Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    How to achieve resource use efficiency in integrated food and biobased value chains?
    Annevelink, E. ; Gogh, J.B. van; Bartels, P.V. ; Broeze, J. ; Dam, J.E.G. van; Groot, J.J. ; Koenderink, N.J.J.P. ; Oever, M.J.A. van den; Snels, J.C.M.A. ; Top, J.L. ; Willems, D.J.M. - \ 2017
    Wageningen : Wageningen Food & Biobased Research (Wageningen Food & Biobased Research report 1720) - ISBN 9789463431163 - 23
    resources - biobased economy - food chains - food biotechnology - biomass - change - sustainability - value chain analysis - efficiency - use efficiency - food - resource management - integrated systems - hulpbronnen - biobased economy - voedselketens - voedselbiotechnologie - biomassa - verandering - duurzaamheid (sustainability) - waardeketenanalyse - efficiëntie - gebruiksefficiëntie - voedsel - hulpbronnenbeheer - geïntegreerde systemen
    Balancing options for shrimp farming : a landscape approach to investigate the future of shrimp farming in the Mekong Delta
    Joffre, O.M. - \ 2015
    Wageningen University. Promotor(en): Johan Verreth; Arnold Bregt, co-promotor(en): Roel Bosma. - Wageningen : Wageningen University - ISBN 9789462574984 - 196
    garnalenteelt - schaal- en schelpdierenteelt - kustgebieden - milieueffect - landschap - aquacultuur - mangroves - middelen van bestaan - hulpbronnengebruik - geïntegreerde systemen - duurzaamheid (sustainability) - mekong - delta's - shrimp culture - shellfish culture - coastal areas - environmental impact - landscape - aquaculture - mangroves - livelihoods - resource utilization - integrated systems - sustainability - mekong river - deltas

    Balancing options for shrimp farming

    A landscape approach to investigate the future of shrimp farming in the Mekong Delta

    Olivier Joffre

    While providing an option for development in coastal areas, shrimp farming is usually associated with high environmental cost due to the loss of mangrove forest and high social cost as farmers suffer heavy financial losses due to disease outbreaks. Planning shrimp farming requires to integrate risk as well as social and environmental cost. This thesis, using the Mekong Delta as a case, presents an approach to investigate, with local stakeholders, options to plan a resilient and sustainable shrimp farming sector. First, Olivier Joffre analyzed the different shrimp production systems from economic point of view before analyzing farmer’s strategies and providing insights on drivers that will push or, at the opposite, constraint farmers to choose integrated mangrove shrimp systems. This knowledge was integrated in an Agent Based Model (ABM) that was calibrated using Role Playing Games (RPG).

    The effect of future scenarios and different policies on the farmers’ decisions was tested using a combination of RPG and ABM. For one coastal district of the Mekong Delta, the results showed that promotion of intensification of shrimp production has a high social cost and decreases the total production in the study area after 10 years. Policies for supporting the spread of integrated mangrove-shrimp systems, such as Payment for Ecosystem Services, or access to an organic value chain, are not strong enough to influence farmers’ decision toward adopting these systems. Without any adaptation to climate change a sharp decrease of the production is expected. The approach brought local farmers’ knowledge to the attention of decision makers.

