Soil carbon sequestration in grazing systems: managing expectations
Godde, Cécile M. ; Boer, Imke J.M. de; Ermgassen, Erasmus zu; Herrero, Mario ; Middelaar, Corina E. van; Muller, Adrian ; Röös, Elin ; Schader, Christian ; Smith, Pete ; Zanten, Hannah H.E. van; Garnett, Tara - \ 2020
Climatic Change (2020). - ISSN 0165-0009
Cattle - Climate change - Grasslands - Greenhouse gases - Livestock - Soil carbon
Grazing systems emit greenhouse gases, which can, under specific agro-ecological conditions, be partly or entirely offset by soil carbon sequestration. However, any sequestration is time-limited, reversible, and at a global level outweighed by emissions from grazing systems. Thus, grazing systems are globally a net contributor to climate change and the time scale of key processes needs to be factored into any mitigation efforts. Failing to do so leads to unrealistic expectations of soil carbon management in grazing systems as a mitigation strategy. Protecting the large carbon stocks in grazing lands is also essential in order to avoid further climate change from additional CO2 release. Despite the time-limited and reversible nature of soil carbon sequestration in grazing lands, sequestration should be promoted in cases where it delivers environmental and agronomic benefits as well as for its potential, particularly on degraded land, to increase the feasibility of limiting global warming to less than 2 or preferably 1.5 °C. Some peer-reviewed sequestration estimates are of a similar order of magnitude to other food systems mitigation options over a 10–20 years period, such as reducing food loss and waste by 15% or aligning diets with current health related dietary-recommendations. However, caution should be applied to such comparisons since mitigation estimates are associated with large uncertainties and will ultimately depend on the economic cost-benefit relation, feasibility of implementation and time frame considered.
|Role of national fossil fuel comparators in the nominal emission savings through bioenergy under the red-case study in six eu countries
Banja, M. ; Sikkema, R. ; Spijker, E. ; Szendrei, K. - \ 2019
In: European Biomass Conference and Exhibition Proceedings 2019. - ETA-Florence Renewable Energies (European Biomass Conference and Exhibition Proceedings ) - p. 1701 - 1709.
Bioenergy - Climate-effectiveness - Energy transition - Fossil fuel comparator - Greenhouse gases - Life cycle analysis - Sustainability
As part of the energy transition efforts, most bioenergy policies are strongly driven by the ambition to reduce greenhouse gas (GHG) emissions and substitute fossil fuels. The challenge is to properly select the fossil fuel “baseline” comparators for each form of bioenergy for any given national context. Based on existing literature as well as data and experiences gathered within EU co-funded research projects the paper presents the methodological approach for discussing the effect on nominal GHG emissions savings due to bioenergy under RED rules taking into consideration the national fossil fuels comparators. The paper assesses this effect in the 3-bioenergy markets (electricity, heating/cooling and transport) in Finland, Germany, Italy, Lithuania, the Netherlands and Poland. The paper assesses this effect for each sector separately without trying to compare them showing that project-specific and/or national fossil fuels comparators in the calculation of nominal GHG emission savings from bioenergy can have a more stimulating effect than generic EU comparators and the GHG reduction can be more accurately estimated depending on specific conditions in a country. The paper suggests that for including any other effects than CO2 emissions, it is relevant to select appropriate indicators and use adequate comparators, with enough reference data, for those effects.
Comparison of methods to measure methane for use in genetic evaluation of dairy cattle
Garnsworthy, Philip C. ; Difford, Gareth F. ; Bell, Matthew J. ; Bayat, Ali R. ; Huhtanen, Pekka ; Kuhla, Björn ; Lassen, Jan ; Peiren, Nico ; Pszczola, Marcin ; Sorg, Diana ; Visker, Marleen H.P.W. ; Yan, Tianhai - \ 2019
Animals 9 (2019)10. - ISSN 2076-2615
Dairy cows - Environment - Genetic evaluation - Greenhouse gases - Methane
Partners in Expert Working Group WG2 of the COST Action METHAGENE have used several methods for measuring methane output by individual dairy cattle under various environmental conditions. Methods included respiration chambers, the sulphur hexafluoride (SF6) tracer technique, breath sampling during milking or feeding, the GreenFeed system, and the laser methane detector. The aim of the current study was to review and compare the suitability of methods for large-scale measurements of methane output by individual animals, which may be combined with other databases for genetic evaluations. Accuracy, precision and correlation between methods were assessed. Accuracy and precision are important, but data from different sources can be weighted or adjusted when combined if they are suitably correlated with the ‘true’ value. All methods showed high correlations with respiration chambers. Comparisons among alternative methods generally had lower correlations than comparisons with respiration chambers, despite higher numbers of animals and in most cases simultaneous repeated measures per cow per method. Lower correlations could be due to increased variability and imprecision of alternative methods, or maybe different aspects of methane emission are captured using different methods. Results confirm that there is sufficient correlation between methods for measurements from all methods to be combined for international genetic studies and provide a much-needed framework for comparing genetic correlations between methods should these become available.
