Impact of dietary manipulation on nutrient flows and greenhouse gas emissions in cattle

The growing global demand for meat and particularly in countries such as Brazil is expected to increase intensive animal production. Consequently the main pollutants of interest are nitrogen (N), phosphorus (P) and greenhouse gases (GHG). Nitrogen can be a problem through nitrate leaching to water bodies, ammonia, and nitrous oxide emissions to air. Phosphorus loading in soil from manure application can be the main issue due to the tendency of P to accumulate in soil and leach to groundwater and rivers. The sources of agricultural GHG emissions include methane from enteric fermentation, manure storage and spreading, and nitrous oxide mainly from application of manure on land. Dietary manipulation has proven to be an effective tool to reduce nutrient/mineral pollution and GHG emissions. Several studies have shown that decreasing crude protein in the diet could reduce N excretion and ammonia volatilization substantially without compromising productivity. Similarly, reducing P intake in dairy cattle has been shown to reduce P excretion by up to 10%. Changing the type of N and P consumed and energy level of diet has also been reported to affect the amount and type of N and P excreted. Dietary manipulation also has an impact on the amount of GHG emissions, particularly, from enteric fermentation. Feeding cattle with a high starch and low fiber diet, for example, reduces acetate production in the rumen, and leads to lower methane production. Emissions from stored manure from high fiber fed animals tend to be higher. Evidence is also available that diet affects emissions from manure applied soil. As level of production is increased to meet global demand for ruminant meat and milk products, dietary manipulation will be useful in addressing environmental concerns.

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Greenhouse gas emissions from the water–air interface of a grassland river: a case study of the Xilin River

Scientific Reports ◽

10.1038/s41598-021-81658-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xue Hao ◽

Yu Ruihong ◽

Zhang Zhuangzhuang ◽

Qi Zhen ◽

Lu Xixi ◽

...

Keyword(s):

Carbon Dioxide ◽

Land Use ◽

Nitrous Oxide ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Ghg Emissions ◽

Nitrous Oxide Emissions ◽

Gas Emissions ◽

Sand Land ◽

Very High

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.

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Effects of strategic tillage on short-term erosion, nutrient loss in runoff and greenhouse gas emissions

Soil Research ◽

10.1071/sr16136 ◽

2017 ◽

Vol 55 (3) ◽

pp. 201 ◽

Cited By ~ 16

Author(s):

A. R. Melland ◽

D. L. Antille ◽

Y. P. Dang

Keyword(s):

Nitrous Oxide ◽

Greenhouse Gas ◽

Heavy Rainfall ◽

Ghg Emissions ◽

Nutrient Loss ◽

Nitrous Oxide Emissions ◽

Nutrient Losses ◽

Short Term ◽

Trade Offs ◽

Carbon Dioxide Co2

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.

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Efficient ruminant production from grassland

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200030878 ◽

2009 ◽

Vol 2009 ◽

pp. 248-248

Author(s):

N D Scollan ◽

J Moorby

Keyword(s):