    Opbrengst op peil met organische stof
    Haan, J.J. de - \ 2014
    Boerderij 99 (2014)29. - ISSN 0006-5617 - p. 72 - 72.
    akkerbouw - bemesting - organische stof - opbrengsten - bodemchemie - bedrijfssystemen - biologische landbouw - geïntegreerde systemen - proeven op proefstations - veldproeven - zandgronden - de peel - arable farming - fertilizer application - organic matter - yields - soil chemistry - farming systems - organic farming - integrated systems - station tests - field tests - sandy soils - de peel
    Extra aanvoer van organische stof compenseert een lagere aanvoer van mineralen. De gewasopbrengst blijft op peil en nitraatuitspoeling vermindert. Dit project 'Bodemkwaliteit op zandgrond’ richt zich op ontwikkeling van maatregelen voor duurzaam bodembeheer op zandgrond op het gebied van organischestofbeheer en grondbewerking. Het onderzoek wordt uitgevoerd op het proefbedrijf PPO Vredepeel.
    Concurrentie voor Braziliaanse ethanol
    Visser, C.L.M. de - \ 2012
    Kennis Online 9 (2012)april. - p. 12 - 12.
    bio-energie - biobrandstoffen - biobased economy - bioethanol - geïntegreerde systemen - biogas - warmte - energieproductie in de landbouw - bioenergy - biofuels - biobased economy - bioethanol - integrated systems - biogas - heat - agricultural energy production
    Een Nederlandse boer kan concurreren met een Braziliaanse bio-ethanolfabriek. Voorwaarde is wel dat hij zoveel mogelijk energie perst uit elke stengel stro of korrel maïs. In Lelystad zoeken onderzoekers naar de meest efficiënte combinatie van algenteelt, mestvergisting en de productie van bio-ethanol.
    De teelt van tomaten
    Maaswinkel, Ruud - \ 2011
    solanum lycopersicum - tomatoes - greenhouse horticulture - plant protection - cultivation manuals - greenhouse vegetables - fruit vegetables - integrated systems - integrated pest management
    Vulnerability and resilience of competing land-based livelihoods in south eastern Zimbabwe
    Murungweni, C. - \ 2011
    Wageningen University. Promotor(en): Ken Giller; E.M.A. Smaling, co-promotor(en): Jens Andersson; Mark van Wijk. - [S.l.] : S.n. - ISBN 9789085859796 - 141
    middelen van bestaan - duurzaamheid (sustainability) - droogte - geïntegreerde systemen - plattelandsontwikkeling - diervoedering - neorautanenia amboensis - zimbabwe - livelihoods - sustainability - drought - integrated systems - rural development - animal feeding - neorautanenia amboensis - zimbabwe

    Key words: vulnerability; resilience; livelihood; drought; Great Limpopo Transfrontier Conservation Area; south eastern Zimbabwe.

    Vulnerability and resilience have emerged as powerful analytical concepts in the study of socio-ecological systems. In this research these concepts are used to enhance our understanding of heterogeneous rural livelihoods in a semi-arid area on the western border of protected wildlife areas in Zimbabwe’s southeast lowveld. The purpose of this thesis is to develop a methodological approach that helps understanding the vulnerability of rural livelihoods to change and relate this to adaptive mechanisms employed by people to cope with the resulting change. Although most households in the study area keep livestock, practice arable farming, and receive remittances, they differ in terms of their dependency on cattle, cropping, and non-farm and off-farm activities, especially in years of drought. Households most dependent on livestock – the cattle-based livelihood type – generally cope with hazards by selling cattle. Households of the crop-based livelihood type strive to spread the risk of crop failure by cropping across the landscape, ranging from flood plains to uplands on the interfluves. Households of the non-farm livelihood type rely for their survival on paid employment outside the study area, mostly of households’ members working in South Africa. Fuzzy Cognitive Mapping (FCM) was used to assess the vulnerability of the three livelihood types to different hazards. The vulnerability analysis shows that policies relating to the permeability and/or enforcement of protected area boundaries can strongly aggravate the effects of other external influences, such as drought or climate change. To cope with drought-induced fodder shortages, people of cattle-based households have recently started to use Neorautanenia amboensis (Schinz). This tuber shrub, locally known as Zhombwe, is now saving many cattle from death in periods of drought, thus reducing livestock keeping households vulnerability to drought. This thesis shows the anthelmintic properties of Zhombwe; its distribution in the field was quantified. Crop experiments explored adaptive strategies which can be used by the households of the crop-based livelihood type to increase food self-sufficiency. Results show that by making better use of different landscape units in the area food production can be increased, both in good and bad rainfall years. By applying a method like FCM and by analysing quantitatively different options for increasing the resilience of the local households, this thesis shows that it is key to take into account the heterogeneity of rural households in an area, as adaption options differ strongly between them.

