manure and soil properties, weather, application technique, and other variables for 1899 plots from 22 research institutes in 12 countries. Data on five manure types (cattle, pig, mink, poultry, mixed, as well as sludge and "other") applied to three types of crops (grass, small grains, maize, as well as stubble and bare soil) are included. Application methods represented in the database include broadcast, trailing hose, trailing shoe (narrow band application), and open slot injection. Cattle manure application to grassland was the most common combination, and analysis of this subset (with dry matter (DM) limited to <15%) was carried out using mixed-and fixed-effects models in order to quantify effects of management and environment on ammonia emission, and to highlight challenges for use of the database. Measured emission from cattle slurry ranged from < 1% to 130% of applied ammonia after 48 hours. Results showed clear, albeit variable, reductions in NH3 emission due to trailing hose, trailing shoe, and open slot injection of slurry compared to broadcast application. There was evidence of positive effects of air temperature and wind speed on NH3 emission, and limited evidence of effects of slurry DM. However, random-effects coefficients for differences among research institutes were among the largest model coefficients, and 4 showed a deviation from the mean response by more than 100% in some cases. The source of these institute differences could not be determined with certainty, but there is some evidence that they are related to differences in soils, or differences in application or measurement methods. The ALFAM2 database should be useful for development and evaluation of both emission factors and emission models, but users need to recognize the limitations caused by confounding variables, imbalance in the dataset, and dependence among observations from the same institute. Variation among measurements and in reported variables highlights the importance of international agreement on how NH3 emission should be measured, along with necessary types of supporting data and standard protocols for their measurement. Both are needed in order to produce more accurate and useful ammonia emission measurements. Expansion of the ALFAM2 database will continue, and readers are invited to contact the corresponding author for information on data submission. The latest version of the database is

Ammonia emission were measured from land applied FYM with three air velocity conditions (1, 2 and 3 m/s) and three application rates (20, 40 and 60 Mg/ha) by means of three Open Large Dynamic Chambers. Each device is made up of a ventilated chamber (24m2), a fan connected to a galvanized sheet iron pipe 10 m long - equipped with an internal flow conditioner-, and an air sampling system positioned at the end of the pipe. Two anemometers measure air velocity within the pipe and under the chamber. Measurements were carried out in two different temperature conditions (5-21°C - autumn season and 0- 7°C - winter season). Results of the carried out trials pointed out a significant effect of air velocity on ammonia emission, while no significant effect of the application rate. Environmental temperature signifi- cantly affected ammonia emission too. Autumn ammonia losses ranged between 10% and 28.6% of the total Nitrogen spread on the soil, while winter ones ranged from 5% to 18.7%.

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Ammonia emissions are produced in all manure management cycle stages: in the livestock housing period as well as during grazing, while manure is stored and incorporated to the soil. For ammonia emission estimation from manure management in Latvia the methodology described in the EMEP-EEA guidebook 2016 is used. The research paper covers all common livestock groups as well as the major manure handling and storage technology solutions in Latvia. The ammonia emissions are overviewed according to the level of calculations (Tier 1 or Tier 2), as well as typical characteristics of small or intensive management farms. The outcome of ammonia emissions increased by 50 %, if Tier 2 method was used for determination of dairy cattle ammonia emissions compared to Tier 1, for laying hens this difference is 32 %. Conventional farming contributes less ammonia emissions for dairy cattle (52 %) and laying hens (44 %) compared to intensive farming in the context of Tier 2 calculation approach, if abating solution quantitative expressions are not taken into account. Substantial reduction potential (up to 64 % for dairy cattle) can be reached for ammonia emission, if manure is used as feedstock for biogas production as direct use of manure is subtracted from Tier 2 calculations and for this research comparison purposes calculated using Tier 1 level methodology. The emission created from biogas production is necessary to report in the waste sector according to the UNECE Convention on Long-range Transboundary Air Pollution (CLRTAP)p directive. Quantitative estimation of abating and preventing solutions for ammonia emissions at all levels of manure management according to the country specific conditions is important.

Atmospheric Measurement Techniques Discussions, 2016

Ammonia (NH&lt;sub&gt;3&lt;/sub&gt;) fluxes were estimated from a field being grazed by dairy cattle during spring, by applying a backward-Lagrangian Stochastic model (bLS) model combined with horizontal concentration gradients measured across the field. Continuous concentration measurements at field boundaries were made by open-path miniDOAS (differential optical absorption spectroscopy) instruments, during the cattle’s presence and for 6 subsequent days. The deposition of emitted NH&lt;sub&gt;3&lt;/sub&gt; to ‘clean’ patches on the field was also simulated, allowing both ‘net’ and ‘gross’ emission estimates, where the dry deposition velocity (&lt;i&gt;v&lt;/i&gt;&lt;sub&gt;&lt;i&gt;d&lt;/i&gt;&lt;/sub&gt;) was predicted by a canopy resistance (&lt;i&gt;R&lt;sub&gt;c&lt;/sub&gt;&lt;/i&gt;) model developed from local NH&lt;sub&gt;3&lt;/sub&gt; flux and meteorological measurements. Estimated emissions peaked during grazing and decreased after the cattle had left the field, while cont...

