scholarly journals N2O Emissions From Residues of Oat and Grass Pea Cover Crops Cultivated in the US Southern Great Plains

2021 ◽  
Vol 4 ◽  
Author(s):  
Hardeep Singh ◽  
Tanka P. Kandel ◽  
Prasanna H. Gowda ◽  
Brian K. Northup ◽  
Vijaya G. Kakani
Keyword(s):  
Great Plains ◽  
Cover Crops ◽  
Aboveground Biomass ◽  
Grass Pea ◽  
Management Options ◽  
Total N ◽  
Southern Great Plains ◽  
The Us ◽  
And Control ◽  
Summer Crop

Grass pea (Lathyrus sphaericus) and oat (Avena sativa) are potential cover crops for spring periods of summer crop systems in the US Southern Great Plains (SGP). The main objective of this study was to compare nitrous oxide (N2O) emissions from residues of grass pea and oat grown as green nitrogen (N) crops. The comparisons included responses from plots cultivated with oat, grass pea, and control (spring-fallowed) plots. Two management options were applied to grass pea: residues retained and aboveground biomass removed for forage. Crabgrass (Digitaria sanguinalis) was cultivated as a main summer crop immediately after termination of the cover crops. Fluxes of N2O were measured by closed chamber connected to a portable gas analyzer on 23 dates during a 3 month growing period for crabgrass. At termination, oat produced more aboveground biomass than grass pea (2.17 vs. 3.56 Mg ha−1), but total N in biomass was similar (102–104 kg ha−1) due to greater N concentrations in grass pea than oat (4.80% vs. 2.86% of dry mass). Three month cumulative emissions of N2O from grass pea-incorporated plots (0.76 ± 0.11 kg N2O-N ha−1; mean ± standard error, n = 3) were significantly lower than from oat-incorporated plots (1.26 ± 0.14 kg N2O-N ha−1). Emissions from grass pea plots with harvested biomass (0.48 ± 0.04 kg N2O-N ha−1) were significantly lower than those from grass pea-incorporated plots. Cumulative N2O emissions from control plots were significantly greater than those from grass pea-harvested plots but were similar to the emissions from grass pea-incorporated plots. Yields produced by crabgrass were similar from all cover crop treatments (8.65–10.46 Mg ha−1), but yield responses to the control (18.53 Mg ha−1) were significantly larger. Nitrogen concentrations in crabgrass were greater in response to oat- and grass pea-incorporated plots (2.86–2.87%) than in grass pea-harvested (1.93%) and control (1.44%) plots. In conclusion, the results indicated that (i) post-incorporation emissions of N2O can be greater from a non-legume green N crop than a legume green N crop due to greater biomass productivity of the cereal, and (ii) emissions of N2O could be mitigated by removing biomass of the green N crop for use as forage.

scholarly journals Modeling Resource Use Responses to Macroeconomic Changes: Water in the US Southern Great Plains

2013 ◽  
Vol 04 (01) ◽  
pp. 8-19
Author(s):  
Justin Weinheimer ◽  
Erin Wheeler-Cook ◽  
Don Ethridge ◽  
Darren Hudson
Keyword(s):  
Great Plains ◽  
Resource Use ◽  
Southern Great Plains ◽  
The Us

scholarly journals Ten Years of Aerosol Effects on Single-Layer Overcast Clouds over the US Southern Great Plains and the China Loess Plateau

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Hongru Yan ◽  
Tianhe Wang
Keyword(s):  
Great Plains ◽  
Indirect Effect ◽  
Negative Relationship ◽  
Single Layer ◽  
Cloud Base ◽  
Atmospheric Conditions ◽  
Southern Great Plains ◽  
Aerosol Loading ◽  
The Us ◽  
The Impact

Using almost 10 years of observations of clouds and aerosols from the US Southern Great Plains (SGP) atmospheric observatory and the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) in China, the impact of aerosols on single-layer overcast clouds over continental land for different regimes were investigated. Atmospheric conditions at the two sites were first compared in an attempt to isolate the influence of aerosols on cloud properties from dynamic and thermodynamic influences. Cloud types and amounts are similar at the two sites. The dominant aerosol types at the SGP and SACOL sites are sulphate and dust, respectively, with greater aerosol optical depths (AODs) and absorption at the SACOL site. Aerosol first indirect effect (FIE) ranges from 0.021 to 0.152 and from −0.078 to 0.047 at the SGP and SACOL sites, respectively, when using the AOD below cloud base as CCN proxy. Although differences exist, the influence of meteorological conditions on the FIE at the two sites is consistent. FIEs are easily detected under descending motion and dry condition. The FIE at the SGP site is larger than that at the SACOL site, which suggests that the cloud albedo effect is more sensitive under relatively cleaner atmospheric conditions and the dominating aerosol at the SACOL site has less hygroscopicity. The radiative forcing of the FIE over the SGP site is −3.2 W m−2 for each 0.05 increment in FIE. Cloud durations generally prolong as aerosol loading increases, which is consistent with the hypothesis of the aerosol second indirect effect. The negative relationship between cloud duration time and aerosol loading when aerosol loading reaches a large value further might suggest a semidirect effect.