    Geïntegreerde en biologische teelt van vaste planten
    Dalfsen, Pieter van - \ 2009
    organic farming - perennials - aconitum - phlox - integrated systems - floriculture - weed control - soil organic matter - rorippa sylvestris - plant protection - fertilizer application
    Vf-schurftresistentie houdt stand door resistentiemanagement
    Maas, M.P. van der - \ 2009
    ziekteresistentie - plaagresistentie - appels - geïntegreerde plagenbestrijding - geïntegreerde systemen - resistentieveredeling - disease resistance - pest resistance - apples - integrated pest management - integrated systems - resistance breeding
    Poster over 12 jaar Vf-schurftresistente appelrassen. Vf-schurftresistentie houdt stand door resistentiemanagement.
    Resultaten geïntegreerd systeem 2007
    Geel, W.C.A. van; Haan, J.J. de; Dam, A.M. van - \ 2008
    Informatieblad Nutriënten Waterproof 2008 (2008)14. - p. 1 - 2.
    akkerbouw - geïntegreerde systemen - rotaties - allium porrum - lilium - aardappelen - triticale - zea mays - suikerbieten - uitspoelen - voedingsstoffen - stikstof - fosfaat - grondwater - arable farming - integrated systems - rotations - allium porrum - lilium - potatoes - triticale - zea mays - sugarbeet - leaching - nutrients - nitrogen - phosphate - groundwater
    Dit infoblad beschrijft de resultaten van het geïntegreerde systeem: een akkerbouwrotatie met prei en lelie erin. Het project Nutriënten Waterproof (NWP) richt zich op de ontwikkeling van duurzame bedrijfssystemen op zandgrond met een minimaal verlies van nutriënten naar het grond- en oppervlaktewater én een goede opbrengst en kwaliteit van de gewassen. Om dit te bereiken worden vanaf 2005 diverse innovatieve maatregelen op semi-praktijkschaal beproefd in vier bedrijfssystemen op PPO-proefbedrijf Vredepeel.
    Resultaten geïntegreerd systeem 2006
    Geel, W.C.A. van; Haan, J.J. de - \ 2007
    Lelystad : PPO AGV (Informatieblad Nutriënten Waterproof 11)
    akkerbouw - teeltsystemen - geïntegreerde systemen - zandgronden - rotaties - voedingsstoffen - gewaskwaliteit - duurzaamheid (sustainability) - innovaties - proeven op proefstations - preien - allium porrum - lilium - lelies - geïntegreerde bedrijfssystemen - vollegrondsteelt - arable farming - cropping systems - integrated systems - sandy soils - rotations - nutrients - crop quality - sustainability - innovations - station tests - leeks - allium porrum - lilium - lilies - integrated farming systems - outdoor cropping
    Het project Nutriënten Waterproof (NWP) richt zich op de ontwikkeling van duurzame bedrijfssystemen op zandgrond met een minimaal verlies van nutriënten naar het grond- en oppervlaktewater én een goede opbrengst en kwaliteit van de gewassen. Om dit te bereiken worden diverse innovatieve maatregelen op semi-praktijkschaal beproefd in vier bedrijfssystemen op PPO-proefbedrijf Vredepeel. Dit infoblad beschrijft de resultaten van het geïntegreerde systeem: een akkerbouwrotatie met prei en lelie erin
    Een verdere professionalisering van het agrarische ondernemerschap : beschrijving en evaluatie van partipatieve trajecten met biologische en geïntegreerde ondernemers
    Waal, B.H.C. van der; Peppelman, G. ; Roelofs, P.F.M.M. ; Smit, A.B. ; Voort, M.P.J. van der; Wekken, J.W. van der; Wolf, P.L. de; Jukema, N.J. ; Schoorlemmer, H.B. - \ 2007
    Wageningen : Praktijkonderzoek Plant & Omgeving B.V. (PPO publicatie 361) - 43
    boeren - agrarische bedrijfsvoering - biologische landbouw - geïntegreerde systemen - bedrijfssystemen - bedrijfssystemenonderzoek - ondernemerschap - nederland - geïntegreerde bedrijfssystemen - farmers - farm management - organic farming - integrated systems - farming systems - farming systems research - entrepreneurship - netherlands - integrated farming systems
    Fishponds in farming systems
    Zijpp, A.J. van der; Verreth, J.A.J. ; Quang Tri, Le; Mensvoort, M.E.F. van; Bosma, R.H. ; Beveridge, M.C.M. - \ 2007
    Wageningen : Wageningen Academic Publishers - ISBN 9789086860135 - 311
