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Benefits and trade-offs of replacing synthetic fertilizers by animal manures in crop production in China: A meta-analysis
Zhang, Xiaoying ; Fang, Qunchao ; Zhang, Tao ; Ma, Wenqi ; Velthof, Gerard L. ; Hou, Yong ; Oenema, Oene ; Zhang, Fusuo - \ 2020
Global Change Biology 26 (2020)2. - ISSN 1354-1013 - p. 888 - 900.
ammonia emissions - crop yield - fertilizers - greenhouse gases - livestock manure - meta-analysis - soil type - trade-offs
Recycling of livestock manure to agricultural land may reduce the use of synthetic fertilizer and thereby enhance the sustainability of food production. However, the effects of substitution of fertilizer by manure on crop yield, nitrogen use efficiency (NUE), and emissions of ammonia (NH3), nitrous oxide (N2O) and methane (CH4) as function of soil and manure properties, experimental duration and application strategies have not been quantified systematically and convincingly yet. Here, we present a meta-analysis of these effects using results of 143 published studies in China. Results indicate that the partial substitution of synthetic fertilizers by manure significantly increased the yield by 6.6% and 3.3% for upland crop and paddy rice, respectively, but full substitution significantly decreased yields (by 9.6% and 4.1%). The response of crop yields to manure substitution varied with soil pH and experimental durations, with relatively large positive responses in acidic soils and long-term experiments. NUE increased significantly at a moderate ratio (<40%) of substitution. NH3 emissions were significantly lower with full substitution (62%–77%), but not with partial substitution. Emissions of CH4 from paddy rice significantly increased with substitution ratio (SR), and varied by application rates and manure types, but N2O emissions decreased. The SR did not significantly influence N2O emissions from upland soils, and a relative scarcity of data on certain manure characteristic was found to hamper identification of the mechanisms. We derived overall mean N2O emission factors (EF) of 0.56% and 0.17%, as well as NH3 EFs of 11.1% and 6.5% for the manure N applied to upland and paddy soils, respectively. Our study shows that partial substitution of fertilizer by manure can increase crop yields, and decrease emissions of NH3 and N2O, but depending on site-specific conditions. Manure addition to paddy rice soils is recommended only if abatement strategies for CH4 emissions are also implemented.
Entry Points for Reduction of Greenhouse Gas Emissions in Small-Scale Dairy Farms: Looking Beyond Milk Yield Increase
Vries, Marion de; Zahra, Windi Al ; Wouters, Adriaan P. ; Middelaar, Corina E. van; Oosting, Simon J. ; Tiesnamurti, Bess ; Vellinga, Theun V. - \ 2019
Frontiers in Sustainable Food Systems 3 (2019). - ISSN 2571-581X
climate change mitigation - dairy cattle - feeding - greenhouse gases - manure management
Increasing milk yield per cow is considered a promising climate change mitigation strategy for small-scale dairy farms in developing countries. As it can be difficult to increase cow productivity, mitigation options beyond this production strategy need to be identified. The aim of this study was to identify entry points for mitigation of GHG emissions in small-scale dairy farms in Lembang Sub-district, West Java, Indonesia. Data on herd composition, productivity, feeding, and manure management were collected in a survey of 300 randomly selected dairy farms. Characteristics of farms with the 25% lowest (<3291 kg milk/cow/y), medium 50% (3291–4975 kg milk/cow/y), and 25% highest milk yields (≥4976 kg milk/cow/y) were compared. Life cycle assessment was then performed to estimate the cradle-to-farm gate GHG emission intensity (EI) of farms. The relationship between EI and milk yield per cow for all farms was modeled and farms with an EI below and above their predicted EI were compared (“low” and “high” EI farms). Results showed that milk yield explained 57% of the variance in EI among farms. Farms with medium and high milk yields were more often specialized farms, fed more tofu waste and compound feed, and had higher feed costs than farms with low milk yields (P < 0.05). Farms with high milk yields also applied less manure on farm land than farms with low milk yields (P < 0.05). Low EI farms had fewer cows, and fed less rice straw, more cassava waste, and more compound concentrate feed (particularly the type of concentrates consisting largely of by-products from milling industries) than high EI farms (P < 0.05). In addition, low EI farms discharged more manure, stored less solid manure, used less manure for anaerobic digestion followed by daily spreading, and applied less manure N on farmland than high EI farms (P < 0.05). Some associations were affected by confounding factors. Farm management factors associated with milk yield and the residual variation in EI were considered potential entry points for GHG mitigation. Feeding less rice straw and discharging manure, however, were considered unsuitable mitigation strategies because of expected trade-offs with other environmental issues or negative impacts on food-feed competition.
What to do about the growing carbon emissions of tourism?