Irrigation reduces the negative effect of global warming on winter wheat yield and greenhouse gas intensity
Li, Jiazhen ; Dong, Wenxu ; Oenema, Oene ; Chen, Tuo ; Hu, Chunsheng ; Yuan, Haijing ; Zhao, Liying - \ 2019
Science of the Total Environment 646 (2019). - ISSN 0048-9697 - p. 290 - 299.
Global warming potential - Greenhouse gas intensity - Greenhouse gases - Irrigation - Warming - Wheat yield
Global warming may exacerbate drought, decrease crop yield and affect greenhouse gas (GHG) emissions in semi-arid regions. However, the interactive effects of increases in temperature and water availability on winter wheat yield and GHG emissions in semi-arid climates are not well-understood. Here, we report on a two-year field experiment that examined the effects of a mean soil temperature increase of ~2 °C (at 5 cm depth) with and without additional irrigation on wheat yield and GHG emissions. Infrared heaters were placed above the crop canopy at a height of 1.8 m to simulate warming. Fluxes of CH4, CO2 and N2O were measured using closed static chamber technique once per week during the wheat growing seasons. Warming decreased wheat yield by 28% in the relatively dry year of 2015, while supplemental irrigation nullified the warming effect completely. Warming did not alter the wheat yield significantly in the relatively wet year of 2016, but supplemental irrigation with no warming decreased the wheat yield by 25%. Warming increased CO2 emissions by 28% and CH4 uptake by 24% and tended to decrease N2O emissions. Supplemental irrigation increased N2O emissions but had little effect on CO2 emissions and CH4 uptake. Evidently, warming and supplemental irrigation had interactive effects on wheat yield, GHG emissions and GHG emissions intensity. Precision irrigation appears to be a means of simultaneously increasing wheat yield and reducing GHG emissions under warming conditions in semi-arid areas.
The power and pain of market-based carbon policies : a global application to greenhouse gases from ruminant livestock production
Henderson, B. ; Golub, A. ; Pambudi, D. ; Hertel, T. ; Godde, C. ; Herrero, M. ; Cacho, O. ; Gerber, P. - \ 2018
Mitigation and Adaptation Strategies for Global Change 23 (2018)3. - ISSN 1381-2386 - p. 349 - 369.
Carbon policy - Greenhouse gases - Mitigation - Ruminants
The objectives of this research are to assess the greenhouse gas mitigation potential of carbon policies applied to the ruminant livestock sector [inclusive of the major ruminant species—cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), and goats (Capra hircus)]—with particular emphasis on understanding the adjustment challenges posed by such policies. We show that market-based mitigation policies can greatly amplify the mitigation potential identified in marginal abatement cost studies by harnessing powerful market forces such as product substitution and trade. We estimate that a carbon tax of US$20 per metric ton of carbon dioxide (CO2) equivalent emissions could mitigate 626 metric megatons of CO2 equivalent ruminant emissions per year (MtCO2-eq year−1). This policy would also incentivize a restructuring of cattle production, increasing the share of cattle meat coming from the multiproduct dairy sector compared to more emission intensive, single purpose beef sector. The mitigation potential from this simple policy represents an upper bound because it causes ruminant-based food production to fall and is therefore likely to be politically unpopular. In the spirit of the Paris Agreement (UNFCCC 2015), which expresses the ambition of reducing agricultural emissions while protecting food production, we assess a carbon policy that applies both a carbon tax and a subsidy to producers to manage the tradeoff between food production and mitigation. The policy maintains ruminant production and consumption levels in all regions, but for a much lower global emission reduction of 185 MtCO2-eq year−1. This research provides policymakers with a quantitative basis for designing policies that attempt to trade off mitigation effectiveness with producer and consumer welfare.
