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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    Ontsmettingsmiddel niet altijd getest op effect in plantaardige teelten : toevoeging aan druppelwater of complete installatie
    Stijger, Ineke ; Os, Erik van - \ 2016
    horticulture - greenhouse horticulture - disinfectants - nutrient solutions - trickle irrigation - disinfection - effects - adverse effects - chlorine - hydrogen peroxide - irrigation water - plant viruses - recirculating systems

    Een vertegenwoordiger rijdt het erf op, doet zijn kofferbak open en prijst een willekeurig ontsmettingsmiddel aan. Het gebeurt regelmatig, weten Wageningen UR onderzoekers Ineke Stijger en Erik van Os te vertellen. En er zijn nog steeds telers die de verkopers op hun woord geloven. “Niet veel later hebben wij ze aan de telefoon met de vraag waarom het water toch niet voldoende schoon is.” De onderzoekers roepen telers daarom op kritisch te blijven kijken naar nieuwe middelen en technieken. “Geloof de werking pas als die via onafhankelijk onderzoek is bewezen.”

    Performing drip irrigation by the farmer managed Seguia Khrichfa irrigation system, Morocco
    Kooij, S. van der - \ 2016
    Wageningen University. Promotor(en): Charlotte de Fraiture; Margreet Zwarteveen, co-promotor(en): M. Kuper. - Wageningen : Wageningen University - ISBN 9789462577626 - 166
    trickle irrigation - irrigation systems - efficiency - morocco - druppelbevloeiing - irrigatiesystemen - efficiëntie - marokko

    Drip irrigation is represented in literature and agricultural policies as a modern and water saving technology. Because this technology is often associated with ‘modern’ agriculture and development, it seems out-of-place in ‘traditional’ farmer managed irrigation systems (FMIS). Thinking along the binary modernity-tradition leaves little room for the possibility that drip irrigation and FMIS could come together in a meaningful way as they place FMIS and drip irrigation in two mutually exclusive representational categories. Yet, the water users from the Khrichfa Canal, part of the Ain Bittit Irrigation System, a ‘traditional’ FMIS in Northern Morocco, opt for ‘modern’ drip irrigation as technology of their choice. To explain this apparent contradiction this PhD thesis develops an approach to rethinking the performance of drip irrigation in the context of farmer managed irrigation systems. The question “how does drip irrigation perform?” guides this research. In irrigation engineering literature the performance of drip irrigation is centred around the notion of water use efficiency – the prime task that drip irrigation is supposed to fulfil. However, to understand drip irrigation in FMIS, a more processual and less prescriptive approach to performance is explored. Drawing on actor-network approaches, the thesis understands performance as “the art of ordering the relations and interactions between people and objects, a process of ordering which emerges from practice and which results in contingent, surprising outcomes.”

    This study starts by ‘unpacking’ the efficiency of drip irrigation by exploring what efficiency means, how the strong link between drip irrigation and efficiency was constructed, and what this association of drip irrigation as an efficient technology does. Because of its renowned efficiency, drip irrigation introduction is stimulated in many countries. Yet, efficiency is not an uncontested term. From the academic debate on efficiency complexity, it is clear that efficiency terminology is scale and context specific. Rather than studying drip irrigation with a pre-defined scale of analysis, this thesis focuses on how efficiencies, and their assumptions about scales and context, are used in irrigation projects and descriptions of drip irrigation performance. This PhD study critically engages with questions about efficiency and searches for alternative ways of understanding performance. To understand how drip irrigation and FMIS can come together in meaningful ways, this PhD study does not only re-define the performance of drip irrigation but likewise re-thinks conceptualisations of FMIS. FMIS are approached as dynamic entities that continuously change – which allows to see the introduction of drip irrigation as yet another change, rather than a disruption of ‘tradition’.