Pellis, A. - \ 2019
Wageningen : WURcast
pollution by tourism - carbon dioxide - greenhouse gases - international travel - airplanes
Ontstening van tuinen
Spijker, J.H. - \ 2018
greening - urban planning - urban areas - water holding capacity - water harvesting - heat stability - biodiversity - gardens - greenhouse gases - public green areas
Dit gastcollege gaat over het belang van groene tuinen in het licht van de uitdagingen van de stad
Lesmateriaal over “Duurzame melkveehouderij” voor MBO
Plomp, M. ; Doornewaard, G.J. ; Zijlstra, J. - \ 2018
Wageningen : Wageningen Livestock Research - 19 p.
animal welfare - teaching materials - animal production - intermediate vocational training - sustainability - greenhouse gases - ammonia - biodiversity - minerals - cycling
Deze bundel is gemaakt binnen het project ‘Ondersteuning CIV Melkveehouderij – 2018’ onder verantwoordelijkheid van Wageningen Research. De productie ervan is mede mogelijk gemaakt door de financiering van het project vanuit de WURKS-regeling.
Extreme drought boosts CO2 and CH4 emissions from reservoir drawdown areas
Kosten, Sarian ; Berg, Sanne van den; Mendonça, Raquel ; Paranaíba, José R. ; Roland, Fabio ; Sobek, Sebastian ; Hoek, Jamon Van Den; Barros, Nathan - \ 2018
Inland Waters : Journal of the International Society of Limnology 8 (2018)3. - ISSN 2044-2041 - p. 329 - 340.
drought - emission peaks - greenhouse gases - reservoirs - rewetting - sediment
Although previous studies suggest that greenhouse gas (GHG) emissions from reservoir sediment exposed to the atmosphere during drought may be substantial, this process has not been rigorously quantified. Here we determined carbon dioxide (CO2) and methane (CH4) emissions from sediment cores exposed to a drying and rewetting cycle. We found a strong temporal variation in GHG emissions with peaks when the sediment was drained (C emissions from permanently wet sediment and drained sediments were, respectively, 251 and 1646 mg m−2 d−1 for CO2 and 0.8 and 547.4 mg m−2 d−1 for CH4) and then again during rewetting (C emissions from permanently wet sediment and rewetted sediments were, respectively, 456 and 1725mg m−2 d−1 for CO2 and 1.3 and 3.1 mg m−2 d−1 for CH4). To gain insight into the importance of these emissions at a regional scale, we used Landsat satellite imagery to upscale our results to all Brazilian reservoirs. We found that during the extreme drought of 2014–2015, an additional 1299 km2 of sediment was exposed, resulting in an estimated emission of 8.5 × 1011 g of CO2-eq during the first 15 d after the overlying water disappeared and in the first 33 d after rewetting, the same order of magnitude as the year-round GHG emissions of large (∼mean surface water area 454 km2) Brazilian reservoirs, excluding the emissions from the draw-down zone. Our estimate, however, has high uncertainty, with actual emissions likely higher. We therefore argue that the effects of drought on reservoir GHG emissions merits further study, especially because climate models indicate an increase in the frequency of severe droughts in the future. We recommend incorporation of emissions during drying and rewetting into GHG budgets of reservoirs to improve regional GHG emission estimates and to enable comparison between GHG emissions from hydroelectric and other electricity sources. We also emphasize that peak emissions at the onset of drought and the later rewetting should be quantified to obtain reliable emission estimates.
Effect verandering landgebruik op emissies broeikasgassen
Vellinga, T. ; Eekeren, N. van - \ 2017
V-focus 14 (2017)2. - ISSN 1574-1575 - p. 38 - 39.