    visvijvers - visteelt - bedrijfssystemen - geïntegreerde systemen - landbouw - duurzaamheid (sustainability) - kringlopen - fish ponds - fish culture - farming systems - integrated systems - agriculture - sustainability - cycling
    Throughout the last century, specialisation and intensification were buzz words for farmers in the Western world. However, this approach has not resulted in sustainable development as evidenced by the fact that scientists now need to create technologies to reduce negative impacts. In this book we demonstrate that an alternative exists. Case studies from Bangladesh, Thailand, and Vietnam show that integration and diversification increase both farm productivity and farmers' incomes. By adopting a participatory approach, farmers and scientists identified a range of technologies that strengthen the positive impacts of integrated aquaculture-agriculture systems for the environment. This book is a collection of refereed papers on a controversial subject in agricultural development. Arguing that sustainability of fish culture in ponds needs a new paradigm - feed the pond to grow fish - two chapters focus on nutrient cycling in such systems. Another chapter makes the case for breeding Nile tilapia for resource poor farmers and presents practical options to avoid the pitfalls that arise from natural tilapia mating in low-input ponds. The book contains chapters on livelihood and development aspects and ends with a general discussion completing the picture of the integrated aquaculture-agriculture systems. Overall it composes a review which addresses one of the key issues of the new century: how to sustainably produce food without compromising environmental integrity.
    Krachtvoer heeft grote invloed op milieubelasting melkveehouderij
    Thomassen, M.A. ; Boer, I.J.M. de; Smits, M. ; Iepema, G. ; Calker, K.J. van; Werkman, R. ; Jansen, J. ; Gravendijk, L.M. 's - \ 2007
    V-focus 1 (2007). - ISSN 1574-1575 - p. 20 - 22.
    melkveehouderij - landbouw bedrijven - biologische landbouw - geïntegreerde systemen - verontreiniging - energiegebruik - landgebruik - agrarische bedrijfsvoering - milieuhygiëne - dairy farming - farming - organic farming - integrated systems - pollution - energy consumption - land use - farm management - environmental hygiene
    Onderzoekers van Wageningen UR hebben samen met enkele projectteams een levenscyclusanalyse uitgevoerd op gangbare, gangbaar-plus en biologische melkveebedrijven. Hiermee wordt de totale milieubelasting in kaart gebracht. De milieueffecten landgebruik, energieverbruik, verzuring, vermesting en het broeikaseffect zijn onderzocht
    EffectModellering Indicatoren, Gebruikers en Management (EMIGMA)
    Meesters, H.W.G. - \ 2006
    tendensen - milieubeheer - geïntegreerde systemen - indicatoren - analyse - beslissingsmodellen - natuurbeheer - trends - environmental management - integrated systems - indicators - analysis - decision models - nature management
    Dit pamflet geeft een korte uitleg van EMIGMA, 'EffectModellering Indicatoren, Gebruik en Management', dat vanaf 2004 is ontwikkeld door Alterra voor het Milieu- en Natuurplanbureau (MNP). EMIGMA integreert trends in indicatoren, gebruiksfuncties en beleidsmaatregelen. De voordelen van EMIGMA zijn een centrale database met gegevens, snelle beschikbaarheid, gebruiksvriendelijkheid, analyse en vergelijking van trends
    Fish waste management by conversion into heterotrophic bacteria biomass
    Schneider, O. - \ 2006
    Wageningen University. Promotor(en): Johan Verreth, co-promotor(en): V. Sereti. - [S.l. ] : S.n. - ISBN 9789085044130 - 160
    vismest - dierlijk afval - bacteriën - heterotrofe micro-organismen - biomassa productie - conversie - voer - aquacultuur - intensieve dierhouderij - geïntegreerde systemen - duurzaamheid (sustainability) - fish manure - animal wastes - bacteria - heterotrophic microorganisms - biomass production - conversion - feeds - aquaculture - intensive husbandry - integrated systems - sustainability