    The farmer managed Seguia Khrichfa in Northern Morocco is selected as a case study to understand how drip irrigation performs in a FMIS with a historical analysis. The Moroccan government stimulates the introduction of drip irrigation because this efficient technology addresses problems of groundwater depletion ànd supports a growth in agricultural production. In the Khrichfa area, several individual farmers have converted to drip irrigation and the water users organisation is planning for a collective drip irrigation system. The existing drip irrigation systems and the collective plans provided fertile ground for exploring how ‘modern’ drip irrigation and ‘traditional’ FMIS can go together. This thesis begins with a literature review on the efficiency of drip irrigation in Chapter 2. Chapter 3 is an analysis of what efficiencies do in the field, how efficiencies are used to re-allocate water in (drip) irrigation projects. In Chapter 4 and 5 alternative conceptualisations of performance are explored: in Chapter 4 by analysing the intimate relation between technologies and institutions, and their capacity to mutually shape each other, and in Chapter 5 the focus lies on understanding the performance of drip irrigation as emerging from the interactions between the technology and its (potential) user.

    The literature review in Chapter 2 aims to understand the scientific basis for the expectations that drip irrigation is efficient with water. Efficiency studies underscore the need for drip irrigation as a device to counter water scarcity, groundwater depletion and competition over water and align with a modernization discourse – aiming at improvement and upgrading of irrigation. The efficiency of drip irrigation is constructed at very localized experimental stations with a wide variety of efficiency terms and definitions used by different research communities. Although the term efficiency gives the impression of unity, the studies that measure and define efficiency have remarkable differences in conceptualizing water balances and measuring water flows. However, the resulting efficiency numbers are treated as if they were comparable amongst each other. This results in a widely supported consensus that drip irrigation saves water. This creation of unity might be strategic for continuation of research practices and funding, but it says little about how drip irrigation will perform in the fields of farmers. The practices of farmers are left out of the experiments reviewed in literature. Besides local farming practices more ‘context’ is left out of the equations: with water-tight plastic borders all flows in the experiments are controllable. The research on the efficiency of drip irrigation is thus very technology-centred, i.e. the performance of the technology and its capacity to bring water efficiently to plants is attributed to the material objects.

    Chapter 3 shows that efficiency numbers do have influence as they embed a promise of the creation of more water. Apparently previously ‘lost’ water would be captured, thus resulting in a water ‘gain’. This is not specific for drip irrigation – the promise of water ‘gains’ is also present in other irrigation technologies and modernization projects. For example, previous modernization projects in the Ain Bittit irrigation system, of which the Seguia Khrichfa is a secondary canal, focused on lining of the infrastructure in order to re-allocate the ‘saved’ water for drinking water to the city of Meknes. All modernization projects in Ain Bittit have been preceded or accompanied by a process of re-allocating yet-to-be saved water. For example, the many actors involved in the conversion to drip irrigation all claim that the water ‘gain’ would be theirs. As this is never openly discussed, it is only when projects are implemented that competition over the ‘saved’ water arises. Yet, this competition is not brought to the open and each actor claims the ‘saved’ water, resulting on multiple claims on the yet-to-be saved water. Within the irrigation system, the ‘saved’ water mixes with the rest of the flows in the basin. This makes it 1) impossible to know how much water is actually saved, and thus how much water could be re-distributed, and 2) invisible to others who actually uses the ‘saved’ water. Only silent actors in a powerless position – like the aquifer – lose out. Chapter 3 concludes with the suggestion that not measuring actual water gains is strategic because it de-politicises re-allocations, allowing several actors to appropriate the yet-to-be-saved water without confrontations.

    Chapter 4 describes the performance of technology as co-defining the water distribution in an irrigation system, and its role in defining possible solutions. The technology has a function in co-shaping institutions, which forms also depend on the distributional questions that institutions aim to tackle. For drip irrigation, this means that the introduction of drip irrigation technology is shaped through and also provokes distributional questions. Which water users are in- or excluded from the system? What are legitimate reasons for accessing water? The introduction of drip irrigation brings with it discourses on efficiency, productivity and avoidance of waste – which shape the framing of distributional questions. Surprisingly, these questions do not lead to open conflicts in Khrichfa. The conclusions of Chapter 4 suggest that this is because technologies can play a role in de-politicizing change. Suggesting new technologies or drawing old technologies into new configurations allows actors to enforce changes in the irrigation system without anyone losing face. When difficult questions on in-or exclusion are defined as issues of efficiency and modernization – and thus as progress and the way forward – these are hard to openly oppose.