landgebruik - bodemkwaliteit - broeikasgassen - emissie - melkveehouderij - graslanden - wisselbouw - grasklaver - land use - soil quality - greenhouse gases - emission - dairy farming - grasslands - ley farming - grass-clover swards
In het vorige nummer van V-focus is besproken wat het optimale landgebruik voor bodemkwaliteit is op melkveebedrijven met gras en mais, namelijk: 60% blijvend grasland met een lage frequentie van graslandvernieuwing en 20% grasklaver (rode en witte klaver) in rotatie met 20% bouwland. In het hetzelfde nummerwerd uitgerekend dat dit een gemiddeld melkveebedrijf 7.000 euro per jaar oplevert. In het Project Vruchtbare Kringloop Achterhoek en Liemers (VKA) is gekeken wat dit betekent voor de emissie van broeikasgassen. In de kennisgroep Melk&Klimaat van VKA werken melkveehouders, samen met FrieslandCampina, aan het verminderen van de ‘carbonfootprint’ van melk
Greenhouse gas reporting for the LULUCF sector in the Netherlands : methodological background, update 2016
Arets, E.J.M.M. ; Kolk, J.W.H. van der; Hengeveld, G.M. ; Lesschen, J.P. ; Kramer, H. ; Kuikman, P.J. ; Schelhaas, M.J. - \ 2017
Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 89) - 90
greenhouse gases - methodology - emission - netherlands - broeikasgassen - methodologie - emissie - nederland
This report provides a complete methodological description and background information of the DutchNational System for Greenhouse gas Reporting of the LULUCF sector. It provides detailed description of themethodologies, activity data and emission factors that were used. Additionally it gives a table-by-tableelaboration of the choices and motivations for filling the CRF tables for KP-LULUCF
Paprikateelt in de hooggeïsoleerde VenLow Energy kas
Zwart, H.F. de; Gelder, A. de; Hofland-Zijlstra, J. ; Noordam, M. - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1435) - 34
paprika's - capsicum annuum - kassen - kasgewassen - glasgroenten - glastuinbouw - energiebesparing - energiegebruik - isolatie (insulation) - broeikasgassen - kooldioxide - sweet peppers - capsicum annuum - greenhouses - greenhouse crops - greenhouse vegetables - greenhouse horticulture - energy saving - energy consumption - insulation - greenhouse gases - carbon dioxide
In order to realise a horticultural sector that operates without the combustion of fossil fuel, the first step is to reduce the demand for heating by improving the insultation of greenhouses. This holds especially for crops that are grown at high temperatures, like sweet pepper. The Venlow Energy greenhouse with its double glass cladding and energy screen is a good example of such a highly insulated greenhouse. This report presents the results of a one year cultivation and serves as a bench mark for the state of the art in energy conserving production of Sweet Pepper in the Netherlands. It shows the greenhouse climate conditions required, and the possibilities to meet these requirements with a low energy consumption and options to realise this from sustainable sources. The application of sustainable energy sources was not tested in practice, but since the exact resources (heat and CO2) required from hour to hour were measured, it is easy to do the math on the amounts and capacities needed. The application of pure CO2 or CO2 from another sustainable source is essential when aiming at a fossil energy free horticulture. Without external CO2 the production will drop substantially, especially because an energy conserving greenhouse has typically a strongly reduced air exchange. But, for the same reason, the amount of CO2 needed to increase the CO2 concentration is quite limited, 25 kg/m² per year in this experiment. With a production of 32.5 kg class I of red Sweet Pepper per m², the experiment has shown that halving the energy consumption compared to the general practice did’nt reduced the production.
Improving environmental sustainability of palm oil production in Thailand
Saswattecha, Kanokwam - \ 2017
Wageningen University. Promotor(en): Carolien Kroeze; Lars Hein. - Wageningen : Wageningen University - ISBN 9789463430401 - 277
palm oils - sustainability - environmental protection - environmental management - environmental impact - greenhouse gases - emission - thailand - palmoliën - duurzaamheid (sustainability) - milieubescherming - milieubeheer - milieueffect - broeikasgassen - emissie - thailand
Demand for palm oil in Thailand has increased as a result of Thai policies promoting the use of biodiesel. This increased demand results in negative effects on ecosystem services and increases environment pollution. Most existing studies focus on global warming impact alone, while other environmental impacts are being overlooked. Moreover, several mitigation options are widely studied but none of them has been investigated for cost-effectiveness. Such information is crucial for decision makers to explore possibilities for improving environmental performance towards sustainable palm oil production in Thailand. Therefore, this thesis aimed to analyse environmental impacts in the past and future, and to explore possibilities for improving environmental sustainability of the palm oil sector in Thailand. These objectives have been met through an integrated environmental assessment by coupling a landscape model and sectoral model which can be seen as the novelty of this thesis.
Invited review : Phenotypes to genetically reduce greenhouse gas emissions in dairying
Haas, Y. de; Pszczola, M. ; Soyeurt, H. ; Wall, E. ; Lassen, J. - \ 2017
Journal of Dairy Science 100 (2017)2. - ISSN 0022-0302 - p. 855 - 870.
dairy cattle - enteric methane - environmental phenotypes - genomic selection - greenhouse gases
Phenotypes have been reviewed to select for lower-emitting animals in order to decrease the environmental footprint of dairy cattle products. This includes direct selection for breath measurements, as well as indirect selection via indicator traits such as feed intake, milk spectral data, and rumen microbial communities. Many of these traits are expensive or difficult to record, or both, but with genomic selection, inclusion of methane emission as a breeding goal trait is feasible, even with a limited number of registrations. At present, methane emission is not included among breeding goals for dairy cattle worldwide. There is no incentive to include enteric methane in breeding goals, although global warming and the release of greenhouse gases is a much-debated political topic. However, if selection for reduced methane emission became a reality, there would be limited consensus as to which phenotype to select for: methane in liters per day or grams per day, methane in liters per kilogram of energy-corrected milk or dry matter intake, or a residual methane phenotype, where methane production is corrected for milk production and the weight of the cow. We have reviewed the advantages and disadvantages of these traits, and discuss the methods for selection and consequences for these phenotypes.