Soil carbon 4 per mille
Minasny, Budiman ; Malone, Brendan P. ; McBratney, Alex B. ; Angers, Denis A. ; Arrouays, Dominique ; Chambers, Adam ; Chaplot, Vincent ; Chen, Zueng Sang ; Cheng, Kun ; Das, Bhabani S. ; Field, Damien J. ; Gimona, Alessandro ; Hedley, Carolyn B. ; Hong, Suk Young ; Mandal, Biswapati ; Marchant, Ben P. ; Martin, Manuel ; McConkey, Brian G. ; Mulder, Vera Leatitia ; O'Rourke, Sharon ; Richer-de-Forges, Anne C. ; Odeh, Inakwu ; Padarian, José ; Paustian, Keith ; Pan, Genxing ; Poggio, Laura ; Savin, Igor ; Stolbovoy, Vladimir ; Stockmann, Uta ; Sulaeman, Yiyi ; Tsui, Chun Chih ; Vågen, Tor Gunnar ; Wesemael, Bas van; Winowiecki, Leigh - \ 2017
Geoderma 292 (2017). - ISSN 0016-7061 - p. 59 - 86.
Climate change - Greenhouse gases - Soil carbon - Soil carbon sequestration
The ‘4 per mille Soils for Food Security and Climate’ was launched at the COP21 with an aspiration to increase global soil organic matter stocks by 4 per 1000 (or 0.4 %) per year as a compensation for the global emissions of greenhouse gases by anthropogenic sources. This paper surveyed the soil organic carbon (SOC) stock estimates and sequestration potentials from 20 regions in the world (New Zealand, Chile, South Africa, Australia, Tanzania, Indonesia, Kenya, Nigeria, India, China Taiwan, South Korea, China Mainland, United States of America, France, Canada, Belgium, England & Wales, Ireland, Scotland, and Russia). We asked whether the 4 per mille initiative is feasible for the region. The outcomes highlight region specific efforts and scopes for soil carbon sequestration. Reported soil C sequestration rates globally show that under best management practices, 4 per mille or even higher sequestration rates can be accomplished. High C sequestration rates (up to 10 per mille) can be achieved for soils with low initial SOC stock (topsoil less than 30 t C ha− 1), and at the first twenty years after implementation of best management practices. In addition, areas which have reached equilibrium will not be able to further increase their sequestration. We found that most studies on SOC sequestration only consider topsoil (up to 0.3 m depth), as it is considered to be most affected by management techniques. The 4 per mille number was based on a blanket calculation of the whole global soil profile C stock, however the potential to increase SOC is mostly on managed agricultural lands. If we consider 4 per mille in the top 1m of global agricultural soils, SOC sequestration is between 2-3 Gt C year− 1, which effectively offset 20–35% of global anthropogenic greenhouse gas emissions. As a strategy for climate change mitigation, soil carbon sequestration buys time over the next ten to twenty years while other effective sequestration and low carbon technologies become viable. The challenge for cropping farmers is to find disruptive technologies that will further improve soil condition and deliver increased soil carbon. Progress in 4 per mille requires collaboration and communication between scientists, farmers, policy makers, and marketeers.
Highlights from the 2016 joint call for transnational projects
Keulen, H. van; Bunthof, C.J. ; Ní Choncubhair, Órlaith ; Kelly, Raymond - \ 2017
Zwolle : FACCE ERA-GAS - 16 p.
ERA-GAS - FACCE - Greenhouse gases - Agriculture - Silviculture - ERA-NET Cofund - Monitoring - Mitigation - Food security - Climate change
Report of the joint workshop "Smart Mitigation of GHG in livestock production", 29th and 30th November 2016, in Potsdam, Germany
Bunthof, C.J. - \ 2017
FACCE ERA-GAS - 6 p.
FACCE ERA-GAS - Mitigation - Greenhouse gases - GHG - Livestock - Livestock production - GHG emissions - Animal production systems - production technology
FACCE ERA-GAS (ERA-NET Cofund for Monitoring & Mitigation of Greenhouse gases from Agri- and Silvi-culture), together with the ERA-NET SusAn, (Sustainable Animal Production Systems) and ERA-NET ICT-AGRI 2 (Information and Communication Technologies and Robotics for Sustainable Agriculture) organized a joint workshop on 29-30 November in Potsdam to identify promising approaches to reduce GHG emissions in livestock production. The joint workshop, the first of its kind involving three ERA-NETs, had close to 70 participants from 22 different countries. The three ERA-NETs have already identified a number of potential areas of synergy. This workshop explored one of those areas in detail: Comparison of animal production systems with respect to GHGs. Particular attention was paid to the following two sub-topics: (1) Production technology and management (e.g. housing systems; optimal field and grazing management), and (2) Breeding, physiology, feed & nutrition.The outputs of the workshop will help to set the research priorities for future joint calls and other activities between the three ERA-NETs.
