Records 1 - 20 / 1379
What makes a volatile organic compound a reliable indicator of insect herbivory?
Douma, Jacob C. ; Ganzeveld, Laurens N. ; Unsicker, Sybille B. ; Boeckler, Andreas ; Dicke, Marcel - \ 2019
Plant, Cell & Environment 42 (2019)12. - ISSN 0140-7791 - p. 3308 - 3325.
biogenic volatile organic compound (BVOC) - emission - herbivore induced plant volatile (HIPV) - hydroxyl radical - nitrate radical - oxidation - ozone - Populus nigra
Plants that are subject to insect herbivory emit a blend of so-called herbivore-induced plant volatiles (HIPVs), of which only a few serve as cues for the carnivorous enemies to locate their host. We lack understanding which HIPVs are reliable indicators of insect herbivory. Here, we take a modelling approach to elucidate which physicochemical and physiological properties contribute to the information value of a HIPV. A leaf-level HIPV synthesis and emission model is developed and parameterized to poplar. Next, HIPV concentrations within the canopy are inferred as a function of dispersion, transport and chemical degradation of the compounds. We show that the ability of HIPVs to reveal herbivory varies from almost perfect to no better than chance and interacts with canopy conditions. Model predictions matched well with leaf-emission measurements and field and laboratory assays. The chemical class a compound belongs to predicted the signalling ability of a compound only to a minor extent, whereas compound characteristics such as its reaction rate with atmospheric oxidants, biosynthesis rate upon herbivory and volatility were much more important predictors. This study shows the power of merging fields of plant–insect interactions and atmospheric chemistry research to increase our understanding of the ecological significance of HIPVs.
Balance of Emission and Dynamical Controls on Ozone During the Korea-United States Air Quality Campaign From Multiconstituent Satellite Data Assimilation
Miyazaki, K. ; Sekiya, T. ; Fu, D. ; Bowman, K.W. ; Kulawik, S.S. ; Sudo, K. ; Walker, T. ; Kanaya, Y. ; Takigawa, M. ; Ogochi, K. ; Eskes, H. ; Boersma, K.F. ; Thompson, A.M. ; Gaubert, B. ; Barre, J. ; Emmons, L.K. - \ 2019
Journal of Geophysical Research: Atmospheres 124 (2019)1. - ISSN 2169-897X - p. 387 - 413.
air quality - Asia - data assimilation - emission - ozone - satellite
Global multiconstituent concentration and emission fields obtained from the assimilation of the satellite retrievals of ozone, CO, NO2, HNO3, and SO2 from the Ozone Monitoring Instrument (OMI), Global Ozone Monitoring Experiment 2, Measurements of Pollution in the Troposphere, Microwave Limb Sounder, and Atmospheric Infrared Sounder (AIRS)/OMI are used to understand the processes controlling air pollution during the Korea-United States Air Quality (KORUS-AQ) campaign. Estimated emissions in South Korea were 0.42 Tg N for NOx and 1.1 Tg CO for CO, which were 40% and 83% higher, respectively, than the a priori bottom-up inventories, and increased mean ozone concentration by up to 7.5 ± 1.6 ppbv. The observed boundary layer ozone exceeded 90 ppbv over Seoul under stagnant phases, whereas it was approximately 60 ppbv during dynamical conditions given equivalent emissions. Chemical reanalysis showed that mean ozone concentration was persistently higher over Seoul (75.10 ± 7.6 ppbv) than the broader KORUS-AQ domain (70.5 ± 9.2 ppbv) at 700 hPa. Large bias reductions (>75%) in the free tropospheric OH show that multiple-species assimilation is critical for balanced tropospheric chemistry analysis and emissions. The assimilation performance was dependent on the particular phase. While the evaluation of data assimilation fields shows an improved agreement with aircraft measurements in ozone (to less than 5 ppbv biases), CO, NO2, SO2, PAN, and OH profiles, lower tropospheric ozone analysis error was largest at stagnant conditions, whereas the model errors were mostly removed by data assimilation under dynamic weather conditions. Assimilation of new AIRS/OMI ozone profiles allowed for additional error reductions, especially under dynamic weather conditions. Our results show the important balance of dynamics and emissions both on pollution and the chemical assimilation system performance.