Methaanemissie uit mest : schatters voor biochemisch methaan potentieel (BMP) en methaanconversiefactor (MCF)
Groenestein, C.M. ; Mosquera, J. ; Melse, R.W. - \ 2016
Wageningen : Wageningen Livestock Research (Livestock Research rapport 961) - 28
mest - methaan - emissie - broeikasgassen - dierhouderij - manures - methane - emission - greenhouse gases - animal husbandry
This report presents the results of a desk study performed to determine and justify the use of new BMP and MCF values for cattle, pig and poultry manure under Dutch conditions.
Mestgassen uit melkveemest : jaarrond metingen van H2S-concentraties
Timmerman, M. - \ 2016
Wageningen : Wageningen Livestock Research (Livestock Research rapport 1002) - 26
dierlijke meststoffen - broeikasgassen - emissie - melkveehouderij - animal manures - greenhouse gases - emission - dairy farming
Methodologies identification and certification of Low ILUC risk biofuels : final report
Peters, Daan ; Spöttle, ; Hähl, Thomas ; Kühner, Ann-Kathrin ; Cuijpers, Maarten ; Stomph, Tjeerd Jan ; Werf, Wopke van der; Grass, Martin - \ 2016
Utrecht : ECOFYS Netherlands - 58
biofuels - greenhouse gases - land use - biomass - biomass production - biobased economy - indirect land use change - biobrandstoffen - broeikasgassen - landgebruik - biomassa - biomassa productie - biobased economy - indirecte veranderingen van landgebruik
Biofuels can be an important instrument to decarbonise the transport sector. However, the greenhouse gas performance of biofuels can be negatively impacted by Indirect land use change (ILUC) effects. In this report, Ecofys proposes two methodologies to identify and demonstrate low ILUC risk biofuel feedstock production through the application of yield increase (see Chapter 3) or unused land (see ILUC mitigation methodology for unused land).
Methodology for estimating emissions from agriculture in the Netherlands. : Calculations of CH4, NH3, N2O, NOx, PM10, PM2.5 and CO2 with the National Emission Model for Agriculture (NEMA)
Vonk, J. ; Bannink, A. ; Bruggen, C. van; Groenestein, C.M. ; Huijsmans, J.F.M. ; Kolk, J.W.H. van der; Luesink, H.H. ; Oude Voshaar, S.V. ; Sluis, S.M. ; Velthof, G.L. - \ 2016
Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 53) - 164
air pollutants, greenhouse gases, livestock, crops, animal housing, manure storage, manure application, inorganic fertilizer, enteric fermentation, manure management, agricultural soils, liming, NIR, CRF, IIR, NFR - landbouw - gewassen - landbouwgronden - vee - huisvesting, dieren - dierlijke meststoffen - rundveemest - mestverwerking - begrazing - broeikasgassen - luchtverontreinigende stoffen - emissie - ammoniakemissie - kooldioxide - methaan - anorganische meststoffen - fermentatie - bekalking - nederland - compost - rioolslib - teelt - oogstresten - rijp worden - agriculture - crops - agricultural soils - livestock - animal housing - animal manures - cattle manure - manure treatment - grazing - greenhouse gases - air pollutants - emission - ammonia emission - carbon dioxide - methane - inorganic fertilizers - fermentation - liming - netherlands - composts - sewage sludge - cultivation - crop residues - ripening
The National Emission Model for Agriculture (NEMA) is used to calculate emissions to air from agricultural activities in the Netherlands on a national scale. Emissions of ammonia (NH3) and other N-compounds (NOx and N2O) from animal housing, manure storage, manure application and grazing are assessed using a Total Ammoniacal Nitrogen (TAN) flow model. Furthermore, emissions from application of inorganic N-fertilizer, compost and sewage sludge, cultivation of organic soils, crop residues, and ripening of crops are calculated. NEMA is also used to estimate emissions of methane (CH4) from enteric fermentation and manure management, particulate matter (PM) from manure management and agricultural soils, and carbon dioxide
(CO2) from liming. Emissions are calculated in accordance with international guidance criteria and reported in an annual Informative Inventory Report (IIR; for air pollutants) and National Inventory Report (NIR; for greenhouse gases). This methodology report describes the outline and backgrounds of the emission
calculations with NEMA
Feed sources for livestock : recycling towards a green planet
Zanten, H.H.E. van - \ 2016
Wageningen University. Promotor(en): Imke de Boer, co-promotor(en): Paul Bikker; Bastiaan Meerburg. - Wageningen : Wageningen University - ISBN 9789462578050 - 251
cum laude - livestock - livestock feeding - feeds - resources - food wastes - leftovers - recycling - greenhouse gases - environmental impact - innovations - sustainable animal husbandry - animal production - vee - veevoeding - voer - hulpbronnen - voedselafval - etensresten - recycling - broeikasgassen - milieueffect - innovaties - duurzame veehouderij - dierlijke productie
Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Current levels of production of especially animal-source food (ASF), pose severe pressure on the environment via their emissions to air, water, and soil; and their use of scarce resources, such as land, water, and fossil energy. The livestock sector, for example, is responsible for about 15% of the global anthropogenic emissions of greenhouse gases and uses about 70% of global agricultural land.