Nitrous Oxide ◽

Production Efficiency ◽

Anthropogenic Sources ◽

Nitrous Oxide Emissions ◽

Increase Production Efficiency ◽

Plant Nitrogen ◽

Rumen Microbes ◽

Ruminant Meat ◽

Choice Of Species ◽

The Uk

Ruminant production in the UK is largely dependent on grasslands: approximately 52% of UK land is (improved) grassland and rough grazing. Herbage production from improved grassland can be over five times higher than that of indigenous swards (Davies et al., 1984) and these pastures account for the majority of ruminant (meat and milk) production from grassland the UK. They are also amenable to manipulation through the choice of species, variety and mixture of forages sown. Efficiency of production can be influenced at the levels of both the plant and the animal and by the nutrition and genetics of both. This paper examines strategies to increase production efficiency based upon optimising rumen fermentation linked to plant breeding approaches. In this way efficiency can be improved without recourse to diet manipulation with supplements, which is generally impractical at grazing. Although the rumen microbial population allows the ruminant animal to extract energy from otherwise unusable sources (i.e. fibres), the rumen is also the source of greatest inefficiencies in the use of nitrogen and energy. Degraded plant nitrogen that is not captured by the rumen microbes tends to be absorbed as ammonia, much of which is excreted as urea and contributes to ammonia and nitrous oxide emissions. Similarly, methane release from the rumen represents a waste of energy that could otherwise be used for production. Globally, these two processes result in ruminant livestock accounting for approximately a third of the methane emissions (Beauchemin et al., 2008) and half of the nitrous oxide emissions (de Klein and Eckard, 2008) from anthropogenic sources.

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Greenhouse gas inventory of agriculture in the Czech Republic

Plant Soil and Environment ◽

10.17221/2528-pse ◽

2009 ◽

Vol 55 (No. 8) ◽

pp. 311-319 ◽

Cited By ~ 1

Author(s):

Z. Exnerová ◽

E. Cienciala

Keyword(s):

Czech Republic ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Agricultural Sector ◽

Agricultural Soils ◽

Ghg Emissions ◽

Nitrous Oxide Emissions ◽

Enteric Fermentation ◽

Gas Emissions ◽

The Czech Republic

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.

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ESTIMATION OF NITROUS OXIDE EMISSIONS FROM AGRICULTURAL SOILS IN VOIVODESHIPS IN POLAND

Annals of the Polish Association of Agricultural and Agribusiness Economists ◽

10.5604/01.3001.0014.5616 ◽

2020 ◽

Vol XXII (4) ◽

pp. 94-104

Author(s):

Anna Jędrejek

Keyword(s):

Nitrous Oxide ◽

Winter Wheat ◽

Agricultural Soils ◽

Ghg Emissions ◽

Organic Content ◽

Nitrous Oxide Emissions ◽

Regional Differentiation ◽

N2o Emissions ◽

Winter Rape ◽

Winter Triticale

The purpose of this study was to estimate nitrogen oxide emissions from soils used for agricultural purposes by voivodships. Compared N2O emissions were estimated according to the recommended IPCC (tier 1) method with simulated emissions using the DNDC (tier 3) model. Analyses were done for crop rotation (winter rape, winter wheat, winter wheat, winter triticale) in four cropping systems. Moreover, simulated N2O emissions from winter rape and winter triticale cultivation showed lower emissions and constituted 1475% and 13-76% of IPCC estimated emissions, respectively. The use of the model also enabled the determination of factors, which have an impact on nitrous oxide emissions and define its regional differentiation. The analysis showed that with increasing initial soil organic content, emissions of N2O rise and decrease with increasing precipitation or carbon sequestration. Considering the requirements for reduction GHG emissions, improving the methodology used in estimating nitrous oxide emissions is of significant practical value.

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Soil Management Practices to Mitigate Nitrous Oxide Emissions and Inform Emission Factors in Arid Irrigated Specialty Crop Systems

Soil Systems ◽

10.3390/soilsystems3040076 ◽

2019 ◽

Vol 3 (4) ◽

pp. 76

Author(s):

Xia Zhu-Barker ◽

Mark Easter ◽

Amy Swan ◽

Mary Carlson ◽

Lucas Thompson ◽

...

