scholarly journals 175 Effect of age at calving on greenhouse gas emissions from simulated beef farms grazing four stockpiled forage species in late fall/early winter

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 131-132
Author(s):  
Megan E Donnelly ◽  
Kim Ominski ◽  
E J McGeough ◽  
Karin Wittenberg ◽  
Getahun Legesse

Abstract The impact of age at first calving (2 versus 3 yrs) and type of forage species grazed in late fall/early winter on lifetime greenhouse gas (GHG) emissions from a cow-calf herd over an 8 or 9 yr period was examined. Farm simulations, based in Manitoba, Canada, were assessed using the Holos model to determine whole-farm GHG emissions for each scenario. The baseline herd consisted of 170 cows, 6 bulls, and their progeny which were sold at weaning, apart from herd replacements. Each simulation began with 207 newborn, female calves, with GHG emissions measured annually. From October to December, 1 of 4 stockpiled forages/forage mixtures were grazed: i) standing corn (COR), ii) tall fescue/meadow bromegrass (TFM), iii) orchardgrass/alfalfa (OGA), and iv) tall fescue/alfalfa/cicer milkvetch (TAC). All other feeding phase diets did not differ across all scenarios. Herd GHG emissions (Mg CO2e) were lower with heifers calving at 2 yrs (3,938 ± 71 Mg CO2e) versus 3 yrs (4,634 ± 72 Mg CO2e). Enteric methane (CH4) was the largest source of GHG emissions accounting for 66% of the total in both the 2- and 3-yr scenarios. Average enteric CH4 values were 3,820±61, 4,251 ± 68, 4,887±79, and 4,220 ± 68 Mg CO2e for simulations grazing COR, TFM, OGA, and TAC, respectively and were inversely related to total digestible nutrient (TDN) content of the forage mixtures with 72, 54, 45 and 55% TDN. Emissions were highest from OGA, the lowest quality forage, in both calving scenarios. Nitrous oxide emissions from livestock manure were the second highest contributing source, representing 15% of total emissions. Reducing age at first calving (2 versus 3 yrs) and providing higher energy forage in late fall/early winter reduced cow-calf GHG emissions. The adoption of management strategies such as reducing age at first calving and improving forage quality for extended grazing may reduce emissions from the cow-calf sector.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue Hao ◽  
Yu Ruihong ◽  
Zhang Zhuangzhuang ◽  
Qi Zhen ◽  
Lu Xixi ◽  
...  

AbstractGreenhouse gas (GHG) emissions from rivers and lakes have been shown to significantly contribute to global carbon and nitrogen cycling. In spatiotemporal-variable and human-impacted rivers in the grassland region, simultaneous carbon dioxide, methane and nitrous oxide emissions and their relationships under the different land use types are poorly documented. This research estimated greenhouse gas (CO2, CH4, N2O) emissions in the Xilin River of Inner Mongolia of China using direct measurements from 18 field campaigns under seven land use type (such as swamp, sand land, grassland, pond, reservoir, lake, waste water) conducted in 2018. The results showed that CO2 emissions were higher in June and August, mainly affected by pH and DO. Emissions of CH4 and N2O were higher in October, which were influenced by TN and TP. According to global warming potential, CO2 emissions accounted for 63.35% of the three GHG emissions, and CH4 and N2O emissions accounted for 35.98% and 0.66% in the Xilin river, respectively. Under the influence of different degrees of human-impact, the amount of CO2 emissions in the sand land type was very high, however, CH4 emissions and N2O emissions were very high in the artificial pond and the wastewater, respectively. For natural river, the greenhouse gas emissions from the reservoir and sand land were both low. The Xilin river was observed to be a source of carbon dioxide and methane, and the lake was a sink for nitrous oxide.


Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 563
Author(s):  
Kelsey Anderson ◽  
Philip A. Moore ◽  
Jerry Martin ◽  
Amanda J. Ashworth