Dooren, H.J.C. van; Mosquera Losada, J. ; Bokma, S. ; Groenestein, C.M. - \ 2018
Wageningen : Wageningen Livestock Research - 5 p.
animal welfare - animal production - dairy cattle - animal housing - environment - emission - teaching materials - intermediate vocational training
Door onderzoekers van Wageningen Livestock Research is het belang aangegeven om de emissie van ammoniak terug te dringen en zijn oplossingsrichtingen aangegeven. De volgende thema’s worden toegelicht: 1.Ammoniakproblematiek 2.Meten ammoniakemissie in stal 3.Oplossingsrichtingen verminderen emissie
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
Predicting methane emission of dairy cows using milk composition
Gastelen, Sanne van - \ 2017
Wageningen University. Promotor(en): W.H. Hendriks, co-promotor(en): J. Dijkstra; K.A. Hettinga. - Wageningen : Wageningen University - ISBN 9789463437097 - 266
dairy cows - dairy cattle - methane production - emission - milk composition - fatty acids - cattle feeding - fermentation - nutrition physiology - animal nutrition - pollution - melkkoeien - melkvee - methaanproductie - emissie - melksamenstelling - vetzuren - rundveevoeding - fermentatie - voedingsfysiologie - diervoeding - verontreiniging
Enteric methane (CH4) is produced as a result of microbial fermentation of feed components in the gastrointestinal tract of ruminant livestock. Methane has no nutritional value for the animal and is predominately released into the environment through eructation and breath. Therefore, CH4 not only represents a greenhouse gas contributing to global warming, but also an energy loss, making enteric CH4 production one of the main targets of greenhouse gas mitigation practices for the dairy industry. Obviously, reduction of CH4 emission could be achieved by simply reducing livestock numbers. However, the global demand for dairy products has been growing rapidly and is expected to further grow in the future. Therefore, it is critical to minimize environmental impact to produce high-quality dairy products. The overall aim of this PhD research was, therefore, to develop a proxy for CH4 emission that can be measured in milk of dairy cows.
There are currently a number of potentially effective dietary CH4 mitigation practices available for the livestock sector. The results of Chapter 3 show that replacing fiber-rich grass silage with starch-rich corn silage in a common forage-based diet for dairy cattle offers an effective strategy to decrease enteric CH4 production without negatively affecting dairy cow performance, although a critical level of starch in the diet seems to be needed. Little is known whether host genetics may influence the CH4 emission response to changes in diet. Therefore, the interaction between host DGAT1 K232A polymorphism with dietary linseed oil supplementation was evaluated in Chapter 7. The results of Chapter 7 indicate that DGAT1 K232A polymorphism is associated with changes in milk composition, milk N efficiency, and diet metabolizability, but does not affect digestibility and enteric CH4 emission, whereas linseed oil reduces CH4 emission independent of the DGAT1 K232A polymorphism.
Accurate and repeatable measurements of CH4 emission from individual dairy cows are required to assess the efficacy of possible mitigation strategies. There are several techniques to estimate or measure enteric CH4 production of dairy cows, including climate respiration chambers, but none of these techniques are suitable for large scale precise and accurate measurements. Therefore, the potential of various metabolites in milk, including milk fatty acids (MFA), as a proxy (i.e., indicators or animal traits that are correlated with enteric CH4 production) for CH4 emission of dairy cows gained interest. Until recently, gas chromatography was the principal method used to determine the MFA profile, but this technique is unsuitable for routine analysis. This has led to the application of Fourier-transform infrared spectroscopy (FTIR) for determination of the MFA profile. Chapter 2 provides an overview of the recent research that relates MFA with CH4 emission, and discusses the opportunities and limitations of using FTIR to estimate, indirectly via MFA or directly, CH4 emission of dairy cattle. The recent literature on the relationship between MFA and CH4 emission gives inconsistent results. Where some studies found a clear and strong relation, other studies consider MFA to be unreliable predictors for CH4 emitted by dairy cows. Even the studies that do find a clear relation between MFA and CH4 emissions do not describe similar prediction models using the same MFA. These discrepancies can be the result of many factors, including dietary composition and lactation stage. Additionally, literature showed that the major advantages of using FTIR to predict CH4 emission include its simplicity and potential practical application on a large scale. Disadvantages include the inability to predict important MFA for the prediction of CH4 emission, and the moderate power of FTIR to directly predict CH4 emission. The latter was also demonstrated in Chapter 9, in which the CH4 prediction potential of MFA was compared with that of FTIR using data from 9 experiments (n = 218 individual cow observations) covering a broad range of roughage-based diets. The results indicate that MFA have a greater potential than FTIR spectra to estimate CH4 emissions, and that both techniques have potential to predict CH4 emission of dairy cows, but also limited current applicability in practice. Much focus has been placed on the relationship between MFA and CH4 emission, but milk also contains other metabolites, such as volatile and non-volatile metabolites. Currently, milk volatile metabolites have been used for tracing animal feeding systems and milk non-volatile metabolites were shown to be related to the health status of cows. In Chapter 4, the relationship between CH4 emission and both volatile and non-volatile metabolites was investigated, using data and milk samples obtained in the study described in Chapter 3. In general, the non-volatile metabolites were more closely related to CH4 emissions than the volatile metabolites. More specifically, the results indicate that CH4 intensity (g/kg fat- and protein-corrected milk; FPCM) may be related to lactose synthesis and energy metabolism in the mammary gland, as reflected by the milk non-volatile metabolites uridine diphosphate-hexose B and citrate. Methane yield (g/kg dry matter intake) on the other hand, may be related to glucogenic nutrient supply, as reflected by the milk non-volatile acetone. Based on the metabolic interpretations of these relationships, it was hypothesized that the addition of both volatile and non-volatile metabolites in a prediction model with only MFA would enhance its predictive power and, thus, leads to a better proxy in milk for enteric CH4 production of dairy cows. This was investigated in Chapter 5, again using data and milk samples described in Chapter 3. The results indicate that MFA alone have moderate to good potential to estimate CH4 emission. Furthermore, including volatile metabolites (CH4 intensity only) and non-volatile metabolites increases the CH4 emission prediction potential.