Many proposed mitigation strategies to feed the world sustainably, therefore, focus primarily on reducing the environmental impact of the livestock sector, so-called production-side strategies. Other strategies focus on changing consumption patterns by reducing consumption of ASF, or on shifting from ASF with a higher environmental impact (e.g. beef) to ASF with a lower environmental impact (e.g. pork or chicken), so called consumption-side strategies.
Most of the environmental impact of production of ASF is related to production of feed. One production-side strategy to reduce the environmental impact is the use of products that humans cannot or do not want to eat, such as co-products, food-waste, and biomass from marginal lands for livestock feed (referred to as ‘leftover streams’ in this thesis). This strategy is effective, because feeding leftover streams to livestock transforms an inedible food stream into high-quality food products, such as meat, milk, and eggs.
Two production-side strategies that use leftover streams as livestock feed were explored in this thesis: replacing soybean meal (SBM) in diets of growing pigs with either rapeseed meal (RSM) or with waste-fed larvae meal. Replacing SBM with RSM in growing-pig diets was assessed because RSM became increasingly available following an increase in bio-energy production in the EU. In this strategy, therefore, the RSM content in pig diets increased at the expense of SBM. SBM is an ingredient associated with a high environmental impact. It was expected, therefore, that replacing SBM with RSM in pig diets would lead to a decrease in the environmental impact of pork production. Replacing SBM with waste-fed larvae meal was assessed because recent developments show the environmental benefits of rearing insects as livestock feed. Insects have a low feed conversion ratio (kg feed/kg product) and can be consumed completely, without residual materials, such as bones or feathers. The nutritional value of insects is high, especially as a protein source for livestock. Insect-based feed products, therefore, can replace conventional feed ingredients, such as SBM. Altogether this strategy suggests that waste-fed larvae meal might become an important alternative feed source in the future.
To gain insight into the status quo of the environmental impact of both mitigation strategies, replacing SBM with RSM or with waste-fed insects, we first used the attributional life cycle assessment (ALCA) method. Based on the ALCA method, results showed that each mitigation strategy was promising. Replacing SBM with RSM in growing pig diets hardly changed either global warming potential (GWP) or energy use (EU), but decreased land use (LU) up to 16% per kg body weight gain. As expected, feed production had the largest environmental impact, responsible for about 50% of the GWP, 60% of the EU, and 77% of the total LU. Feed production in combination with feed intake, were the most sensitive parameters; a small change in both these two parameters changed the results. Replacing SBM with waste-fed larvae meal in growing-pig diets showed that EU hardly changed, but GWP (29%) and LU (54%) decreased per kg body weight gain. Based on ALCA results, each mitigation strategy, therefore, seems to offer potential to reduce the environmental impact of pork production. An ALCA, however, has two disadvantages: it does not account for product-packages and it does not consider feed-food competition.
The first disadvantage of ALCA was that the complexity of dealing with product-packages is not fully considered. ‘Product-package’ refers to a multiple-output situation. During the processing of sugar beet, for example, beet-pulp and molasses are produced in addition to sugar. Sugar, beet-pulp, and molasses together form a ‘package of products’ because they cannot be produced independently from each other. An ALCA does not account for the fact that the production volume of the co-product(s) depends on the demand for the determining product (e.g. sugar), which results in the limited availability of co-products. Increasing the use of co-products in animal feed, consequently, results in reducing use of a co-product in another sector, requiring them to be replaced with a different product. The environmental impact of increasing the use of a co-product or food-waste, therefore, depends on the net environmental impact. The net environmental impact refers to the environmental benefits of using the product in its new application minus the environmental cost of replacing the product in its old application.
A consequential theoretical framework was developed to account for product-packages. The results, based on the consequential framework, contradicted standard ALCA results. The consequential LCA (CLCA) method we used for replacing SBM with RSM showed an increased GWP (up to 15%), EU (up to 12%), and LU (up to 10%) per kg body weight gain. Moreover, this CLCA method showed that replacing SBM with waste-fed larvae meal increased GWP (60%) and EU (90%), but decreased LU (73%) per kg body weight gain.