Agricultural management effects on soil health across the US Southern Great Plains

2019 ◽  
Vol 74 (5) ◽  
pp. 419-425
Author(s):  
C.M. Rottler ◽  
J.L. Steiner ◽  
D.P. Brown ◽  
S.E. Duke
Keyword(s):  
Great Plains ◽  
Soil Health ◽  
Agricultural Management ◽  
Southern Great Plains ◽  
The Us ◽  
Management Effects

scholarly journals A multi-year record of airborne CO<sub>2</sub> observations in the US Southern Great Plains

2012 ◽  
Vol 5 (5) ◽  
pp. 7187-7222 ◽  
Author(s):  
S. C. Biraud ◽  
M. S. Torn ◽  
J. R. Smith ◽  
C. Sweeney ◽  
W. J. Riley ◽  
...  
Keyword(s):  
Great Plains ◽  
Meteorological Data ◽  
Carbonyl Sulfide ◽  
Co2 Concentration ◽  
Vertical Profiles ◽  
Southern Great Plains ◽  
Airborne Measurements ◽  
Mauna Loa ◽  
Co2 Concentrations ◽  
The Us

Abstract. We report on 10 yr of airborne measurements of atmospheric CO2 concentrations from continuous and flask systems, collected between 2002 and 2012 over the Atmospheric Radiation Measurement Program Climate Research Facility in the US Southern Great Plains (SGP). These observations were designed to quantify trends and variability in atmospheric concentrations of CO2 and other greenhouse gases with the precision and accuracy needed to evaluate ground-based and satellite-based column CO2 estimates, test forward and inverse models, and help with the interpretation of ground-based CO2 concentration measurements. During flights, we measured CO2 and meteorological data continuously and collected flasks for a rich suite of additional gases: CO2, CO, CH4, N2O, 13CO2, carbonyl sulfide (COS), and trace hydrocarbon species. These measurements were collected approximately twice per week by small aircraft (Cessna 172 first, then Cessna 206) on a series of horizontal legs ranging in altitude from 460 m to 5300 m (a.m.s.l.). Since the beginning of the program, more than 400 continuous CO2 vertical profiles have been collected (2007–2012), along with about 330 profiles from NOAA/ESRL 12-flask (2006–2012) and 284 from NOAA/ESRL 2-flask (2002–2006) packages for carbon cycle gases and isotopes. Averaged over the entire record, there were no systematic differences between the continuous and flask CO2 observations when they were sampling the same air, i.e. over the one-minute flask-sampling time. Applying the concept of broadband validation, we documented a mean difference of <0.1 ppm between instruments. However, flask data were not equivalent in all regards; horizontal variability in CO2 concentrations within the 5–10 min legs sometimes resulted in significant differences between flask and continuous measurement values for those legs, and the information contained in fine-scale variability about atmospheric transport was not captured by flask-based observations. The annual CO2 concentration trend at 3000 m (a.m.s.l.) was 1.91 ppm yr−1 between 2008 and 2010, very close to the concurrent trend at Mauna Loa of 1.95 ppm yr−1. The seasonal amplitude of CO2 concentration in the Free Troposphere (FT) was half that in the PBL (∼15 ppm vs. ∼30 ppm) and twice that at Mauna Loa (approximately 8 ppm). The CO2 horizontal variability was up to 10 ppm in the PBL and less than 1 ppm at the top of the vertical profiles in the FT.

scholarly journals Sky cover from MFRSR observations

2011 ◽  
Vol 4 (7) ◽  
pp. 1463-1470 ◽  
Author(s):  
E. Kassianov ◽  
J. C. Barnard ◽  
L. K. Berg ◽  
C. Flynn ◽  
C. N. Long
Keyword(s):  
Great Plains ◽  
Visible Spectral Range ◽  
Department Of Energy ◽  
Research Facility ◽  
Southern Great Plains ◽  
Clear Sky ◽  
The Us ◽  
Atmospheric Radiation Measurement ◽  
Main Components ◽  
Good Agreement

Abstract. The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR). The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

scholarly journals A multi-year record of airborne CO<sub>2</sub> observations in the US Southern Great Plains