The work presented in Chapters 3, 4 and 5, was based upon a small range of diets (i.e., four roughage-based diets in which grass silage was replaced partly or fully by corn silage) of one experiment. Therefore, in Chapter 6, the relationship between CH4 emission and the milk metabolome in dairy cattle was further quantified. Data (n = 123 individual cow observations) were used encompassing a large of roughage-based diets, with different qualities and proportions of grass, grass silage and corn silage. The results show that changes in individual milk metabolite concentrations can be related to the ruminal CH4 production pathways. These relationships are most likely the result from changes in dietary composition that affect not only enteric CH4 production, but also the profile of volatile and non-volatile metabolites in milk. Overall, the results indicate that both volatile and non-volatile metabolites in milk might provide useful information and increase our understanding of CH4 emission of dairy cows. However, the development of CH4 prediction models revealed that both volatile and non-volatile metabolites in milk hold little potential to predict CH4 emissions despite the significant relationships found between individual non-volatile metabolites and CH4 emissions. Additionally, combining MFA with milk volatile metabolites and non-volatile metabolites does not improve the CH4 prediction potential relative to MFA alone. Hence, it is concluded that it is not worthwhile to determine the volatile and non-volatile metabolites in milk in order to estimate CH4 emission of dairy cows.
Overall, in comparison with FTIR, volatile and non-volatile metabolites, the MFA are the most accurate and precise proxy in milk for CH4 emission of dairy cows. However, most of MFA-based models to predict CH4 emission tend to be accurate only for the production system and the environmental conditions under which they were developed. In Chapter 8 it was demonstrated that previously developed MFA-based prediction equations did not predict CH4 emission satisfactory of dairy cows with different DGAT1 genotypes or fed diets with or without linseed oil. Therefore, the greatest shortcoming today of MFA-based CH4 prediction models is their lack of robustness. Additionally, MFA have restricted practical application, meaning that most MFA retained in the current CH4 prediction models cannot be determined routinely because of the use of gas chromatography. The MFA that can be determined with the use of infrared spectroscopy are however no promising predictors for CH4 emission. Furthermore, MFA have only a moderate CH4 prediction potential. This together suggests that it might not be the best option to focus in the future on MFA alone as a proxy for CH4 emission of dairy cows.
The FTIR technique has a low to moderate CH4 prediction potential. However, FTIR has a great potential for practical high throughput application, facilitating repeated measurements of the same cow potentially reducing random noise. Results of this thesis also demonstrated that FTIR spectra do not have the potential to detect differences in CH4 emission between diets which are, in terms of forage level and quality, commonly fed in practice. Moreover, the robustness of FTIR spectra is currently unknown. Hence, it remains to be investigated whether FTIR spectra can predict CH4 emissions from dairy cows housed under different conditions from those under which the FTIR-based prediction equations were developed. It is therefore concluded that the accuracy and precision to predict CH4 emission using FTIR needs to increase, and the capacity of FTIR to evaluate the differences in CH4 emission between dairy cows and different types of diets needs to improve, in order to actually be a valuable proxy for CH4 emission of dairy cows.
The SEEA EEA carbon account for the Netherlands
Lof, Marjolein ; Schenau, Sjoerd ; Jong, Rixt de; Remme, Roy ; Graveland, Cor ; Hein, Lars - \ 2017
The Hague : Statistics Netherlands - 64
carbon dioxide - netherlands - carbon - economics - environment - biofuels - bioenergy - biogas - emission - kooldioxide - nederland - koolstof - economie - milieu - biobrandstoffen - bio-energie - biogas - emissie
The carbon account provides a comprehensive overview of all relevant carbon stocks and flows. The carbon account for the Netherlands was developed within the scope of the ‘System of Environmental Economic Accounts – Experimen tal Ecosystem Accounting’ (SEEA EEA) project for the Netherlands (Natuurlijk Kapitaalrekeningen Nederland: NKR_NL), which is currently c arried out jointly by Statistics Netherlands and Wageningen University. Funding and support was provided by the Ministries of Economic Affairs and Infrastructure and the Environment. Within the NKR_NL project, a number of accounts are currently under devel opment. The carbon account is described in detail in this report.