Accounting for product-packages increased the net environmental impact of each strategy, replacing SBM with RSM or with waste-fed larvae meal. The difference in results between ALCA and CLCA was especially large in the strategy with waste-fed larvae meal. The difference was caused mainly by the use of food-waste. Food-waste fed to larvae was used initially to produce bio-energy via anaerobic digestion. In CLCA, the environmental impact related to replacing the bio-energy function of food-waste with fossil-energy was included. The net environmental impact became negative, because environmental benefits of replacing SBM with waste-fed larvae meal were less than environmental costs related to the marginal energy source, i.e. fossil energy, replacing the bio-energy. Results of the indirect environmental impact, however, are situation specific: if the marginal energy source were wind or solar energy, the net environmental impact of using waste-fed larvae meal might be positive. Waste-fed larvae meal, therefore, appears to be an interesting mitigation strategy only when energy from wind and solar energy are used more dominantly than energy from fossil sources.
If results were based solely on ALCA, then these potentially negative impacts would have been overlooked. Consideration of the environmental consequences of product-packaging, therefore, is essential to determine total environmental costs. If policy makers or the feed industry want to assess the net environmental impact of a potential mitigation strategy, then we recommend to perform a CLCA instead of an ALCA. The framework developed in this thesis can be used to perform such an assessment.
The second disadvantage of an LCA was that it does not take into account feed-food competition, e.g. competition for land between humans and animals. Most LCA studies focus on the total amount of land required to produce one kg ASF. LCA studies do not account for competition for land between humans and animals, or so-called feed-food competition. In other words, they do not include, differences in the consumption of human-edible products by various livestock species or differences in the suitability of land used for feed production as land to cultivate food-crops directly. Given the global constraints on land, it is more efficient to grow food directly for human consumption rather than for livestock. To address the contribution of livestock to a future sustainable food supply, a measure for land use efficiency was developed, called the land use ratio (LUR). The LUR accounts for plant productivity, efficiency of converting human-inedible feed into ASF, and suitability of land for crop cultivation. The LUR also has a life-cycle perspective.
Results of the LUR illustrated that dairy cows on sandy soil, laying hens, and pig production systems in the Netherlands have a LUR >1.0. In terms of protein produced per m2, therefore, it is more efficient to use these soils for livestock production to produce crops for direct human consumption than to produce feed for livestock. Only dairy cows on peat soil produce human digestible protein (HDP) more efficiently than crops do, because peat is not suitable for crop production. The LUR allows identification of livestock production systems that are able to produce HDP more efficiently than crops do. Livestock systems with a LUR<1.0, such as dairy on peat, have an important role to play in future sustainable nutrition supply.
Results of the LUR showed that livestock production systems using mainly co-products, food-waste, and biomass from marginal land, can produce human digestible protein more efficiently than crop production systems do. The availability of those leftover streams, however, is limited and, therefore, the amount of ASF produced based only on leftover streams is also limited. Because LUR is a ratio, LUR results do not give an indication of how much ASF can be produced based on livestock systems that feed mainly on leftover streams.
The third, and last, mitigation strategy, therefore, focused on the amount of ASF that can be consumed by humans, when livestock are fed only on leftover steams, also referred to as “default livestock”. The calculation of the amount of ASF was based on the assumption that a vegan diet was consumed in principle. The resulting co-products and food-waste were fed to pigs and, biomass from grazing land was fed to ruminants. Results showed that in total 21 g animal source protein per person per day could be produced by feeding livestock entirely on leftovers.
Considering feed-food crops and feeding food-waste made an important contribution to the 21 g of protein that could be produced from default livestock. Considering feed-food crops implies that choices have to be made between different crops, based on their contribution to feed and food production. Oil production from soy cultivation, for example, resulted in the co-product SBM. Results showed that considering feed-food crops can affect the final protein production from pork. The practice of feeding food-waste to livestock is currently prohibited due to problems of food safety but the practice shows potential in extensively reducing the environmental impact of livestock production. Considering feed-food crops and feeding food-waste are examples of mitigation strategies that currently can be implemented to reduce further the environmental impact of the livestock sector.
On average, it is recommended to consume about 57 g of protein from ASF or plant-origin per person per day. Only ASF from default livestock does not fulfil the current global protein consumption of 32 g per person per day, but about one third of the protein each person needs can be produced without any competition for land between feed and food production. To feed the world more sustainably, by requiring livestock production systems with a LUR <1.0, however, a paradigm shift is needed. Global average consumption of ASF should decrease to about 21 g of protein per person per day. Innovations are needed, moreover, to overcome problems of food safety and technical concerns related to collecting the leftover streams. This applies, in particular to food-waste, which is currently unused in livestock production but which presents a valuable strategy in mitigating environmental impacts caused by livestock production. Livestock systems should change their focus, furthermore, from increasing productivity per animal towards increasing protein production for humans per ha. By using leftover streams optimally, the livestock sector is able to produce a crucial amount of protein, while still avoiding competition for land between feed and food crops. Livestock, therefore, can make an important contribution to the future nutrition supply.