    Chapter 5 explores socio-technical performances of drip irrigation in the Seguia Khrichfa area by approaching performance as emerging from practice. The positivity of drip irrigation (constructed through efficiency experiments in laboratories which travelled to agricultural policies and donor-led debates) radiates on drip irrigation users and the administration and works in the field to create identities and form alliances. In Khrichfa, drip irrigation contributes to a shift towards modern, entrepreneurial and clean agriculture, and strengthens the ties between the irrigation community and the State. These are performances of drip irrigation that come into being in wider networks in which the technology interacts. In other situations (at other moments, in interaction with other actors, another environment) drip irrigation could perform in different ways. In the most extreme cases, drip irrigation does not even have to be in place physically as an object to perform. Talking about drip irrigation, aligning with drip irrigation and its discourses of efficiency and modernity also performs. Yet, the socio-technical focus on processes of network ordering hints at the fragility of the performances of drip irrigation: actors need to actively keep the network they constructed in place to maintain identities and alliances. This understanding of performance also means that drip irrigation can perform in many ways, but this does not mean that these performances can be expected in other contexts. Likewise, one cannot expect that drip irrigation is always efficient. Drip irrigation only becomes efficient through practice, when actors, technology and the environment all work towards the goal of using water efficiently.

    The general discussion concludes by answering the main research question on how drip irrigation performs. Drip irrigation performs as an efficient technology, which is often translated in irrigation policies as needing less water while increasing productivities. The suggestion that water is ‘saved’ that would otherwise be ‘lost’ creates a promise of water gains which can be re-distributed. Drip irrigation also performs as network builder and creator of identities. Both modern drip irrigation and notions of performance (such as efficiency) are strategic for de-politicizing re-allocation issues. Changing water allocations via efficiency arguments or transforming institutions via technologies is attractive as it silences opposition. This thesis also highlights how performance assessments – for example based on irrigation efficiency – perform (and are performed); they re-order the relations and interactions between people and objects. Likewise, FMIS, as a category to define irrigation systems perform. Any definition or categorisation implies certain possibilities or restrictions, and the water users of the Seguia Khrichfa know well how to use these in their favour. As implications of this research for the Moroccan agricultural policy, this study suggests that it is doubtful whether drip irrigation makes available the anticipated water, as the Moroccan government is not the only actor that claims access to the ‘saved’ water. Yet, this thesis suggests that drip irrigation does help farming communities to experience that they ‘count’ in modern agriculture – though other cheaper ways of attaining this could be possible. In addition, the suggestion is made to more explicitly measure multiple performances – to celebrate their differences rather than creating a suggestion of unity. Being open to the multiple performances of drip irrigation will help to explain for whom drip irrigation works and how, and at the costs of what. The thesis concludes with a personal reflection that drip irrigation and FMIS can very well go together, at the condition that both are re-conceptualized.

    Low cost drip irrigation in Burkina Faso : unravelling actors, networks and practices
    Wanvoeke, M.J.V. - \ 2015
    Wageningen University. Promotor(en): Margreet Zwarteveen; Charlotte de Fraiture, co-promotor(en): J.P. Venot. - Wageningen University : Wageningen - ISBN 9789462576117 - 144
    irrigatie - irrigatiesystemen - kosten - waterbeheer - waterbeleid - druppelbevloeiing - burkina faso - irrigation - irrigation systems - costs - water management - water policy - trickle irrigation - burkina faso

    Title: Low cost drip irrigation in Burkina Faso: Unravelling Actors, Networks and Practices

    In Burkina Faso, there is a lot of enthusiasm about Low Cost Drip Irrigation (LCDI) as a tool to irrigate vegetables, and thus improve food security, solve water scarcity and reduce poverty. Already for more than ten years, development cooperation donors, policy makers, and kit designers have invested in the technology, funded its dissemination, and encouraged farmers to adopt it. Yet, there are only very few farmers who are using the technology in their fields. This study shows that this is because the funds for paying the technology mostly do not come from them, but from external donors. For LCDI promoters and disseminators, LCDI is also importantly a tool to survive or make profits. For this, they need to continuously re-assert the success of the technology through reports and stories. Farmers agree to play this game, as they hope and do receive other benefits by associating themselves with LCDI projects.