Emissies naar lucht uit de landbouw in 2014 : berekeningen met het model NEMA
Bruggen, C. van; Bannink, A. ; Groenestein, C.M. ; Huijsmans, J.F.M. ; Luesink, H.H. ; Oude Voshaar, S.V. ; Sluis, S.M. van der; Velthof, G.L. ; Vonk, J. - \ 2017
Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 90) - 96
ammoniak - landbouw - emissie - mest - distikstofmonoxide - dierhouderij - modellen - nederland - ammonia - agriculture - emission - manures - nitrous oxide - animal husbandry - models - netherlands
Landbouwkundige activiteiten zijn in Nederland een belangrijke bron van ammoniak (NH3), stikstofoxide (NO), lachgas (N2O),methaan (CH4) en fijnstof (PM10 en PM2,5). De emissies in 2014 zijn berekend met het National Emission Model for Agriculture(NEMA). Tegelijk zijn enkele cijfers in de reeks 1990-2013 aangepast op basis van nieuwe inzichten. De rekenmethodiek gaatbij de berekening van de ammoniakemissie uit dierlijke mest uit van de hoeveelheid totaal ammoniakaal stikstof (TAN) in demest. De ammoniakemissie uit dierlijke mest, kunstmest en overige bronnen in 2014 bedroeg 121 miljoen kg NH3, bijna4 miljoen kg meer dan in 2013. De stijging komt voornamelijk door uitbreiding van de melkveestapel en een hogerstikstofgehalte van het ruwvoer. De N2O-emissie nam toe van 19,1 miljoen kg in 2013 naar 19,4 miljoen kg in 2014. De NOemissienam toe van 16,9 naar 17,2 miljoen kg. De methaanemissie nam iets toe van 499 tot 503 miljoen kg. De emissie vanfijnstof nam licht toe van 6,3 miljoen kg PM10 tot 6,4 miljoen kg, door een toename van het aantal stuks pluimvee. De emissievan PM2,5 bedroeg in beide jaren 0,6 miljoen kg. Sinds 1990 is de ammoniakemissie uit dierlijke mest en kunstmest mettweederde gedaald, vooral door een lagere stikstofuitscheiding door landbouwhuisdieren en emissiearme mesttoediening.Emissies van lachgas en stikstofoxide daalden in dezelfde periode eveneens, maar minder sterk (ca. 40%) omdat doorondergronds toedienen van mest de emissies hoger zijn geworden en door de omschakeling van stalsystemen met dunne naarvaste mest bij pluimvee. Tussen 1990 en 2014 daalde de emissie van methaan met 16% door een afname in de dieraantallenen een hogere voeropname en productiviteit van melkvee---Agricultural activities are in the Netherlands a major source of ammonia (NH3), nitrogen oxide (NO), nitrous oxide (N2O),methane (CH4) and particulate matter (PM10 and PM2.5). The emissions in 2014 were calculated using the National EmissionModel for Agriculture (NEMA). At the same time some figures in the time series 1990-2013 were revised. The method calculatesthe ammonia emission from livestock manure on the basis of the total ammonia nitrogen (TAN) content in manure. Ammoniaemissions from livestock manure, fertilizers and other sources in 2014 were 121 million kg, which was almost 4 million kghigher than in 2013, mainly due to expansion of the dairy herd and a higher N-content of roughage. N2O emissions increasedfrom 19.1 million kg in 2013 to 19.4 million kg in 2014. NO emission increased slightly from 16.9 to 17.2 million kg. Methaneemissions increased from 499 to 503 million kg. Emissions of particulate matter increased slightly from 6.3 to 6.4 million kgPM10 as a result of higher poultry numbers. Emission of PM2.5 in both years was 0.6 million kg. Ammonia emissions fromlivestock manure in the Netherlands dropped by almost two thirds since 1990, mainly as a result of lower nitrogen excretionrates by livestock and low-emission manure application. Nitrous oxide and nitrogen oxide also fell over the same period, butless steeply (by about 40%), due to higher emissions from manure injection into the soil and to the shift from poultry housingsystems based on liquid manure to solid manure systems. Methane emissions fell by 16% between 1990 and 2014 caused by adrop in livestock numbers and increased feed uptake and productivity of dairy cattle
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
Rekenregels rundvee voor de Landbouwtelling : verantwoording van het gebruik van het Identificatie & Registratiesysteem
Os, J. van; Bartholomeus, M.G.T.M. ; Jeurissen, L.J.J. ; Reenen, C.G. van - \ 2017
Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-technical report 91) - 68
rundveehouderij - rundvee - landbouwtellingen - emissie - registratie - identificatie - bedrijfsstructuur in de landbouw - nederland - cattle husbandry - cattle - agricultural censuses - emission - registration - identification - farm structure - netherlands