    Just as all other types of animal production, aquaculture produces waste. This waste can be managed outside the production system, comparable to terrestrial husbandry systems. However, particularly recirculation aquaculture systems (RAS) are suited to manage waste within the system. In this case, processes have to be selected to convert the waste into a re-usable product. Dissolved and solid waste conversion by heterotrophic bacteria is one of these processes. In the present study, the potential of the latter process was investigated. An operational scheme was followed, which contained five steps: (1) to evaluate nutrient flows in integrated aquaculture systems, (2) to select and to investigate a conversion process, (3) to improve the process and analyze its sensitivity, (4) to evaluate the product suitability, (5) to derive the kinetics, reactor design, and to determine the integration possibilities into RAS.

    In chapter 2 nutrient flows, conversions and waste management were evaluated, which are taking place in integrated intensive aquaculture systems. In these systems, fish is cultured next to other organisms, which are converting nutrients, which would be otherwise discharged. These conversions were evaluated based on nitrogen (N) and phosphorous (P) balances using a mass balance approach. In the reviewed examples, fish culture alone retained 20-50% feed N and 15-65% feed P. The combination of fish culture with phototrophic conversion increased nutrient retention of feed N by 15-50% and of feed P by up to 53%. If in addition herbivore consumption was included, then the gained nutrient retention decreased by 60-85% feed N and 50-90% feed P. The conversion of nutrients into bacteria and detrivorous worm biomass contributed only to a smaller extent (e.g. 7% feed N and 6% feed P and 0.06% feed N 0.03xl0"3% feed P, respectively). AIl integrated modules had their specific limitations, which were related to uptake kinetics, nutrient preference, unwanted conversion processes and abiotic factors and implications.

    Chapters 3 to 5 focused on the experimental production of heterotrophic bacteria biomass on carbon (C) supplemented fish waste under different operational conditions. The results covered step two and three in the operational scheme.

    In chapter 3, the drum filter effluent from a RAS was used as substrate to produce heterotrophic bacteria in suspended growth reactors. Effects of organic C supplementation (0, 0.9, 1.7, 2.5gC/l as sodium acetate) and of hydraulic retention times (HRT: 1 l-lh) on bacteria biomass production and nutrient conversion were investigated. Bacteria production, expressed as VSS (volatile suspended solids) was enhanced by organic C supplementation, resulting in a production of 55-125gVSS/kg fish feed (0.2-0.5gVSS/gC). Maximum observed crude protein production was ~100g protein/kg fish feed. The metabolic maintenance costs were 0.08Cmol/Cmol h"', and the maximum growth rate was 0.25-0.5h"'. Approximately, 90% of the inorganic nitrogen and 80% of ortho-phosphate-phosphorus were converted.

    The influence of nitrogenous waste on bacteria yields was investigated in chapter 4. RAS effluents are rich in nitrate and low in total ammonia nitrogen (TAN). This might result in 20% lower bacteria yields, because nitrate conversion into bacteria is less energy efficient than TAN conversion. In this chapter, the influence of TAN concentrations (1, 12, 98, 193, 257mgTAN/l) and stable nitrate-N concentrations (174+29mgfl) on bacteria yields and N conversions was investigated in a RAS under practical conditions. The effluent slurry was supplemented with 1.7gC71 sodium acetate, due to C deficiency, and was converted continuously in a suspended bacteria growth reactor (6h HRT). TAN utilization did not result in different yields compared to those for nitrate (0.24-0.32gVSS/gC, p=0.763). However, TAN was preferred compared to nitrate and was converted to nearly 100%, independently of TAN concentrations. TAN and nitrate conversion rates differed significantly for increasing TAN levels (p<0.000 and p=0.012), and were negatively correlated. It seems, therefore, equally possible to supply the nitrogenous substrate for bacteria conversion as nitrate or as TAN. Because in RAS, nitrate is the predominant N form in the waste, the bacteria reactor can safely be integrated into an existing RAS as end of pipe treatment.

