<i>Empirical Model of Annual Nitrous Oxide Emissions from Open-Lot Beef Cattle Feedyard Pens (Version 2)</i>

2019 ◽  
Author(s):  
David B. Parker ◽  
Kenneth D. Casey ◽  
Erin L. Cortus ◽  
Byeng R. Min ◽  
Heidi M. Waldrip ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Beef Cattle ◽  
Empirical Model ◽  
Nitrous Oxide Emissions

<i>Empirical Model of Annual Nitrous Oxide Emissions from Open-Lot Beef Cattle Feedyard Pens in the Southern High Plains</i>

2018 ◽  
Author(s):  
David B. Parker ◽  
Erin Cortus ◽  
Kenneth D. Casey ◽  
Gary W. Marek ◽  
Kevin R. Heflin ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Beef Cattle ◽  
Empirical Model ◽  
Nitrous Oxide Emissions ◽  
High Plains ◽  
Southern High Plains

Toward Modeling of Nitrous Oxide Emissions Following Precipitation, Urine, and Feces Deposition on Beef Cattle Feedyard Surfaces

2020 ◽  
Vol 63 (5) ◽  
pp. 1371-1384
Author(s):  
David B. Parker ◽  
Kenneth D. Casey ◽  
Kristin E. Hales ◽  
Heidi M. Waldrip ◽  
Byeng Min ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Beef Cattle ◽  
Greenhouse Gas ◽  
Empirical Modeling ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
List Type ◽  
Equivalent Mass ◽  
Fresh Feces ◽  
Feces Deposition

HighlightsNitrous oxide is a greenhouse gas emitted from feedyard pen surfaces.Experiments were conducted to quantify nitrous oxide emissions from precipitation, urine, and feces.Nitrous oxide emissions from urine were about 30% of those from equal amounts of precipitation.Regression equations were developed for empirical modeling of emissions.Abstract. The amount of moisture deposited annually as urine (~320 mm) and feces (~95 mm) on typical semi-arid Texas beef cattle feedyard pens is considerable compared to the regional 470 mm mean annual precipitation. Precipitation is a primary factor affecting nitrous oxide (N2O) emissions from manure, but specific effects of urine and feces deposition are unknown. The objectives of this research were to (1) quantify N2O emissions following precipitation, urine, and feces deposition on a dry feedyard manure surface, and (2) develop equations for future empirical modeling of these emissions. Four experiments (Exp.) were conducted using recirculating flux chambers to quantify N2O emissions. Exp. 1 had treatments (TRT) of water (W), artificial urine (AU), and two urines collected from beef cattle fed high-quality forage (FU) or corn-based concentrate (CU). Exp. 2 had TRT of W, AU, and two feces levels (Fx1 and Fx2). In Exp. 3, N2O emissions were quantified from fresh feces pats. In Exp. 4, the effect of rainfall pH on N2O emissions was evaluated. Results from Exp. 1 showed that the W TRT had the highest mean cumulative N2O emission, while AU, FU, and CU ranged from 31.0% to 70.0% of W on an equal volume-applied basis. There was little correlation between N2O emissions and urine or water nitrogen (N) content. In Exp. 2, W again had the highest cumulative N2O. Cumulative N2O emissions expressed per unit of water added were 29.0, 3.8, 4.5, and 5.1 mg N kg-1 water added for W, AU, Fx1, and Fx2, respectively. In Exp. 3, fresh feces pats emitted no direct N2O, but N2O originated from the dry manure beneath the feces pat due to wetting. In Exp. 4, the highest N2O emissions occurred at pH 5 and pH 8, with lower emissions at pH 6 and pH 7. This research has shown that the addition of moisture to the pen surface from urine and feces contributes considerably to N2O emissions as compared to precipitation alone. The following recommendations were developed for future empirical modeling purposes: (1) N2O emissions from urine should be calculated as 32.7% of those emissions from the equivalent mass deposition of water, and (2) N2O emissions resulting from the mass of water in feces should be calculated as 15.6% of those emissions from the equivalent mass deposition of water. Keywords: Beef cattle, Greenhouse gas, Manure, Nitrous oxide, Urine, Precipitation.

Nitrapyrin Reduced Nitrous Oxide Emissions from Beef Cattle Urine Patches on a Semiarid Tame Pasture

2017 ◽  
Vol 81 (6) ◽  
pp. 1537-1547 ◽  
Author(s):  
Ben W. Thomas ◽  
Xinlei Gao ◽  
Jessica L. Stoeckli ◽  
Ryan Beck ◽  
Kui Liu ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Beef Cattle ◽  
Nitrous Oxide Emissions

Nitrous Oxide Emissions from an Open-Lot Beef Cattle Feedyard in Texas

2019 ◽  
Vol 62 (5) ◽  
pp. 1173-1183
Author(s):  
David B. Parker ◽  
Kenneth D. Casey ◽  
Heidi M. Waldrip ◽  
Byeng R. Min ◽  
Bryan L. Woodbury ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Beef Cattle ◽  
Spatial Variability ◽  
Greenhouse Gas ◽  
Field Research ◽  
Background Level ◽  
Nitrous Oxide Emissions ◽  
Simulated Rainfall ◽  
Flux Chamber ◽  
Arithmetic Means