Om te voldoen aan statistische verplichtingen voor veehouderij en bedrijfsstructuur en voor de registratievan emissies is informatie nodig over de rundveehouderij in Nederland. Daartoe vraagt de Rijksoverheid bijveehouders op hoeveel rundvee aanwezig is, uitgesplitst in verschillende diergroepen; dit is een onderdeelvan de jaarlijkse landbouwtelling. De Rijksoverheid streeft naar beperking van administratieve lastendruk bijondernemers. Wageningen Environmental Research heeft op verzoek van het ministerie van EconomischeZaken onderzocht in welke mate het mogelijk is om de benodigde gegevens af te leiden uit het bestaandeIdentificatie & Registratiesysteem (I&R) Rundveehouderij (een systeem voor identificatie en registratie vandieren voor dier- en volksgezondheid). Dat blijkt grotendeels goed haalbaar; voor de meeste bedrijvenkunnen alle diergroepen automatisch uit I&R bepaald worden. Voor sommige bedrijven is een aanvullendeverdeling van diergroepen over productiedoelen nodig. Deze nieuwe werkwijze leidt niet alleen tot lagereadministratieve lasten, maar ook tot een kwaliteitsverbetering van de rundveegegevens.---Information on cattle farming in the Netherlands is needed for the national statistics on beef and dairy farmsand farm structure. To obtain this information the national government asks farmers to submit informationon the number of cattle on their farms, divided into the various animal classes, as part of the annualagricultural census. The government also wants to minimise the administrative burden on farmers. At therequest of the Ministry of Economic Affairs, Wageningen Environmental Research has studied to what extentit would possible to derive the required information from the existing identification and registration system(I&R) for beef and dairy farms (a system for identifying and registering livestock for animal and humanhealth purposes). The results show that this is largely possible: for most farms all the animal classes can beautomatically derived from the I&R. For some farms it is necessary to make an additional division of animalclasses by product category. This new way of working will not only reduce the administrative burden, but itwill also lead to better quality data on beef and dairy cattle.
Assessing methane emission from dairy cows : modeling and experimental approaches on rumen microbial metabolism
Lingen, Henk J. - \ 2017
Wageningen University. Promotor(en): W.H. Hendriks, co-promotor(en): J. Dijkstra; A. Bannink; C.M. Plugge. - Wageningen : Wageningen University - ISBN 9789463431590 - 207
dairy cows - methane - emission - microbial degradation - rumen metabolism - rumen fermentation - models - fatty acids - biochemical pathways - animal nutrition - nutrition physiology - melkkoeien - methaan - emissie - microbiële afbraak - pensmetabolisme - pensfermentatie - modellen - vetzuren - biochemische omzettingen - diervoeding - voedingsfysiologie
Methane (CH4) is a greenhouse gas (GHG) with a global warming potential of 28 CO2 equivalents. The livestock sector was estimated to emit 7.1 gigatonnes of CO2 equivalents, which is approximately 14.5% of total global anthropogenic GHG emissions. Enteric CH4 production is the main source of GHG emissions from dairy cattle, representing 46% of the global GHG emissions in dairy supply chains. Dairy production has great value in view of the ability of ruminants to effectively turn human inedible biomass into human edible food and to produce food from non-arable land. Consequently, there is an urgent need to develop strategies to decrease dairy cattle enteric CH4 emission. Evaluation of these strategies requires meticulous quantification and increased understanding of anaerobic fermentation and methanogenesis in the rumen ecosystem. The overall aim of this PhD research was, therefore, to quantitatively evaluate enteric CH4 emission from dairy cows as affected by feeding and rumen microbial metabolism.
A meta-analysis was performed to quantify relationships between enteric CH4 yield (per unit of feed and unit of milk) and milk FA profile in dairy cattle and to develop equations to predict CH4 yield based on milk FA profile of cows fed a wide variety of diets. Various milk FA concentrations were significantly or tended to be positively or negatively related to CH4 yield per unit of feed or milk. Mixed model multiple regression resulted in various milk FA included in optimal equations to predict CH4 yield per unit of feed and per unit of milk. These regression equations indicated a moderate potential for using milk FA profile to predict CH4 yield.
For the development of a mechanistic model of CH4 production in the rumen, the thermodynamic control of pH2 on reaction rates of specific fermentation pathways, NADH oxidation and methanogenesis was theoretically explored. This control was determined using the thermodynamic potential factor (FT), which is a dimensionless factor that corrects a predicted kinetic reaction rate for the thermodynamic control exerted. The thermodynamic feasibility of these microbial conversions showed that the control of pH2 on individual VFA produced and associated yield of H2 and CH4 cannot be explained without considering NADH oxidation, with a considerable effect of pH.