    Problemen met verdeling meststoffen en middelen moet je voorkomen
    Velden, P. van; Blok, C. - \ 2015
    Onder Glas 12 (2015)5. - p. 28 - 29.
    glastuinbouw - kleinfruit - aardbeien - waterverdelingssystemen - watervoorziening - druppelbevloeiing - mengmeststoffen - modellen - controle - greenhouse horticulture - small fruits - strawberries - water distribution systems - water supply - trickle irrigation - compound fertilizers - models - control
    Gericht water geven is sterk afhankelijk van de mogelijkheden op je bedrijf. Wanneer het tegen zit stapelen wel zes gietbeurten zich op in de druppelslang. Dat gebeurt zowel in grote als in kleine systemen, toonde Chris Blok aan. Met de aanleg van een nieuw watergeefsysteem kun je daar al rekening mee houden.
    Smart irrigation based on soil indicators for moisture, EC and temperature
    Balendonck, Jos - \ 2015
    irrigation - salinity - temperature - relative humidity - outturn - trickle irrigation - turkey - recirculating systems
    Waterefficiënte Emissieloze Kas : optimaal telen
    Beerling, E.A.M. ; Blok, C. ; Os, E.A. van; Ruijven, J.P.M. van - \ 2015
    glastuinbouw - emissiereductie - emissie - bemesting - druppelbevloeiing - steenwol - substraten - recirculatiesystemen - filtratie - greenhouse horticulture - emission reduction - emission - fertilizer application - trickle irrigation - rockwool - substrates - recirculating systems - filtration
    Aanpassen recept van bemesting bij emissieloos telen per element. Interval tussen analyses zo kort mogelijk houden.
    Water management in greenhouse horticulture
    Voogt, Wim - \ 2014
    greenhouse horticulture - cropping systems - drainage - rockwool - substrates - soilless culture - moisture meters - trickle irrigation - water harvesting - water quality - emission - fertilizer application
    Ontwikkeling van veilige toepassingen voor gewasbehandelingen met electrolysewater in de glastuinbouw
    Hofland-Zijlstra, J.D. ; Vries, R.S.M. de; Blok, C. ; Boer-Tersteeg, P.M. de; IJdo, M.L. ; Bosch, C. ; Ayik, A. ; Bruning, H. - \ 2013
    Bleiswijk : Wageningen UR Glastuinbouw (Rapporten WUR GTB 1240) - 50
    water - elektrolyse - glastuinbouw - gewasbescherming - milieubescherming - arbeidsomstandigheden - plantenvoeding - biociden - ultrasone behandeling - verneveling - druppelbevloeiing - nederland - water - electrolysis - greenhouse horticulture - plant protection - environmental protection - working conditions - plant nutrition - biocides - ultrasonic treatment - nebulization - trickle irrigation - netherlands
    Dit onderzoek had als doel om de werking van electrolysewater te verbinden met de chemische eigenschappen en op zoek te gaan naar veilige toepassingen als gewasbehandeling voor de glastuinbouwsector. Vijf producenten hebben voor dit onderzoek de gewenste samenstelling van electrolysewater aangeleverd. Alle producten met daarin 36-65 ppm vrij chloor waren binnen vijf minuten 100% effectief tegen de bacterie, Erwinia chrysanthemi en de schimmel, Botrytis cinerea. De grenzen van gewasschade in de kiemplantentest werden sterker bepaald door de hoeveelheid natriumzout en EC gehalte van de electrolysevloeistof dan de hoeveelheid vrij chloor. In een korte meedruppelproef met tomaat zijn verschillende concentraties vrij chloor (0, 4, 8, 20 ppm) gedoseerd aan het voedingswater. Er werd geen gewasschade gevonden of negatief effect op de wortelkolonisatie van Trianum door de geringe chloorwaardes (vrij en totaal) die na vier weken bij de druppelaar werden teruggemeten. Testen met gewasbehandelingen laten zien dat éénmalige behandelingen tot 300 ppm geen gewasschade geven. Bij meerdere toepassingen is groeiremming te voorkomen door lagere concentraties te gebruiken of blootstellingstijd te beperken. Electrolysewater kan een veilig en bruikbaar alternatief bij het terugdringen van het fungicidegebruik.