2013 ◽  
Vol 6 (3) ◽  
pp. 751-763 ◽  
Author(s):  
S. C. Biraud ◽  
M. S. Torn ◽  
J. R. Smith ◽  
C. Sweeney ◽  
W. J. Riley ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Great Plains ◽  
Atmospheric Transport ◽  
Meteorological Data ◽  
Carbonyl Sulfide ◽  
Vertical Profiles ◽  
Southern Great Plains ◽  
Airborne Measurements ◽  
Mauna Loa ◽  
The Us

Abstract. We report on 10 yr of airborne measurements of atmospheric CO2 mole fraction from continuous and flask systems, collected between 2002 and 2012 over the Atmospheric Radiation Measurement Program Climate Research Facility in the US Southern Great Plains (SGP). These observations were designed to quantify trends and variability in atmospheric mole fraction of CO2 and other greenhouse gases with the precision and accuracy needed to evaluate ground-based and satellite-based column CO2 estimates, test forward and inverse models, and help with the interpretation of ground-based CO2 mole-fraction measurements. During flights, we measured CO2 and meteorological data continuously and collected flasks for a rich suite of additional gases: CO2, CO, CH4, N2O, 13CO2, carbonyl sulfide (COS), and trace hydrocarbon species. These measurements were collected approximately twice per week by small aircraft (Cessna 172 initially, then Cessna 206) on a series of horizontal legs ranging in altitude from 460 m to 5500 m a.m.s.l. Since the beginning of the program, more than 400 continuous CO2 vertical profiles have been collected (2007–2012), along with about 330 profiles from NOAA/ESRL 12-flask (2006–2012) and 284 from NOAA/ESRL 2-flask (2002–2006) packages for carbon cycle gases and isotopes. Averaged over the entire record, there were no systematic differences between the continuous and flask CO2 observations when they were sampling the same air, i.e., over the one-minute flask-sampling time. Using multiple technologies (a flask sampler and two continuous analyzers), we documented a mean difference of < 0.2 ppm between instruments. However, flask data were not equivalent in all regards; horizontal variability in CO2 mole fraction within the 5–10 min legs sometimes resulted in significant differences between flask and continuous measurement values for those legs, and the information contained in fine-scale variability about atmospheric transport was not captured by flask-based observations. The CO2 mole fraction trend at 3000 m a.m.s.l. was 1.91 ppm yr−1 between 2008 and 2010, very close to the concurrent trend at Mauna Loa of 1.95 ppm yr−1. The seasonal amplitude of CO2 mole fraction in the free troposphere (FT) was half that in the planetary boundary layer (PBL) (~ 15 ppm vs. ~ 30 ppm) and twice that at Mauna Loa (approximately 8 ppm). The CO2 horizontal variability was up to 10 ppm in the PBL and less than 1 ppm at the top of the vertical profiles in the FT.

scholarly journals Comparison of Vaisala radiosondes RS41 and RS92 at the ARM Southern Great Plains Site

2015 ◽  
Vol 8 (11) ◽  
pp. 11323-11368 ◽  
Author(s):  
M. P. Jensen ◽  
D. Holdridge ◽  
P. Survo ◽  
R. Lehtinen ◽  
S. Baxter ◽  
...  
Keyword(s):  
Great Plains ◽  
Measurement Accuracy ◽  
Atmospheric Temperature ◽  
Atmospheric Radiation ◽  
Atmospheric Conditions ◽  
North Central ◽  
Southern Great Plains ◽  
The Us ◽  
Atmospheric Radiation Measurement

Abstract. In the fall of 2013, the Vaisala RS41-SG (4th generation) radiosonde was introduced as a replacement for the RS92-SGP radiosonde with improvements in measurement accuracy of profiles of atmospheric temperature, humidity and pressure. In order to help characterize these improvements, an intercomparison campaign was undertaken at the US Department of Energy's Atmospheric Radiation Measurement (ARM) Facility site in north Central Oklahoma USA. During 3–8 June 2014, a total of 20 twin-radiosonde flights were performed in a variety of atmospheric conditions representing typical midlatitude continental summertime conditions. The results suggest that the RS92 and RS41 measurements generally agree within manufacturer specified tolerances with notable exceptions when exiting liquid cloud layers where the "wet bulbing" effect is mitigated in the RS41 observations. The RS41 measurements also appear to show a smaller impact from solar heating. These results suggest that the RS41 does provide important improvements, particularly in cloudy conditions, but under most observational conditions the RS41 and RS92 measurements agree within the manufacturer specified limits and so a switch to RS41 radiosondes will have little impact on long-term observational records.

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