For obtaining experimental support of the conclusions drawn from the theoretical exploration, diurnal patterns of gaseous and dissolved metabolite concentrations in the bovine rumen, H2 and CH4 emitted, and the rumen microbiota were monitored. In addition, the effect of dietary inclusion of linseed oil on these patterns was assessed. An in vivo experiment with rumen cannulated dairy cows was performed to study the anaerobic metabolism and the microbiota composition in the rumen. A 100-fold increase in pH2 in the rumen headspace was observed at 0.5 h after feeding, followed by a decline. Qualitatively similar patterns after feeding were observed for H2 and CH4 emission, ethanol and lactate concentrations, and propionate molar proportion, whereas an opposite pattern was seen for acetate molar proportion. Associated with these patterns, a temporal biphasic change in the microbial composition was observed as based on 16S ribosomal RNA with certain taxa specifically associated with each phase. Bacterial concentrations were affected by time and increased by linseed oil supplementation. Archaeal concentrations tended to be affected by time and were not affected by diet, despite linseed oil supplementation tending to decrease the partial pressure and emission of CH4 and tending to increase propionate molar proportion. The various diurnal profiles that were monitored support the key role of the NAD+ to NADH ratio in rumen fermentation and the importance of diurnal dynamics when understanding VFA, H2 and CH4 production.
A dynamic mechanistic model was developed, in which the thermodynamic control of pH2 on VFA fermentation pathways, and methanogenesis in the bovine rumen are incorporated. The model represents substrate degradation, microbial fermentation and methanogenesis in the rumen, with the type of VFA formed to be controlled by the NAD+ to NADH ratio, which in turn is controlled by pH2. Feed composition and feed intake rate representing a twice daily feeding regime were used as model input. The model predicted a marked peak in pH2 after feeding that rapidly declined in time. This peak in pH2 caused a decrease in NAD+ to NADH ratio followed by an increased propionate molar proportion at the expense of acetate molar proportion. In response to feeding, the model predicted a sudden increase and a steady decrease in CH4 production in time. The pattern of CH4 emission rate followed the patterns of pH2 and H2 emission rate, but its magnitude of increase in response to feeding was less pronounced. A global sensitivity analysis indicated the parameter that determines the NADH oxidation rate to explain the most substantial part of the variation of predicted daily CH4 emission. The modeling effort provides the integration of more detailed knowledge than accomplished in previous rumen fermentation models and enables assessment of diurnal dynamics of rumen metabolic pathways yielding VFA, H2 and CH4.
For assessing the general value of the research reported in this thesis, the potential for predicting enteric CH4 emission from dairy cattle based on milk FA profile was discussed in the light of published studies and compared with empirical modeling of enteric CH4 based on feed input. Moreover, the concept of NAD-controlled fermentation was considered in a more general perspective by comparing the rumen ecosystem with bioreactor systems. Furthermore, the feasibility of the developed models as an alternative for IPCC tiered approaches was explored. In conclusion, the research reported in this thesis contributes to an increased understanding of rumen fermentation and microbial metabolism, and has provides a basis to further improve prediction models of enteric CH4 emissions from dairy cattle.
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.
Praktijkproef onderwaterdrains Wormer- en Jisperveld
Akker, Jan van den; Diggelen, J.M.H. van; Houwelingen, Karel van; Kleef, Jan van; Pleijter, Matheijs ; Smolders, A.J.P. ; Turlings, L.G. ; Wielen, S. van der - \ 2016
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2765) - 67
drainage - grondwaterstand - bodemdaling - veengronden - emissie - evapotranspiratie - noord-holland - drainage - groundwater level - subsidence - peat soils - emission - evapotranspiration - noord-holland
Due to grassland evapotranspiration groundwater levels can be lowered decimeters below ditch water
level. Use of submerged drains reduces the lowering of groundwater levels and so peat oxidation and
subsidence and CO2 and N2O emissions. Submerged drains proved to increase the bearing capacity,
however, also the penetration resistance for a meadowbird beak increased. The capacity to capture
rain shower events increased. Groundwater and ditch water quality slightly improved. The infiltration
of ditch water increased considerably, however, was less than expected. Probably this is caused by a
hindered infiltration into the drain by sludge in the ditch. The use of a collector drain to regulate the
inlet is recommended.
Rekenregels voor de enterische methaan-emissie op het melkveebedrijf en reductie van de methaan-emissie via mesthandling, het handelings-perspectief van het voerspoor inzichtelijk maken met de Kringloopwijzer
S̆ebek, L.B. ; Mosquera, J. ; Bannink, A. - \ 2016
Wageningen : Wageningen Livestock Research (Livestock Research rapport 976) - 65
methaan - emissie - dierlijke meststoffen - emissiereductie - melkveehouderij - methane - emission - animal manures - emission reduction - dairy farming
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
Regionalisatie van gegevens over het landelijk gebruik van gewasbeschermingsmiddelen : een verkenning voor de EmissieRegistratie
Kruijne, R. - \ 2016
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2763) - 61
pesticiden - gezamenlijke statistieken - landbouwstatistieken - emissie - nederland - pesticides - aggregate statistics - agricultural statistics - emission - netherlands
Financiële prikkels in de landbouw voor verbetering van de waterkwaliteit
Bergevoet, Ron ; Bondt, Nico ; Lauwere, Carolien de; Buurma, Jan ; Linderhof, Vincent ; Rijk, Piet - \ 2016
Wageningen : LEI Wageningen UR (Rapport / LEI Wageningen UR 2016-033) - ISBN 9789462577794 - 89
waterkwaliteit - waterverontreiniging - landbouw - financiële ondersteuning - emissie - nederland - water quality - water pollution - agriculture - financial support - emission - netherlands
While many instruments have already been implemented in various chains in order to limit the emission of pollutants into water, only a fraction of the existing instruments are economic in nature, and very few are geared towards the ‘polluter pays’ principle (as applied in this study). Despite this, agriculture and horticulture in general, and certain sectors in particular, incur expenses in their limiting of noxious substances. There is nevertheless potential to utilize new instruments in order to give further effect to the ‘polluter pays’ principle. These instruments could be most effectively implemented on a company level and/or during the removal of pollutants. New instruments must not be introduced in isolation; instead, an optimum mix must be created in conjunction with other instruments, both existing and new. Further research ought to shed light on the compatibility of proposed instruments within existing policy frameworks as well as in which areas there is a need for entirely new instruments to be developed.