    In chapter 5, sodium acetate, which was used in chapter 3 and 4 was replaced by molasses as organic C supplement. The effect of molasses as alternative C source on bacteria productions and yields was investigated. One bacteria reactor (3.5 1) was connected to the drum filter (filter mesh size 60???) outlet of a recirculation system in a continuous flow (HRT: 6h). The different supplementation levels of molasses were 0.0, 3.2, 5.8, 7.8, 9JgCfl/d. For the maximum flux, the VSS and crude protein production were about 168gVSS and 95g crude protein per kg feed. The maximum conversion of nitrate and ortho-phosphate was 24g NO3-N and 4gP/kg feed, a conversion of 90% of the inorganic nitrogenous waste and 98% of the ortho-phosphate-P. Furthermore the maximum substrate removal rate and the half saturation constant (K8) were determined (1.62gC/l^i and 0.097gC/l respectively). The maximum specific removal rate was 0.31gC/gVSS/h and the related K5 was 0.008gC/l. The observed growth rate reached a maximum for C fluxes higher than 8g/l/d.

    Chapter 6 and 7 were focusing on the fourth step of the operational scheme (product evaluation and determination of re-use potential).

    Because the produced bacteria biomass might contain pathogens, which could reduce its suitability as feed, it was important to characterize the obtained bacteria communities under different conditions (chapter 3 to 5, reported in chapter 6). The operation conditions were: 7h hydraulic retention time versus 2h, sodium acetate versus molasses (organic C supplement), and ammonia versus nitrate (N donor). Samples were analyzed by standard biochemical tests, by 16sRNA ribotyping and ribosomal RNA gene-targeted PCR-DGGE fingerprinting combined with clone library analysis. The community of the drum filter effluent was different from the communities found in the bacteria reactors. However, all major community components were present in both the drum filter effluent and reactor broths. HRTs (7h versus 2h) influenced bacteria community resulting in a more abundant fraction of alpha proteobacterium Bioluz/ Acinetobacter at 2h HRT compared to 7h HRT (Rhizobium! Mezorhizobium). The use of molasses instead of sodium acetate changed the bacteria community from Rhizobium/ Mesorhizobium to Aquaspirillum as major component. Providing TAN in addition to nitrate as nitrogenous substrate led to the occurrence of bacteria close to Sphaerotilus, Sphingobacterium and Jonesia. From those results, it was concluded that 6-7h HRT is recommended, and that the type of substrate (sodium acetate or molasses, TAN or nitrate) is less important, and results in communities with a comparable low pathogenic risk.

    In chapter 7, the produced bacteria biomass was fed to shrimps (Litopenaeus vannamei), In total three different diets were used in a variance of a T-maze test: a commercial shrimp feed, the bacteria biomass, which was produced in the suspended growth reactors on C supplemented fish waste under conditions, comparable to those reported in chapter 3, and slurry, which was anaerobicaliy produced in a denitrification reactor. If the bacteria products would be attractive as diet, the nutrient retention of the RAS would be improved, resulting in a system, combining fish, bacteria and shrimp. The diet preference was interpreted as an expression of diet attractiveness. As a first result, shrimp were moving from an equal distribution before feeding (+/-50%, -2min), towards the feeding places (>50%, 2, 5, and 10 minutes after feeding). It was, therefore, inferred, that all bacteria biomass and commercial feed combinations were basically attractive for the shrimp. This response was not instantaneous. After feeding (2min) more than 80% of the shrimp were present at the feeding places and showed a significant preference for the commercial feed compared to the aerobically produced bacteria slurry. For the other diet combinations no significant differences could be detected for 2min. For 5 and lOmin after feeding, shrimp behavior changed from the commercial feed to the aerobically and anaerobicaliy produced bacteria biomass segments. From this study it was conc!uded that although the commercial diet was preferred above the aerobic slurry, the bacteria slurries had also attracted the shrimps. There was no unambiguous conclusion to be made regarding the preference for aerobic or anaerobic produced slurry. In chapter 8, the design of a suspended bacteria growth reactor integrated in a lOOMT African catfish farm was determined. This study integrated results from the earlier chapters to calculate the bacteria kinetics (yield=0.537gVSS/gC; endogenous decay coefficienl=0.033h^'; maximum specific growth rate=0.217h^ ; half-velocity constant=0.025g/l; and maximum rate of substrate utilization-0.404gC/gVSS*h). As part of the study a model was developed and validated. This model was used to calculate the VSS production and nutrient conversion by heterotrophic bacteria conversion for a lOOMT African catfish farm. The VSS production was 187gVSSAcg feed and the inorganic nutrients (N and P) were removed with an efficiency of 85 and 95% for a C supplementation level of 3.5gC/l (455gC/kg feed). A reactor integrated in a lOOMT farming facility would have a volume of 11m , based on a minimum HRT of6h. The production and potential re-use of heterotrophic bacteria biomass is, therefore, a prospective tool to lower nutrient discharge and to increase nutrient retention and sustainability of RAS in the future.