    Teelt de grond uit geeft kwekers nieuwe inzichten (interview met Casper Slootweg)
    Haverman, K. ; Slootweg, G. - \ 2013
    De Boomkwekerij 25 (2013)10. - ISSN 0923-2443 - p. 14 - 15.
    overblijvende planten - cultuurmethoden - zandgronden - drainage - bemesting - fertigatie - druppelbevloeiing - bereikt resultaat - projecten - perennials - cultural methods - sandy soils - drainage - fertilizer application - fertigation - trickle irrigation - achievement - projects
    Het project Teelt de grond uit laat zien dat er een goede kwaliteit vasteplanten kan worden gekweekt op zandbedden. De meest waardevolle informatie zit volgens kweker Remy Lubbe van Molter echter in de nieuwe inzichten over bemesting. "Wij gaan volgend jaar ook in de reguliere teelt ander bemesten dan we tot op heden hebben gedaan", vertelt de kweker.
    Controlling plant balance by irrigation
    Nederhoff, E.M. ; Houter, G. - \ 2009
    Practical Hydroponics & Greenhouses 2009 (2009)105. - ISSN 1321-8727 - p. 45 - 50.
    tuinbouw - kassen - groeimedia - tomaten - druppelbevloeiing - irrigatie - substraten - glastuinbouw - horticulture - greenhouses - growing media - tomatoes - trickle irrigation - irrigation - substrates - greenhouse horticulture
    Fertigatie prei nog in kinderschoenen
    Geel, W.C.A. van; Haan, J.J. de - \ 2008
    Groenten en Fruit. Algemeen 2008 (2008)30. - ISSN 0925-9694 - p. 32 - 33.
    preien - allium porrum - uitspoelen - fertigatie - kunstmeststoffen - druppelbevloeiing - vollegrondsgroenten - vollegrondsteelt - leeks - allium porrum - leaching - fertigation - fertilizers - trickle irrigation - field vegetables - outdoor cropping
    Kennisinstelling PPO zoekt mogelijkheden om stikstof in prei efficiënter te benutten en minder nitraat te laten uitspoelen, zonder verlies van productie en van kwaliteit. Fertigatie, al dan niet in combinatie met foliebedekking, is zo'n mogelijkheid. De ervaringen van PPO Vredepeel vanaf 2006 worden in dit artikel beschreven
    Weeggoot kan watergift optimaliseren
    Baltissen, A.H.M.C. ; Dalfsen, P. van - \ 2008
    De Boomkwekerij 2008 (2008)21. - ISSN 0923-2443 - p. 8 - 9.
    boomkwekerijen - potplanten - containerplanten - meetinstrumenten - groeimedia - vochtgehalte - druppelbevloeiing - irrigatie - forest nurseries - pot plants - container grown plants - indicating instruments - growing media - moisture content - trickle irrigation - irrigation
    De weeggoot is sinds 2007 uitvoerig in onderzoek, bij PPO en bij verschillende kwekers, de ervaringen met het optimaliseren van de watergift zijn positief.
    Wankel succes met druppelfertigatie in Franse prei : Op Proefboerderij Vredepeel
    Verstegen, S. ; PPO Akkerbouw, Groene Ruimte en Vollegrondsgroente, - \ 2007
    Groenten en Fruit. Algemeen 2007 (2007)40. - ISSN 0925-9694 - p. 76 - 77.
    allium porrum - preien - cultuurmethoden - fertigatie - druppelbevloeiing - toedieningswijzen - gewasopbrengst - vloeibare kunstmeststoffen - uitspoelen - waterbeheer - milieueffect - frankrijk - allium porrum - leeks - cultural methods - fertigation - trickle irrigation - application methods - crop yield - liquid fertilizers - leaching - water management - environmental impact - france
    Bij PPO Vredepeel wordt in proeven prei geteeld met behulp van druppelfertigatie, met minder kunstmest en minder uitspoeling als doelen. In Frankrijk werken al sinds 2005 vijf preitelers in de streek Loire-Atlantique er mee op hun hele areaal. Eén van hen gebruikt 20 tot 40 procent minder kunst mest dan voorheen
    Slijm, vuil en giftige stoffen (interview met o.a. Wim Voogt)
    Boonekamp, G. ; Voogt, W. - \ 2007
    Vakblad voor de Bloemisterij 62 (2007)49. - ISSN 0042-2223 - p. 40 - 41.