Trade-offs in soil fertility management on arable farms
Bos, Jules F.F.P. ; Berge, Hein F.M. ten; Verhagen, Jan ; Ittersum, Martin K. van - \ 2017
Agricultural Systems 157 (2017). - ISSN 0308-521X - p. 292 - 302.
Carbon sequestration - Climate change mitigation - Greenhouse gases - Linear programming - Nitrogen losses
Crop production and soil fertility management implies a multitude of decisions and activities on crop choice, rotation design and nutrient management. In practice, the choices to be made and the resulting outcomes are subject to a wide range of objectives and constraints. Objectives are economic as well as environmental, for instance sequestering carbon in agricultural soils or reducing nitrogen losses. Constraints originate from biophysical and institutional conditions that may restrict the possibilities for choosing crops or using specific cultivation and fertilization practices. To explore the consequences of management interventions to increase the supply of organic C to the soil on income and N losses, we developed the linear programming model NutMatch. The novelty of the model is the coherent description of mutual interdependencies amongst a broad range of sustainability indicators related to soil fertility management in arable cropping, enabling the quantification of synergies and trade-offs between objectives. NutMatch was applied to four different crop rotations subjected to four fertiliser strategies differing in the use of the organic fertilisers cattle slurry, pig slurry or compost, next to mineral fertiliser. Each combination of rotation and fertiliser strategy contributed differently to financial return, N emissions and organic matter inputs into the soil.Our model calculations show that, at the rotational level, crop residues, cattle slurry and compost each substantially contributed to SOC accumulation (range 200-450 kg C ha-1 yr-1), while contributions of pig slurry and cover crops were small (20-50 kg C ha-1 yr-1). The use of compost and pig slurry resulted in increases of 0.61-0.73 and 3.15-3.38 kg N2O-N per 100 kg extra SOC accumulated, respectively, with the other fertilizers taking an intermediate position. From a GHG emission perspective, the maximum acceptable increase is 0.75 kg N2O-N per 100 kg extra SOC accumulated, which was only met by compost. Doubling the winter wheat area combined with the cultivation of cover crops to increase SOC accumulation resulted in a net GHG emission benefit, but was associated with a financial trade-off of 2.30-3.30 euro per kg SOC gained.Our model calculations suggest that trade-offs between C inputs and emissions of greenhouse gases (notably N2O) or other pollutants (NO3, NH3) can be substantial. Due to the many data from a large variety of sources incorporated in the model, the trade-offs are uncertain. Our model-based explorations provide insight in soil carbon sequestration options and their limitations vis-a-vis other objectives.
Direct nitrous oxide emissions in Mediterranean climate cropping systems : Emission factors based on a meta-analysis of available measurement data
Cayuela, Maria L. ; Aguilera, Eduardo ; Sanz-Cobena, Alberto ; Adams, Dean C. ; Abalos Rodriguez, Diego ; Barton, Louise ; Ryals, Rebecca ; Silver, Whendee L. ; Alfaro, Marta A. ; Pappa, Valentini A. ; Bouwman, Lex ; Lassaletta, Luis - \ 2017
Agriculture, Ecosystems and Environment 238 (2017). - ISSN 0167-8809 - p. 25 - 35.