Keyword(s):

Nitrous Oxide ◽

Crop Production ◽

Management Practices ◽

Ghg Emissions ◽

Soil Management ◽

Emission Factors ◽

Nitrous Oxide Emissions ◽

Specialty Crops ◽

Specialty Crop ◽

The Impact

Greenhouse gas (GHG) emissions from arid irrigated agricultural soil in California have been predicted to represent 8% of the state’s total GHG emissions. Although specialty crops compose the majority of the state’s crops in both economic value and land area, the portion of GHG emissions contributed by them is still highly uncertain. Current and emerging soil management practices affect the mitigation of those emissions. Herein, we review the scientific literature on the impact of soil management practices in California specialty crop systems on GHG nitrous oxide emissions. As such studies from most major specialty crop systems in California are limited, we focus on two annual and two perennial crops with the most data from the state: tomato, lettuce, wine grapes and almond. Nitrous oxide emission factors were developed and compared to Intergovernmental Panel on Climate Change (IPCC) emission factors, and state-wide emissions for these four crops were calculated for specific soil management practices. Dependent on crop systems and specific management practices, the emission factors developed in this study were either higher, lower or comparable to IPCC emission factors. Uncertainties caused by low gas sampling frequency in these studies were identified and discussed. These uncertainties can be remediated by robust and standardized estimates of nitrous oxide emissions from changes in soil management practices in California specialty crop systems. Promising practices to reduce nitrous oxide emissions and meet crop production goals, pertinent gaps in knowledge on this topic and limitations of this approach are discussed.

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Potential solutions to the major greenhouse-gas issues facing Australasian dairy farming

Animal Production Science ◽

10.1071/an18574 ◽

2020 ◽

Vol 60 (1) ◽

pp. 10 ◽

Cited By ~ 2

Author(s):

R. J. Eckard ◽

H. Clark

Keyword(s):

Nitrous Oxide ◽

Carbon Sequestration ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Production Efficiency ◽

Dairy Industry ◽

Ghg Emissions ◽

Nitrous Oxide Emissions ◽

Organic Carbon Content ◽

On Farm

The Australasian dairy industry is facing the dual challenges of increasing productivity, while also reducing its emissions of the greenhouse gases (GHG) methane and nitrous oxide. Following the COP21 Paris Agreement, all sectors of the economy will be expected to contribute to GHG abatement. Enteric methane is the major source of GHG emissions from dairy production systems (>70%), followed by nitrous oxide (13%) and methane (12%) from animal waste, with nitrogen (N)-fertiliser use contributing ~3.5% of total on-farm non-carbon dioxide equivalent (non-CO2e) emissions. Research on reducing methane emissions from dairy cattle has focussed on feeding dietary supplements (e.g. tannins, dietary oils and wheat), rumen modification (e.g. vaccine, inhibitors), breeding and animal management. Research on reducing nitrous oxide emissions has focussed on improving N fertiliser efficiency and reducing urinary N loss. Profitable options for significant abatement on farm are still limited, with the industry focusing instead on improving production efficiency, while reducing emission intensity (t CO2e/t product). Absolute emission reduction will become an imperative as the world moves towards carbon neutrality by 2050 and, thus, a priority for research. However, even with implementation of best-practice abatement, it is likely that some residual emissions will remain in the foreseeable future. The soil organic carbon content of dairy soils under well fertilised, high-rainfall or irrigated permanent pastures are already high, therefore limiting the potential for further soil carbon sequestration as an offset against these residual emissions. The Australasian dairy industry will, therefore, also need to consider how these residual emissions will be offset through carbon sequestration mainly in trees and, to a more limited extent, increasing soil organic carbon.

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Contribution of nitrous oxide emissions from wastewater treatment to carbon accounting

Journal of Water and Climate Change ◽

10.2166/wcc.2012.014 ◽

2012 ◽

Vol 3 (2) ◽

pp. 95-109 ◽

Cited By ~ 4

Author(s):

P. Winter ◽

P. Pearce ◽

K. Colquhoun

Keyword(s):