Abstract. Nitrous oxide (N2O) is a greenhouse gas (GHG) with a global warming potential much greater than that of carbon dioxide (CO2). Nitrous oxide is emitted from the manure-covered pen surfaces of open-lot beef cattle feedyards, and more than six million beef cattle are fed in the Southern Great Plains. A field research project was conducted to determine the temporal and spatial variability of N2O emissions from the pen surfaces of a commercial feedyard before and after simulated rainfall. Two week-long monitoring cycles were conducted in April and August 2018 in the Texas Panhandle. Temporal variability was assessed using six continuous automated flux chambers per pen, and spatial variability was assessed using a portable chamber at up to 61 locations in a single pen. Diurnal fluxes varied 5-fold to 10-fold over a 24 h period. Flux varied seasonally, with arithmetic means of 0.56 mg N2O-N m-2 h-1 in April and 3.21 mg N2O-N m-2 h-1 in August. Fluxes measured spatially across the pen surface over a 2 h period at midday were lognormally distributed, with April geometric and arithmetic means of -0.81 and 0.80 mg N2O-N m-2 h-1, respectively, and August geometric and arithmetic means of 0.095 and 2.6 mg N2O-N m-2 h-1, respectively. Fluxes peaked shortly after simulated rainfall. Arithmetic mean N2O-N flux for the 2 d after rainfall increased over the background level by 4.6-fold in April and 1.7-fold in August. Manure properties measured at the time of flux measurement were poorly correlated with N2O emissions and were of little value for predicting N2O emissions, which confirmed that further work is warranted on the biochemistry of feedyard manure. The results of this field research will help refine models for predicting N2O emissions from open-lot beef cattle feedyards and help to develop effective mitigation methods to conserve feedyard N. Keywords: Beef cattle, Flux chamber, Greenhouse gas, Manure, Nitrous oxide, Rainfall.

Nitrous Oxide Emissions from Southern High Plains Beef Cattle Feedyards: Measurement and Modeling

2017 ◽  
Vol 60 (4) ◽  
pp. 1209-1221 ◽  
Author(s):  
Heidi M. Waldrip ◽  
Kenneth D. Casey ◽  
Richard W. Todd ◽  
David B. Parker
Keyword(s):  
Nitrous Oxide ◽  
Organic Matter ◽  
Beef Cattle ◽  
Empirical Models ◽  
Nitrous Oxide Emissions ◽  
Emission Rates ◽  
Cattle Production ◽  
Model Predictions ◽  
Texas Panhandle ◽  
Process Based Models

Abstract. The Texas Panhandle produces approximately 42% of finished beef in the U.S., and cattle production is estimated to contribute 8 Tg carbon dioxide equivalents (CO2e) from nitrous oxide (N2O). Production of N2O in manure is largely a result of biochemical processes that are not static: N2O emission rates are dependent on numerous environmental and chemical factors. Process-based models that estimate N2O emissions from manure in open-lot cattle production systems typically rely on information derived from studies of soil biochemistry. Limited study has been conducted on manure-derived N2O in open-lot beef feedyards. The objectives of this study were to determine variables related to N2O losses from Texas Panhandle feedyards and develop empirical models to predict N2O emissions. Nitrous oxide flux data were collected from a series of 15 non-flow-through, non-steady-state (NFT-NSS) chamber studies (ten chambers per study) conducted from 2012 to 2014 on two commercial beef cattle feedyards. Manure samples (loose surface manure and the underlying manure pack) were analyzed for basic physicochemical properties, soluble carbon (C) and nitrogen (N), and ultraviolet-visible (UV-vis) spectral characteristics related to degree of organic matter (OM) stability and humification. Measured N2O emissions ranged from below detection to 101 mg m-2 h-1 (average 4.8 ±12 mg m-2 h-1) and were positively related to manure H2O content, temperature, and nitrate (NO3-) concentration (p &lt; 0.01). Emissions were negatively related to manure OM, ammonia/ammonium (NH3/NH4+), dissolved C and dissolved N concentrations, and UV-vis parameters related to OM stability (p &lt; 0.05). Based on these data, empirical models were developed and evaluated to predict manure-derived N2O emissions. Model predictions were not significantly different from observed N2O emissions (p &lt; 0.05). The unbounded index of agreement (IA) indicated that model predictions were within 52% to 61% agreement with observations. Inclusion of OM characteristics improved model predictions of high (&gt;30 mg m-2 h-1) N2O emissions but tended to overestimate low emission rates (&lt;20 mg N2O m-2 h-1). This provides evidence for the importance of C stability in limiting manure N2O production. These models may improve parameterization of existing process-based models and are novel methods for predicting feedyard N2O emissions. Keywords: Beef cattle, Feedlot, Feedyard, Greenhouse gas, Manure, Modeling, Nitrous oxide, Organic matter, Urine, UV-vis spectroscopy.

An empirical model and scenario analysis of nitrous oxide emissions from a fertilised and grazed grassland site in Ireland

2007 ◽  
Vol 79 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Michael J. Hawkins ◽  
Bernard P. Hyde ◽  
Michael Ryan ◽  
R. P. O. Schulte ◽  
John Connolly
Keyword(s):  
Nitrous Oxide ◽  
Empirical Model ◽  
Scenario Analysis ◽  
Nitrous Oxide Emissions ◽  
Grassland Site ◽  
Grazed Grassland
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