An uncertain climate : the value of uncertainty and sensitivity analysis in environmental impact assessment of food
Groen, E.A. - \ 2016
Wageningen University. Promotor(en): Imke de Boer, co-promotor(en): Eddy Bokkers; R. Heijungs. - Wageningen : Wageningen University - ISBN 9789462577558 - 239
environment - environmental impact - climatic change - uncertainty analysis - screening - sensitivity analysis - modeling - greenhouse gases - farms - dairy farms - food production - correlation analysis - milieu - milieueffect - klimaatverandering - onzekerheidsanalyse - screenen - gevoeligheidsanalyse - modelleren - broeikasgassen - landbouwbedrijven - melkveebedrijven - voedselproductie - correlatieanalyse
Production of food contributes to climate change and other forms of environmental impact. Input data used in environmental impact assessment models, such as life cycle assessment (LCA) and nutrient balance (NB) analysis, may vary due to seasonal changes, geographical conditions or socio-economic factors (i.e. natural variability). Moreover, input data may be uncertain, due to measurement errors and observational errors that exist around modelling of emissions and technical parameters (i.e. epistemic uncertainty). Although agricultural activities required for food production are prone to natural variability and epistemic uncertainty, very few case studies in LCA and NB analysis made a thorough examination of the effects of variability and uncertainty. This thesis aimed to enhance understanding the effects of variability and uncertainty on the results, by means of uncertainty and sensitivity analysis. Uncertainty analysis refers to the estimation of the uncertainty attribute of a model output using the uncertainty attributes of the model in- puts. There are three types of sensitivity analyses: (I) a local sensitivity analysis addresses what happens to the output when input parameters are changed, i.e. the intrinsic model behaviour of a parameter; (II) a screening analysis addresses what happens to the output based on the un- certainty range of the different input parameters; and (III) a global sensitivity analysis addresses how much the uncertainty around each input parameter contributes to the output variance. Both the screening analysis and the global sensitivity analysis combine the intrinsic model behaviour with the information of uncertainty around input parameters. Applying uncertainty analysis and sensitivity analysis can help to reduce the efforts for data collection, support the development of mitigation strategies and improve overall reliability, leading to more informed decision making in environmental impact assessment models. Including uncertainty in environmental impact assessment models showed that: (1) the type of uncertainty analysis or sensitivity analysis applied depends on the question to be addressed and the available information; (2) in some cases it is no longer possible to benchmark environmental performance if epistemic uncertainty is included; (3) including correlations between input parameters during uncertainty propagation will either increase or decrease output variance, which can be predicted beforehand; (4) under specific characteristics of the input parameters, ignoring correlation has a minimal effect on the model outcome. Systematically combining a local and global sensitivity analysis in environmental impact assessment models: (1) resulted in more parameters than found previously in similar studies (for the case studies discussed in this thesis); (2) allowed finding mitigation options, either based on innovations (derived from the local sensitivity analysis) or on management strategies (derived from the global sensitivity analysis); (3) showed for which parameters reliability should be improved by increasing data quality; (4) showed that reducing the (epistemic) uncertainty of the most important parameters can affect the comparison of the environmental performance.
Measurement methods to assess methane production of individual dairy cows in a barn
Wu, L. - \ 2016
Wageningen University. Promotor(en): Peter Groot Koerkamp, co-promotor(en): Nico Ogink. - Wageningen : Wageningen University - ISBN 9789462577312 - 190
dairy cows - cows - methane production - barns - measurement techniques - modeling - breath - uncertainty analysis - greenhouse gases - cubicles - melkkoeien - koeien - methaanproductie - landbouwschuren - meettechnieken - modelleren - adem - onzekerheidsanalyse - broeikasgassen - ligboxen
Mitigation of methane production from dairy cows is critical to reduce the dairy industry’s contribution to the production of greenhouse gases. None of current used methane measurement methods are flawless and application of the methods is limited to assess the effects of methane mitigation methods under practical conditions. The main objective of this thesis is to design, test, and validate methods to determine or rank the methane production of individual dairy cows at farm house level.
As a start, I evaluated merits and drawbacks of existing methane measurement methods and discussed against 14 requirements of methane measurement methods to assess methane mitigation strategies. This review study revealed that none of existing methods meet all requirements, and pointed out that sampling of breath air during the lying period of cows in cubicles could be a practical direction to measure methane production of individual cows under farm conditions. Therefore, we first assessed methane concentration levels and variations in time, and around cubicles, explored effects of barn and management factors on them, and assessed the effect of the variation of the background methane concentrations on assessing methane production of individual dairy cows in cubicles. Then, we designed and constructed an artificial reference cow (ARC) that mimics the methane production of real cows with known pre-set methane production rates and dynamics of eructations. With the acquired background information and the developed ARC, we assessed the uncertainty of a breath methane concentration (BMC) method in a feeder and developed a cubicle hood sampler (CHS) that measures methane fluxes from lying cows in cubicles. The observed uncertainty related to random errors of the BMC method can be overcome by sufficient numbers of repetitions. However identified uncertainty with a systematic nature, related to inconsistent relation between concentration and production rate, cannot be compensated by repeated measurements and requires further investigation into the widely used BMC method before it can be used with confidence. Compared to the BMC method, the developed CHS is not subject to such systematic effects and allows prolonged measurement periods. Performance test under field conditions showed that the designed CHS accurately measured methane fluxes provided by the ARC.