Field studies - Greenhouse gases - Mitigation - NO - Systematic review
Many recent reviews and meta-analyses of N2O emissions do not include data from Mediterranean studies. In this paper we present a meta-analysis of the N2O emissions from Mediterranean cropping systems, and propose a more robust and reliable regional emission factor (EF) for N2O, distinguishing the effects of water management, crop type, and fertilizer management. The average overall EF for Mediterranean agriculture (EFMed) was 0.5%, which is substantially lower than the IPCC default value of 1%. Soil properties had no significant effect on EFs for N2O. Increasing the N fertilizer rate led to higher EFs; when N was applied at rates greater than 400kgNha-1, the EF did not significantly differ from the 1% default value (EF: 0.82%). Liquid slurries led to emissions that did not significantly differ from 1%; the other fertilizer types were lower but did not significantly differ from each other. Rain-fed crops in Mediterranean regions have lower EFs (EF: 0.27%) than irrigated crops (EF: 0.63%). Drip irrigation systems (EF: 0.51%) had 44% lower EF than sprinkler irrigation methods (EF: 0.91%). Extensive crops, such as winter cereals (wheat, oat and barley), had lower EFs (EF: 0.26%) than intensive crops such as maize (EF: 0.83%). For flooded rice, anaerobic conditions likely led to complete denitrification and low EFs (EF: 0.19%). Our results indicate that N2O emissions from Mediterranean agriculture are overestimated in current national greenhouse gas inventories and that, with the new EF determined from this study, the effect of mitigation strategies such as drip irrigation or the use of nitrification inhibitors, even if highly significant, may be smaller in absolute terms.
|Improving the sustainability of fatty acid methyl esters (Fame – biodiesel) – assessment of options for industry and agriculture
Jungmeier, G. ; Pucker, J. ; Ernst, M. ; Haselbacher, P. ; Lesschen, J.P. ; Kraft, A. ; Schulzke, T. ; Loo, E.N. van - \ 2016
- p. 1766 - 1769.
Biodiesel - Greenhouse gases - Sustainability - SWOT analyses - Vegetable oils
The life cycle based greenhouse gas (GHG) balances of Fatty Acid Methyl Esters (FAME also called “Biodiesel”) from various resources have been set in the Renewable Energy Directive (RED). Due to technology and scientific progress there are various options to improve the GHG balances of FAME. In this Supporting Action 10 most interesting options were assessed: 1) “Biomethanol”: Substitution of fossil methanol with biomethanol; 2) “Bioethanol”: Substitution of fossil methanol with bioethanol; 3) “CHP residues”: Use of residues and co-products in an CHP plant; 4) “New plant species”: Examination of new plants for vegetable oils, that could increase the biomass weight without any detrimental effect on the oil seed; 5) “Bioplastics and biochemicals”: Production of bioplastics and biochemicals from process residues; 6) “Advanced agriculture”: Advanced agricultural practices in terms of N2O emissions and soil carbon accumulation; 7) “Organic residues”: Use of organic versus mineral fertilizer for feedstock cultivation; 8) “FAME as fuel”: Use of FAME in machinery for cultivation, transportation and distribution; 9) “Retrofitting multi feedstock”: Retrofitting of single feedstock plants for blending fatty residues; and 10) “Green electricity”: Use of renewable electricity produced in a PV plant on site. The assessment approach started with the GHG standard values of the RED and the corresponding background data documented in BioGrace. For the most relevant FAME production possibilities in Europe, characterized by the feedstock (rapeseed, sunflower, palm oil, soybean, used cooking oil, animal fat) and FAME production capacity (50 - 200 kt/a), the technical and economic data of “Best Available Technology in 2015” (BAT) were used as starting point to assess the improvement options. Based on the calculation of GHG emissions (g CO2-eq/MJ) and production cost (€/tFAME) an overall assessment (incl SWOT-Analyses and Stakeholder involvement) of the options was made and summarized in “Fact Sheets”. A significant GHG reduction compared to the RED values in processing is possible, if best available technology (BAT) is applied. The GHG emissions of cultivation compared to RED are higher due to improved data on the correlation between fertilizer input and yields. The assessed GHG improvements options show that the potential to reduce emissions is relatively large in agriculture cultivation, but a relatively low in processing. The production cost analysis shows that revenues from co-produced animal feed and oil yield per hectare have a strong influence on total production costs, e.g. mainly animal feed from soybeans. The total FAME production cost of BAT are 280 – 1,000 €/tFAME, including revenues from co-products. Cost ranges arise due to different feedstock and capacities. The greenhouse gas analysis of the improvement options results in a GHG reduction potential of 0 - 37 g CO2-eq/MJ compared to BAT. The greenhouse gas mitigation costs of improvement options range between -260 and +1,000 €/t CO2-eq. Options with negative greenhouse gas mitigation costs generate economic benefits compared to the base case. Summing up the assessment one can conclude that the future FAME production has several options to further improve its GHG balance thus contributing substantially to a more sustainable transportation sector.