Vergelijking tussen gangbaar en emissieloos teeltsysteem : waterefficiënte Emissieloze Kas
Os, Erik van; Ruijven, Jim van; Janse, Jan ; Beerling, Ellen ; Staaij, Marieke van der; Kaarsemaker, Ruud - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1406) - 62
paprika's - capsicum annuum - teelt onder bescherming - kasgewassen - glasgroenten - glastuinbouw - emissiereductie - emissie - stikstof - fosfaat - voedingsstoffen - pesticiden - sweet peppers - capsicum annuum - protected cultivation - greenhouse crops - greenhouse vegetables - greenhouse horticulture - emission reduction - emission - nitrogen - phosphate - nutrients - pesticides
Stricter legislation forces growers to decrease discharge of water with nitrogen, phosphate and plant protection products. A demonstration was set-up to compare emission free cultivation with a traditional growing method. Goal was to achieve a comparable yield and quality. Essential differences were disinfection of rainwater, ring pipes for drip irrigation, no discharge of first drain in cultivation, a filter without rinsing and weekly analysis of the nutrient solution. It appeared that production and quality were similar as were other climate parameters. Water use was higher in emission free crop, discharge was 4% in traditional crop realizing 152 kg N discharge per ha per year, which was more than the allowed 133 kg. Specific end cultivation strategy is useful to decrease nitrogen and phosphate stored in slabs and stock containers.
Goed Gietwater Werkpakket 3, taak 2 Industrieelonderzoek naar waterkringloopsluiting in opkweekbedrijven
Appelman, W.A.J. ; Brouwer, J.G.H. ; Blok, C. ; Maas, A.A. van der; Staaij, M. van der; Beerling, E.A.M. ; Meeuwsen, B. - \ 2016
Zeist : TNO - 61
waterverontreiniging - emissie - emissiereductie - glastuinbouw - voedingsstoffen - waterbeheer - afvalwater - hergebruik van water - water pollution - emission - emission reduction - greenhouse horticulture - nutrients - water management - waste water - water reuse
Efficiënt omgaan met water speelt voor biologische en niet-biologische opkweekbedrijven van plantmateriaal een steeds grotere rol. Toenemende en strengere eisen met betrekking tot lozing van water en de emissie van nutriënten en gewasbeschermingsmiddelen naar het oppervlaktewater vragen nieuwe maatregelen. Overheden en de glastuinbouwsector hebben als doelstelling om de emissies van de glastuinbouwsector via het waterspoor in 2027 nagenoeg tot nul te reduceren waarbij er in 2018 al maatregelen moeten worden genomen met betrekking tot gewasbeschermingsmiddelen. Het doel van het Goed Gietwater project is om middels industrieel onderzoek te komen tot een vergaande waterkringloopsluiting in de opkweeksector. Met een geoptimaliseerd watermanagement en behandeling van het overtollige gietwater kunnen water en nutriënten worden teruggewonnen en emissies van nutriënten en gewasbeschermingsmiddelen naar het oppervlaktewater worden voorkomen.
Low Emission Feed : using feed additives to decrease methane production in dairy cows
Klop, G. - \ 2016
Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Jan Dijkstra; Andre Bannink. - Wageningen : Wageningen University - ISBN 9789462578944 - 168
feeds - emission - feed additives - dairy cows - methane production - nitrates - docosahexaenoic acid - milk composition - voer - emissie - voedertoevoegingen - melkkoeien - methaanproductie - nitraten - docosahexaeenzuur - melksamenstelling
Research into manipulating methane (CH4) production as a result of enteric fermentation in ruminants currently receives global interest. Using feed additives may be a feasible strategy to mitigate CH4 as they are supplied in such amounts that the basal diet composition will not be largely affected. The latter is relevant because ruminants have the capacity to convert human inedible feedstuffs into human edible energy and protein. However, the application of CH4 mitigation feed additives may be hampered by several negative side effects including trade-offs with other environmental impacts, negative effects on animal performance, and lack of persistency of the mitigating effect. The research described in this thesis addresses both the mitigating effect of feed additives as well as its persistency. The main focus was on investigating additivity of the CH4 mitigating effect of feed additives, on the adaptation of rumen microbes to long term feeding of feed additives, and on exploring the potential of rotational feeding of additives to avoid (or reduce) microbial adaptation.