Gaseous emissions from poultry litter causes production problems for producers as well as the environment, by contributing to climate change and reducing air quality. Novel methods of reducing ammonia (NH3) and greenhouse gas (GHG) emissions in poultry facilities are needed. As such, our research evaluated GHG emissions over a 42 d period. Three separate flocks of 1000 broilers were used for this study. The first flock was used only to produce litter needed for the experiment. The second and third flocks were allocated to 20 pens in a randomized block design with four replicated of five treatments. The management practices studied included an unamended control; a conventional practice of incorporating aluminum sulfate (referred to as alum) at 98 kg/100 m2); a novel litter amendment made from alum mud, bauxite, and sulfuric acid (alum mud litter amendment, AMLA) applied at different rates (49 and 98 kg/100 m2) and methods (surface applied or incorporated). Nitrous oxide emissions were low for all treatments in flocks 2 and 3 (0.40 and 0.37 mg m2 hr−1, respectively). The formation of caked litter (due to excessive moisture) during day 35 and 42 caused high variability in CH4 and CO2 emissions. Alum mud litter amendment and alum did not significantly affect GHGs emissions from litter, regardless of the amendment rate or application method. In fact, litter amendments such as alum and AMLA typically lower GHG emissions from poultry facilities by reducing ventilation requirements to maintain air quality in cooler months due to lower NH3 levels, resulting in less propane use and concomitant reductions in CO2 emissions.


2017 ◽  
Vol 6 (2) ◽  
pp. 66 ◽  
Author(s):  
Maria Storrle ◽  
Hans-Jorg Brauckmann ◽  
Gabriele Broll

This study investigates the amounts of greenhouse gas (GHG) emissions due to manure handling within different livestock production systems in Tyumen oblast of Western Siberia. Tyumen oblast occupies approx. 160 000 km² of Asian taiga and forest steppe. The amount of GHGs from manure was calculated as a function of the handling according to current IPCC guidelines for ecozones and livestock production systems. The entire Tyumen oblast has annual 7 400 t methane emissions and 440 t nitrous oxide emissions from manure. Three livestock production systems are prevalent in Tyumen oblast: Mega farms, small farms and peasant farms. The share of mega farms is 81 % (171 kt CO2 eq). Additionally, the slurry system in mega farms causes environmental pollution. GHG emissions and environmental pollution could be reduced by implementing solid manure systems or pasturing, by installing storage facilities for slurry outside the stables and through application of the manure as fertiliser at mega farms. In small farms solid manure systems and a small stocking density of livestock lead to smallest GHG emissions (1 %, 3 kt CO2 eq) from manure. In peasant farming 18 % (38 kt CO2 eq) of GHGs are emitted due to pasturing. 


Soil Research ◽  
2017 ◽  
Vol 55 (3) ◽  
pp. 201 ◽  
Author(s):  
A. R. Melland ◽  
D. L. Antille ◽  
Y. P. Dang

Occasional strategic tillage (ST) of long-term no-tillage (NT) soil to help control weeds may increase the risk of water, erosion and nutrient losses in runoff and of greenhouse gas (GHG) emissions compared with NT soil. The present study examined the short-term effect of ST on runoff and GHG emissions in NT soils under controlled-traffic farming regimes. A rainfall simulator was used to generate runoff from heavy rainfall (70mmh–1) on small plots of NT and ST on a Vertosol, Dermosol and Sodosol. Nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) fluxes from the Vertosol and Sodosol were measured before and after the rain using passive chambers. On the Sodosol and Dermosol there was 30% and 70% more runoff, respectively, from ST plots than from NT plots, however, volumes were similar between tillage treatments on the Vertosol. Erosion was highest after ST on the Sodosol (8.3tha–1 suspended sediment) and there were no treatment differences on the other soils. Total nitrogen (N) loads in runoff followed a similar pattern, with 10.2kgha–1 in runoff from the ST treatment on the Sodosol. Total phosphorus loads were higher after ST than NT on both the Sodosol (3.1 and 0.9kgha–1, respectively) and the Dermosol (1.0 and 0.3kgha–1, respectively). Dissolved nutrient forms comprised less than 13% of total losses. Nitrous oxide emissions were low from both NT and ST in these low-input systems. However, ST decreased CH4 absorption from both soils and almost doubled CO2 emissions from the Sodosol. Strategic tillage may increase the susceptibility of Sodosols and Dermosols to water, sediment and nutrient losses in runoff after heavy rainfall. The trade-offs between weed control, erosion and GHG emissions should be considered as part of any tillage strategy.