    De verspreiding van 5 platvissoorten en 1 roggensoort in de Noordzee
    Hofstede, R. ter - \ 2005
    IJmuiden : RIVO (Rapport / Nederlands Instituut voor Visserij Onderzoek (RIVO) C082/05) - 13
    noordzee - pleuronectiformes - karteringen - geïntegreerde systemen - onderzoeksprojecten - vangstsamenstelling - boomkorvisserij - north sea - pleuronectiformes - surveys - integrated systems - research projects - catch composition - beam trawling
    Het huidige rapport geeft een beknopte beschrijving van het ruimtelijk gebruik van de Noordzee door 5 platvisoorten en 1 roggensoort, te weten schol, tong, bot, tarbot, tongschar en sterrog. Dit wordt gedaan op basis van vangsten tijdens de Nederlandse Beam Trawl Survey (BTS) over de periode 1996-2005. Er worden kaarten getoond op Noordzee-schaal, alsmede op NCP-schaal van de gemiddelde vangstaantallen per subkwadrant (1/9 ICES-kwadrant ~ 19x19km). De gegevens zijn afkomstig uit geïntegreerd internationaal onderzoek. Onderzoeksschepen van verscheidene landen verzamelen gegevens over de verspreiding van eieren, larven, juveniele en volwassen commerciële vissoorten. Dankzij dergelijke onderzoeksreizen is het mogelijk het ruimtelijk gebruik van de Noordzee door vispopulaties in kaart te brengen.
    Milieubelasting door onkruidbestrijding in biologische, geïntegreerde en gangbare landbouw
    Weide, R.Y. van der; Riemens, M.M. - \ 2005
    Gewasbescherming 36 (2005)2. - ISSN 0166-6495 - p. 105 - 108.
    gewasbescherming - onkruidbestrijding - biologische landbouw - geïntegreerde systemen - landbouw - milieuafbraak - milieueffect - milieu - energiegebruik - herbiciden - pesticiden - akkerbouw - plant protection - weed control - organic farming - integrated systems - agriculture - environmental degradation - environmental impact - environment - energy consumption - herbicides - pesticides - arable farming
    De milieubelasting als gevolg van onkruidbestrijding in biologische, geïntegreerde en gangbare landbouwsystemen wordt met elkaar vergeleken. Het blijkt dat met name grondwater en waterleven wordt belast door het gebruik van herbiciden. Het energieverbruik van onkruidbestrijding is in een biologisch systeem het hoogst, in een geïntegreerd systeem het laagst. Uit literatuurstudie blijken de effecten van mechanische en chemische onkruidbestrijding op niet-doelorganismen voornamelijk indirect te zijn
    Coupled models for the hydrological cycle; integrating atmosphere, biosphere, and pedosphere
    Bronstert, A. ; Carrera, J. ; Kabat, P. ; Lütkemeier, S. - \ 2005
    Berlin (Germany) [etc.] : Springer - ISBN 9783540223719 - 345
    hydrologie - milieu - geïntegreerde systemen - atmosfeer - pedologie - wiskundige modellen - koppelstukken - hydrologische cyclus - biosfeer - hydrology - environment - integrated systems - atmosphere - pedology - mathematical models - couplings - hydrological cycle - biosphere