Overall, in this thesis I assessed the measurement error of current three methane measurement principles (flux, breath concentration & tracer gas), provided information to limit the measurement variation, and assessed the availability to determine or rank the methane production of individual dairy cows at farm house level. The newly developed ARC can be used as a known reference source to calibrate and develop practical methane measurement methods, and the CHS is sufficiently accurate to measure methane production of individual cows at farm house level.
Meer voedsel, minder broeikasgas : landbouw en voedselproductie na Parijs
Verhagen, Jan ; Vellinga, Pier - \ 2016
climatic change - climate adaptation - agriculture and environment - greenhouse gases - agricultural production - groundwater depletion - heat - salinization - emission reduction - food production - food security
De klimaatconferentie in Parijs markeert het retour van de fossiele brandstoffen, vindt scheidend hoogleraar Pier Vellinga. Hij hoopt dat nu ook de uitstoot van broeikasgassen uit de landbouw omlaag gaat. Wageningse wetenschappers zijn daar al mee bezig, maar ook proberen ze de gevolgen van klimaatverandering het hoofd te bieden. Hoe valt er voldoende te produceren bij verdroging, hitte en verzilting?
Inpassen van maatregelen ter reductie van gasvormige emissies in de bedrijfsvoering van melkveebedrijven : Koeien & Kansen resultaten 2010-2013
Goselink, R.M.A. ; Sebek, L.B. ; Hilhorst, G.J. ; Evers, A.G. ; Haan, M.H.A. de - \ 2016
Wageningen : Wageningen UR Livestock Research (Rapport / Koeien & Kansen nr. 76) - 33
broeikasgassen - emissie - maatregelen - ammoniakemissie - emissiereductie - luchtkwaliteit - agrarische bedrijfsvoering - melkveebedrijven - duurzame veehouderij - melkveehouderij - greenhouse gases - emission - measures - ammonia emission - emission reduction - air quality - farm management - dairy farms - sustainable animal husbandry - dairy farming
In 2010 the dairy farmers of Cows & Opportunities have started working on a new project goal: gaseous emissions. To continue their role as pilot farm within the future developments in the dairy sector new goals have been added to their original goals on optimizing the nitrogen en phosphorus cycle: reducing greenhouse gas emissions and ammonia. The ultimate goal for 2013 was a 30% reduction of the average greenhouse gas emission of nitrous oxide (N2O) and methane (CH4) together, relative to the average Dutch dairy farm in 1990. In addition to the reduction of greenhouse gases, a second aim was to further reduce ammonia (NH3) emissions with 10% relative to the individual farm level in 2009. In 2009 the autonomously achieved reduction on greenhouse gas emissions turned out to be 29%, and this was further improved to 31% in 2013, reaching the project goal. This improvement was reached by both a reduction of N2O and CH4. The reduction of the N2O emission reached already 56% in 2009, but unexpectedly grew to 62% in 2013, partly by an increase in production intensity (kg FPCM per ha). The reduction of CH4 emission was less substantial, starting at 12% in 2009 and fluctuating around 13% in 2010-2013. The second aim was to further reduce NH3 emissions to an average of 3.2 kg NH3 per 1000 kg FPCM (10% reduction relative to the individual farm level in 2009). This was reached in 2013, showing that this goal was realistic even while working on other project goals like CH4 reduction in parallel. The decline in the NH3 emission is mainly achieved at the project farms situated on sandy soils and peat, while the emission of project farms on clay soils stayed relatively constant. Farm-specific circumstances such as the weather and roughage quality will influence the effect of measurements, thereby causing fluctuations in the emissions over the years. Working on the reduction of gaseous emissions is however possible on the average Dutch dairy farm and may lead to a reduction of 25% relative to 1990, looking at the autonomous reduction already reach in Cows & Opportunities in 2009. Further reduction of greenhouse gas emissions will cost more effort. If 50% of the Dutch dairy farmers also reaches a decrease in NH3 emission in 2020 comparable to the farmers in Cows & Opportunities have reached in 2013, the emission of the dairy sector wil be 3.6 kg NH3 per 1000 kg FPCM. Dairy farmers will however need high management skills, as they have to run a complex farming system and work simultaneously on a variety of financial, social and environmental objectives all-year.