2009 ◽  
Vol 55 (No. 8) ◽  
pp. 311-319 ◽  
Author(s):  
Z. Exnerová ◽  
E. Cienciala

As a part of its obligations under the Climate Convention, the Czech Republic must annually estimate and report its anthropogenic emissions of greenhouse gases. This also applies for the sector of agriculture, which is one of the greatest producers of methane and nitrous oxide emissions. This paper presents the approaches applied to estimate emissions in agricultural sector during the period 1990–2006. It describes the origin and sources of emissions, applied methodology, parameters and emission estimates for the sector of agriculture in the country. The total greenhouse gas emissions reached 7644 Gg CO<sub>2</sub> eq. in 2006. About 59% (4479 Gg CO<sub>2</sub> eq.) of these emissions has originated from agricultural soils. This quantity ranks agriculture as the third largest sector in the Czech Republic representing 5.3% of the total greenhouse gas emissions (GHG). The emissions under the Czech conditions consist mainly of emissions from enteric fermentation, manure management and agricultural soils. During the period 1990–2006, GHG emissions from agriculture decreased by 50%, which was linked to reduced cattle population and amount of applied fertilizers. The study concludes that the GHG emissions in the sector of agriculture remain significant and their proper assessment is required for sound climate change adaptation and mitigation policies.


2006 ◽  
Vol 86 (3) ◽  
pp. 355-371 ◽  
Author(s):  
S M McGinn

Carbon dioxide, methane and nitrous oxide emissions from agricultural sources have a significant role in the overall enhancement of the global greenhouse gas (GHG) effect. In research, measurements of GHG emissions are made to improve upon emission factors used in national inventories, identify and promote mitigation practices, and drive policy on GHG emissions in agriculture. These measurements are fundamental to the process of better management of GHG emissions. There is a variety of measurement techniques used in GHG research depending on the measurement environment and available resources. Techniques that use chambers or micrometeorological measurements are commonly employed for calculating emissions of GHG from point sources in agriculture, such as livestock and manure-holding facilities. This review examines these techniques, their limitations, and discusses methods to quantify their accuracy and precision. Emerging techniques like the use of dispersion models provide opportunities to directly determine emissions from whole farms. A few micrometeorological techniques (integrated horizontal flux and mass difference) are ideal for point sources such as manure storage facilities. For smaller sources, chambers are still recommended. In designing GHG emission studies, employing more than one technique when measuring GHG emissions is recommended, as often differences can exist due to technique. Ideally, a controlled release of the target gas, and its recovery, should also be conducted to evaluate techniques prior to their application. Although many techniques are often sensitive enough to quantify mitigation practices, i.e., the relative change in emissions, it is more difficult to determine “ true”emission factors as required for inventory work. It follows that the precision and accuracy of the techniques must accompany their application when estimating GHG emissions. Key words: Greenhouse gas, techniques, chambers, methane, agriculture, cattle


2007 ◽  
Vol 363 (1492) ◽  
pp. 789-813 ◽  
Author(s):  
Pete Smith ◽  
Daniel Martino ◽  
Zucong Cai ◽  
Daniel Gwary ◽  
Henry Janzen ◽  
...  

Agricultural lands occupy 37% of the earth's land surface. Agriculture accounts for 52 and 84% of global anthropogenic methane and nitrous oxide emissions. Agricultural soils may also act as a sink or source for CO 2 , but the net flux is small. Many agricultural practices can potentially mitigate greenhouse gas (GHG) emissions, the most prominent of which are improved cropland and grazing land management and restoration of degraded lands and cultivated organic soils. Lower, but still significant mitigation potential is provided by water and rice management, set-aside, land use change and agroforestry, livestock management and manure management. The global technical mitigation potential from agriculture (excluding fossil fuel offsets from biomass) by 2030, considering all gases, is estimated to be approximately 5500–6000 Mt CO 2 -eq. yr −1 , with economic potentials of approximately 1500–1600, 2500–2700 and 4000–4300 Mt CO 2 -eq. yr −1 at carbon prices of up to 20, up to 50 and up to 100 US$ t CO 2 -eq. −1 , respectively. In addition, GHG emissions could be reduced by substitution of fossil fuels for energy production by agricultural feedstocks (e.g. crop residues, dung and dedicated energy crops). The economic mitigation potential of biomass energy from agriculture is estimated to be 640, 2240 and 16 000 Mt CO 2 -eq. yr −1 at 0–20, 0–50 and 0–100 US$ t CO 2 -eq. −1 , respectively.


2015 ◽  
Vol 112 (34) ◽  
pp. E4681-E4688 ◽  
Author(s):  
William J. Parton ◽  
Myron P. Gutmann ◽  
Emily R. Merchant ◽  
Melannie D. Hartman ◽  
Paul R. Adler ◽  
...  