    Hydrologists, climatologists, soil scientists and environmental engineers are frequently asked to analyse complex environmental problems. It is becoming increasingly apparent that these problems usually involve feedbacks between atmospheric, ecological, and hydrological systems, as well as human society. It is often the feedbacks between systems that are of greatest interest because they may produce unanticipated responses. That is why coupling of different compartments of the Earth system has emerged as a general challenge to the modelling community. This book considers an array of state-of-the-art coupling and modelling concepts. First the relevant Earth system cycles are presented, followed by a discussion on scale issues and multiple equilibria. Inter- and intra-compartmental coupling is addressed, along with a debate on non-linearities and questions of parameterisation. Several applications are presented, where a focus is on cases where the hydrological cycle plays a central role.
    Chemische loofdoding : een knelpunt bij geïntegreerde aardappelteelt
    Bus, C.B. ; Veerman, A. ; Kempenaar, C. ; Weide, R.Y. van der - \ 2004
    Kennisakker.nl 2004 (2004)15 nov.
    aardappelen - loofvernietiging - geïntegreerde systemen - chemische behandeling - akkerbouw - potatoes - haulm destruction - integrated systems - chemical treatment - arable farming
    In een rapport ten behoeve van het ministerie van LNV worden de verschillende systemen van loofdoding van aardappelen besproken, waarbij de nadruk ligt op mogelijkheden om het gebruik van chemische loofdodingsmiddelen te beperken. Aan de orde komen onder andere: alternatieven zoals enkel loofklappen, looftrekken, loofbranden en groenrooien/onderdekken; beperking van het gebruik van de hoeveelheid chemische middelen door omschakeling van bijvoorbeeld Reglone naar Spotligtht 24 EC; in de toekomst beperking van het middelengebruik met behulp van de combinatie Crop scan en MLHD; de milieutechnische voor- en nadelen van de verschillende methoden, en de factoren die van invloed zijn op de acceptatie van alternatieven van chemische loofdoding
    Gaten in het bosbeheer
    Wijdeven, S.M.J. ; Willems, A.J.H. ; Groot Bruinderink, G.W.T.A. - \ 2004
    Vakblad Natuur Bos Landschap 1 (2004)8. - ISSN 1572-7610 - p. 18 - 19.
    bosbouw - bosbeheer - verjonging - natuurlijke verjonging - velling - kaalslag - geïntegreerde systemen - opstandskenmerken - opstandsstructuur - opstandsontwikkeling - bossen - botanische samenstelling - bosecologie - gaten in het kroondak - soortendiversiteit - biodiversiteit - bosopstanden - geïntegreerd bosbeheer - forestry - forest administration - regeneration - natural regeneration - felling - clear felling - integrated systems - stand characteristics - stand structure - stand development - forests - botanical composition - forest ecology - canopy gaps - species diversity - biodiversity - forest stands - integrated forest management
    Pleidooi voor het toepassen van grotere gaten bij de natuurlijke verjonging van bosopstanden. In de huidige praktijk wordt geïntegreerd bosbeheer veelal ingevuld door kleinschalige ingrepen, afgestemd op het opstandsniveau. Weliswaar verhoogt dit op dit schaalniveau (de plek of de opstand) de variatie, maar het leidt tot een meer uniforme situatie op het niveau van terreindelen en de beheerseenheid. Grote verjongingsgaten hebben niet alleen een specifiek effect op de soortensamenstelling en structuur van de verjonging, maar zijn ook van belang voor andere soorten, zoals kruiden, korstmossen, reptielen, insecten, vogels en grote hoefdieren, en leveren daarmee een bijdrage aan vergroting van de biodiversiteit en de belevingswaarde
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