Biogeosciences, 2012

The EMEP/EEA guidebook 2009 for agricultural emission inventories reports an average ammonia (NH 3) emission factor (EF) by volatilisation of 55 % of the applied total ammoniacal nitrogen (TAN) content for cattle slurry, and 35 % losses for pig slurry, irrespective of the type of surface or slurry characteristics such as dry matter content and pH. In this review article, we compiled over 350 measurements of EFs published between 1991 and 2011. The standard slurry application technique during the early years of this period, when a large number of measurements were made, was spreading by splash plate, and as a result reference EFs given in many European inventories are predominantly based on this technique. However, slurry application practices have evolved since then, while there has also been a shift in measurement techniques and investigated plot sizes. We therefore classified the available measurements according to the flux measurement technique or measurement plot size and year of measurement. Medium size plots (usually circles between 20 to 50 m radius) generally yielded the highest EFs. The most commonly used measurement setups at this scale were based on the Integrated Horizontal Flux method (IHF or the ZINST method (a simplified IHF method)). Several empirical models were published in the years 1993 to 2003 predicting NH 3 EFs as a function of meteorology and slurry characteristics (Menzi et al., 1998; Søgaard et al., 2002). More recent measurements show substantially lower EFs which calls for new measurement series in order to validate the various measurement approaches against each other and to derive revised inputs for inclusion into emission inventories.

Atmospheric Environment, 2007

During a measurement period from June till November 2004, ammonia fluxes above non-fertilized managed grassland in The Netherlands were measured with a Gradient Ammonia-High Accuracy-Monitor (GRAHAM). Compared with earlier ammonia measurement systems, the GRAHAM has higher accuracy and a quality control system. Flux measurements are presented for two different periods, i.e. a warm, dry summer period (from 18 July till 15 August) and a wet, cool autumn period (23 September till 23 October). From these measurements canopy compensation points were derived. The canopy compensation point is defined as the effective surface concentration of ammonia. In the summer period (negative) deposition fluxes are observed in the evening, night and early morning due to leaf surface wetness, while in the afternoon emission fluxes are observed due to high canopy compensation points. The mean NH 3 -flux in this period was 4 ng m À2 s À1 , which corresponds to a net emission of 0.10 kg N ha À1 over the 28 day sampling period. The NH 3 -flux in the autumn period mainly shows (negative) deposition fluxes due to small canopy compensation points caused by low temperatures and a generally wet surface. The mean NH 3 -flux in this period is À24 ng m À2 s À1 , which corresponds to a net deposition of 0.65 kg N ha À1 over the 31 day sampling period.

… Inventories Meeting Future …, 2005

Ammonia emissions from dairies may be a significant contributor to the San Joaquin Valley, CA, air problem. Our research is currently aimed at identifying and managing these emissions. On a dairy, a source of emissions comes from the dairy effluent filled lagoons. Firstly, we review the technology involved in the use of filter packs and open path tunable diode laser (OPTDL) for monitoring ammonia emissions. Then we present some of our research data collected to highlight the applicability of the OPTDL for monitoring diurnal and seasonal fluctuations of ammonia during various dairy management practices. For example, in a management system comprising of acidification of the dairy effluent acidification coupled with aeration and freshwater addition, we detected ammonia fluctuations as the pH and oxidation reduction potential levels of the lagoon water changed. In summary, we found that as the pH of the lagoon dropped from 8.0 to 6.5, average NH 3 fluxes decreased from approximately 1.6 to 0.5 mg/m^2/s. Generally, relatively high gas fluxes were detected at the start of the aeration, probably due to agitation of the lagoon, followed by a gradual reduction as the lagoon was subjected to further aeration, acidification, and fresh water addition. Due to the limited number of laser units available we are currently unable to obtain simultaneous upwind and downwind concentrations. Hence, a major draw back of using the data collected with the OPTDL in an EPA approved model to predict downwind concentrations from area sources was the determination of what portion of the measured concentration downwind of the lagoon was attributable to that source. Generally, the data collected with the TDL depicted the periods of relatively higher emissions occurring during the day and night times which generally go undetected with the filter pack sampling.

Soil Science Society of America Journal, 2015

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. Static Chamber Measurements of Ammonia Volatilization from Manured Soils: Impact of Deployment Duration and Manure Characteristics Nutrient Management & Soil & Plant Anaalysis Static chambers (SC) are a simple low-cost option for measuring NH 3 volatilization from agricultural soils. However, it is uncertain how their estimates relate to more sophisticated methods. In this study, we compared SCs and wind tunnels (WT) for the field measurement of NH 3 volatilization during 22 d following surface application of seven solid poultry manures to a bare agricultural soil. Our objective was to determine the impact of SC deployment duration and manure characteristics on the emission estimates. Total NH 3 losses measured using SCs were on average 23% lower than using WTs. This bias varied with deployment time as the SC/WT emission ratio increased from a value of 0.2 immediately following deployment to a plateau of 1.6, 8 d later. The performance of SCs was also influenced by manure type, with the SC/WT ratio ranging from 0.40 to 1.30 after 22 d. Globally we found that (i) shortly after deployment, absence of air movement inside SCs results in an underestimation of soil-surface NH 3 volatilization (»80%) compared with WT; (ii) this initial bias appears independent of the NH 3 source intensity; (iii) the underestimation decreases with deployment duration; and (iv) the cumulative bias after 22 d is impacted by the modified transformations of manure organic N (MON) inside SCs. We conclude that SCs yield biased absolute estimates of NH 3 volatilization rates in most situations. Furthermore, their use for comparing relative emission potential between various surface-applied solid manures is also limited to periods during which the transformation of the manure N is not affected by SC deployment.