Nitrous Oxide ◽

Wastewater Treatment ◽

Large Scale ◽

Ventilation System ◽

Ghg Emissions ◽

Treatment Plant ◽

Carbon Accounting ◽

High Rate ◽

Nitrous Oxide Emissions ◽

N2o Emissions

This paper describes research that investigated the contribution of nitrous oxide (N2O) emissions from wastewater treatment to the greenhouse gas emissions of a wastewater treatment plant (WWTP). The research provided several months of robust data from a large-scale WWTP serving a population equivalent of 284,000. N2O emissions were monitored online at the ventilation system of a covered activated sludge (AS) plant, therefore capturing the complete off-gas stream. This methodology eliminated errors incurred through sampling of small percentages of emission areas and allowed representative continuous measurements. Nitrogen load and dissolved oxygen (DO) were also monitored. To address seasonal variation, data were recorded in two extensive phases. In addition, three separate 24-hour surveys were conducted. Emissions of CO2, CH4 and N2O associated with treatment were calculated using the UK Water Industry Research carbon accounting workbook. This study measured N2O emissions from the AS process (nitrification and denitrification) equivalent to 17.5% of the annual GHG emissions (tonnes CO2e) from processes at the WWTP. The emissions were within the range of published N2O emissions. The diurnal profiles confirmed literature findings of a trend of increased N2O emissions when the DO decreased. The DO in the high rate zone of the aeration lanes should be kept above 1 mg l−1 to avoid favourable conditions for N2O emissions during nitrification.

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Revised greenhouse-gas emissions from Australian dairy farms following application of updated methodology

Animal Production Science ◽

10.1071/an16286 ◽

2018 ◽

Vol 58 (5) ◽

pp. 937 ◽

Cited By ~ 1

Author(s):

K. M. Christie ◽

R. P. Rawnsley ◽

C. Phelps ◽

R. J. Eckard

Keyword(s):

Waste Management ◽

Greenhouse Gas ◽

Emission Intensity ◽

Ghg Emissions ◽

Dairy Farm ◽

Dairy Farms ◽

Nitrous Oxide Emissions ◽

Enteric Fermentation ◽

On Farm ◽

The Impact

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.

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Opportunities for reducing environmental emissions from forage-based dairy farms

Agricultural and Food Science ◽

10.23986/afsci.6702 ◽

2013 ◽

Vol 22 (1) ◽

pp. 93-107 ◽

Cited By ~ 12

Author(s):

Tom Misselbrook ◽

Agustin Del Prado ◽

David Chadwick

Keyword(s):

Nitrous Oxide ◽

Methane Emissions ◽

Mitigation Strategies ◽

Mitigation Measures ◽

Scale Model ◽

Nitrous Oxide Emissions ◽

Manure Management ◽

Nitrification Inhibitors ◽

Forage Crops ◽

Enteric Fermentation

Modern dairy production is inevitably associated with impacts to the environment and the challenge for the industry today is to increase production to meet growing global demand while minimising emissions to the environment. Negative environmental impacts include gaseous emissions to the atmosphere, of ammonia from livestock manure and fertiliser use, of methane from enteric fermentation and manure management, and of nitrous oxide from nitrogen applications to soils and from manure management. Emissions to water include nitrate, ammonium, phosphorus, sediment, pathogens and organic matter, deriving from nutrient applications to forage crops and/or the management of grazing livestock. This paper reviews the sources and impacts of such emissions in the context of a forage-based dairy farm and considers a number of potential mitigation strategies, giving some examples using the farm-scale model SIMSDAIRY. Most of the mitigation measures discussed are associated with systemic improvements in the efficiency of production in dairy systems. Important examples of mitigations include: improvements to dairy herd fertility, that can reduce methane and ammonia emissions by up to 24 and 17%, respectively; diet modification such as the use of high sugar grasses for grazing, which are associated with reductions in cattle N excretion of up to 20% (and therefore lower N losses to the environment) and potentially lower methane emissions, or reducing the crude protein content of the dairy cow diet through use of maize silage to reduce N excretion and methane emissions; the use of nitrification inhibitors with fertiliser and slurry applications to reduce nitrous oxide emissions and nitrate leaching by up to 50%. Much can also be achieved through attention to the quantity, timing and method of application of nutrients to forage crops and utilising advances made through genetic improvements.

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