The Great Plains region of the United States is an agricultural production center for the global market and, as such, an important source of greenhouse gas (GHG) emissions. This article uses historical agricultural census data and ecosystem models to estimate the magnitude of annual GHG fluxes from all agricultural sources (e.g., cropping, livestock raising, irrigation, fertilizer production, tractor use) in the Great Plains from 1870 to 2000. Here, we show that carbon (C) released during the plow-out of native grasslands was the largest source of GHG emissions before 1930, whereas livestock production, direct energy use, and soil nitrous oxide emissions are currently the largest sources. Climatic factors mediate these emissions, with cool and wet weather promoting C sequestration and hot and dry weather increasing GHG release. This analysis demonstrates the long-term ecosystem consequences of both historical and current agricultural activities, but also indicates that adoption of available alternative management practices could substantially mitigate agricultural GHG fluxes, ranging from a 34% reduction with a 25% adoption rate to as much as complete elimination with possible net sequestration of C when a greater proportion of farmers adopt new agricultural practices.


2018 ◽  
Vol 58 (5) ◽  
pp. 937 ◽  
Author(s):  
K. M. Christie ◽  
R. P. Rawnsley ◽  
C. Phelps ◽  
R. J. Eckard

Every year since 1990, the Australian Federal Government has estimated national greenhouse-gas (GHG) emissions to meet Australia’s reporting commitments under the United National Framework Convention on Climate Change (UNFCCC). The National Greenhouse Gas Inventory (NGGI) methodology used to estimate Australia’s GHG emissions has altered over time, as new research data have been used to improve the inventory emission factors and algorithms, with the latest change occurring in 2015 for the 2013 reporting year. As measuring the GHG emissions on farm is expensive and time-consuming, the dairy industry is reliant on estimating emissions using tools such as the Australian Dairy Carbon Calculator (ADCC). The present study compared the emission profiles of 41 Australian dairy farms with ADCC using the old (pre-2015) and new (post-2015) NGGI methodologies to examine the impact of the changes on the emission intensity across a range of dairy-farm systems. The estimated mean (±s.d.) GHG emission intensity increased by 3.0%, to 1.07 (±0.02) kg of carbon dioxide equivalents per kilogram of fat-and-protein-corrected milk (kg CO2e/kg FPCM). When comparing the emission intensity between the old and new NGGI methodologies at a regional level, the change in emission intensity varied between a 4.6% decrease and 10.4% increase, depending on the region. When comparing the source of emissions between old and new NGGI methodologies across the whole dataset, methane emissions from enteric fermentation and waste management both increased, while nitrous oxide emissions from waste management and nitrogen fertiliser management, CO2 emissions from energy consumption and pre-farm gate (supplementary feed and fertilisers) emissions all declined. Enteric methane remains a high source of emissions and so will remain a focus for mitigation research. However, these changes to the NGGI methodology have highlighted a new ‘hotspot’ in methane from manure management. Researchers and farm managers will have greater need to identify and implement practices on-farm to reduce methane losses to the environment.


2012 ◽  
Vol 52 (11) ◽  
pp. 998 ◽  
Author(s):  
K. M. Christie ◽  
C. J. P. Gourley ◽  
R. P. Rawnsley ◽  
R. J. Eckard ◽  
I. M. Awty

The Australian dairy industry contributes ~1.6% of the nation’s greenhouse gas (GHG) emissions, emitting an estimated 9.3 million tonnes of carbon dioxide equivalents (CO2e) per annum. This study examined 41 contrasting Australian dairy farms for their GHG emissions using the Dairy Greenhouse Gas Abatement Strategies calculator, which incorporates Intergovernmental Panel on Climate Change and Australian inventory methodologies, algorithms and emission factors. Sources of GHG emissions included were pre-farm embedded emissions associated with key farm inputs (i.e. grains and concentrates, forages and fertilisers), CO2 emissions from electricity and fuel consumption, methane emissions from enteric fermentation and animal waste management, and nitrous oxide emissions from animal waste management and nitrogen fertilisers. The estimated mean (±s.d.) GHG emissions intensity was 1.04 ± 0.17 kg CO2 equivalents/kg of fat and protein-corrected milk (kg CO2e/kg FPCM). Enteric methane emissions were found to be approximately half of total farm emissions. Linear regression analysis showed that 95% of the variation in total farm GHG emissions could be explained by annual milk production. While the results of this study suggest that milk production alone could be a suitable surrogate for estimating GHG emissions for national inventory purposes, the GHG emissions intensity of milk production, on an individual farm basis, was shown to vary by over 100% (0.76–1.68 kg CO2e/kg FPCM). It is clear that using a single emissions factor, such as milk production alone, to estimate any given individual farm’s GHG emissions, has the potential to either substantially under- or overestimate individual farms’ GHG emissions.


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