In an experiment with lactating dairy cows in climate respiration chambers to study potential interactions between the effects of feeding nitrate and docosahexaenoic acid (DHA; C22:6 n-3) on enteric CH4 production, the effects of nitrate and DHA on CH4 yield [g/kg dry matter intake (DMI)] and CH4 intensity [g/kg fat- and protein- corrected milk (FPCM)], were additive (Chapter 2). Nitrate decreased CH4 irrespective of the unit in which it was expressed, and the average decline in CH4 emission corresponds to 85% of the stoichiometric potential of nitrate to decrease CH4. Feeding DHA had no effect on CH4 yield, but resulted in a higher CH4 intensity, because of milk fat depression. The interaction effect between nitrate and DHA on fiber digestibility indicated that negative effects of nitrate on apparent total tract digestibility of nutrients were alleviated by DHA, probably due to an altered feed intake pattern.
Using an isotope measurement protocol in the same study, it was demonstrated that effects of nitrate as a CH4 mitigating feed additive on fiber degradation in the rumen can be detected by evaluating diurnal patterns of 13C enrichment of exhaled CO2 (Chapter 3). Feeding nitrate, but not DHA, resulted in a pronounced increase in 13C enrichment of CO2 in the first 3 to 4 h after feeding only. Results support the hypothesis that effects of a feed additive on the rate of fiber degradation in the rumen can be detected by evaluating diurnal patterns of 13C enrichment of CO2. A prerequisite for this detection method is that the main ration components differ in natural 13C enrichment (e.g., C3 and C4 plants), and in content of the nutrients that are expected to be involved in a shift in fermentation (e.g., starch and fiber) or in degradability of a nutrient.
In a combined in vivo and in vitro trial, the adaptation to CH4 mitigating feed additives, viz. an essential oil blend or lauric acid (C12:0), compared with a control diet was first investigated using the in vitro gas production technique during the period that lactating cows were adapting to certain feed additives (Chapter 4). Rumen fluid was collected from each cow at several days relative to the introduction of the additives in the diets and used as inoculum for the gas production experiment with each of the three different substrates that reflected the treatment diets offered to the cows. The feed additives in the donor cow diet had a stronger effect on in vitro gas and CH4 production than the same additives in the incubation substrate. From day 4 onwards, the C12:0 diet persistently reduced gas and CH4 production, total volatile fatty acid concentration, acetate molar proportion and in vitro organic matter degradation, and increased propionate molar proportion. In contrast, in vitro CH4 production was reduced by the essential oils diet on day 8, but not on days 15 and 22. In line with these findings, the molar proportion of propionate in fermentation fluid was higher, and that of acetate smaller, for the essential oils diet than for the control diet on day 8, but not on days 15 and 22. Overall, the data indicate a transient effect of the essential oils on CH4 production, which may indicate microbial adaptation, whereas the CH4 mitigating effect of C12:0 persisted. It is recommended that this phenomenon is considered in the planning of future studies on the mitigation potential of feed additives in vitro.
In a follow-up in vivo study, it was investigated whether the alternate feeding of two CH4 mitigating feed additives with a different mode of action (viz. C12:0 and a blend of essential oils) would result in a persistently lower CH4 production compared to feeding a single additive over a period of 10 weeks. The experiment comprised a pre-treatment period and three two-week measurement periods, with two periods of 2 weeks in between in which CH4 emission was not measured. Cows received either continuously the essential oil blend, or both the essential oil blend and C12:0 following a weekly rotation schedule (Chapter 5). Both CH4 yield and CH4 intensity changed over time, but were not affected by treatment. Methane yield and intensity were significantly lower (12 and 11%, respectively) in period 1 compared with the pre-treatment period, but no significant difference relative to the pre-treatment period was observed in period 3 (numerically 9 and 7% lower, respectively) and in period 5 (numerically 8 and 4% lower, respectively). These results indicate a transient decrease in CH4 yield and intensity in time, but no improvement in extent or persistency of CH4 reduction due to rotational feeding of essential oils and C12:0 in lactating dairy cows. However, there were indications that the concept of rotation may be effective and warrants further investigation.
The additives and concepts tested in this thesis are applied under specific experimental conditions. More mechanistic understanding is required to predict the response of the same additives when supplemented to other basal diets or cows in a different physiological state. Trade-offs in environmental impact, and effects on cow health and performance, and on milk processing parameters and food safety are important aspects to consider in future research on the application of feed additives as CH4 mitigation strategy.