    irrigatie - druppelbevloeiing - anaërobe micro-organismen - irrigatiewater - verontreiniging - doorspoelen - glastuinbouw - irrigation - trickle irrigation - anaerobes - irrigation water - pollution - flushing - greenhouse horticulture
    In rijk bemest gietwater zonder zuurstof voelen schadelijke bacteriën zich prima thuis. Het resultaat is verstopping van het watergeefsysteem en gifstoffen voor de plant. Geregeld doorspoelen en het water verversen kan de problemen oplossen
    Belang van zuurstofrijk druppelwater ter discussie (interview met o.a. Wim Voogt)
    Boonekamp, G. ; Voogt, W. - \ 2007
    Vakblad voor de Bloemisterij 62 (2007)49. - ISSN 0042-2223 - p. 38 - `39.
    wortels - substraten - irrigatiewater - druppelbevloeiing - irrigatiesystemen - zuurstof - roots - substrates - irrigation water - trickle irrigation - irrigation systems - oxygen
    Wortels krijgen genoeg zuurstof als ze in goed, luchtig substraat staan en de juiste watergeefstrategie wordt gehanteerd. Dat is de meest gangbare mening. Onderzoekers twisten over het nut van zuurstofrijk water toevoegen om het zuurstofgehalte in het substraat te verhogen.
    Dood water zorgt voor problemen (interview met o.a. Wim Voogt)
    Boonekamp, G. ; Voogt, W. - \ 2007
    Groenten en Fruit. Algemeen 2007 (2007)48. - ISSN 0925-9694 - p. 18 - 19.
    druppelbevloeiing - anaërobe micro-organismen - irrigatiesystemen - irrigatiewater - verontreiniging - doorspoelen - trickle irrigation - anaerobes - irrigation systems - irrigation water - pollution - flushing
    Als voedingswater zuurstofarm ofwel 'dood' is, worden anaerobe micro-organismen zeer actief. Dat kan leiden tot slijmvorming, vervuiling van het druppelsysteem en de vorming van voor de plant giftige omzettingsproducten. Dit lijkt op te lossen door zuurstofrijk druppelwater te geven en het systeem regelmatig door te spoelen
    Perspectief druppelirrigatie en -fertigatie in consumptieaardappelen op droge zandgrond valt tegen
    Geel, W.C.A. van - \ 2004 2004 (2004)15 jan..
    aardappelen - solanum tuberosum - stikstofmeststoffen - stikstof - druppelbevloeiing - toedieningswijzen - zandgronden - bodemtypen (naar textuur) - proeven op proefstations - bemesting - akkerbouw - potatoes - nitrogen fertilizers - nitrogen - trickle irrigation - application methods - sandy soils - soil types (textural) - station tests - fertilizer application - arable farming
    De toediening van stikstof en water via druppelslangen werd enkele jaren geleden beschouwd als één van de mogelijke oplossingen voor het verkleinen van het stikstofoverschot op droge zandgronden. PPO heeft deze methode onderzocht in de teelt van consumptieaardappelen, maar het perspectief ervan viel tegen
    Druppelirrigatie met brak water voor schurftbestrijding in pootaardappelen
    Alblas, J. ; Floot, H. - \ 2002
    Lelystad : Praktijkonderzoek Plant en Omgeving (Project-rapporten 2002) - 45 p.
    irrigatie - druppelbevloeiing - pootaardappelen - zout water - brakwater - gewasopbrengst - bodemstructuur - zware kleigronden - streptomyces scabiei - nederland - irrigation - trickle irrigation - seed potatoes - saline water - brackish water - crop yield - soil structure - clay soils - streptomyces scabiei - netherlands
    Druppelirrigatie en fertigatie in Bintje consumptie-aardappelen
    Paauw, J. - \ 2001
    PPO-bulletin akkerbouw 5 (2001)1. - ISSN 1385-5301 - p. 5 - 6.
    plantenvoeding - aardappelen - mestgiften - stikstof - toedieningshoeveelheden - fertigatie - irrigatie - druppelbevloeiing - irrigatiesystemen - beregening - opbrengsten - gewasopbrengst - gewaskwaliteit - kwaliteit - kosten-batenanalyse - kosten - bemesting - plant nutrition - potatoes - dressings - nitrogen - application rates - fertigation - irrigation - trickle irrigation - irrigation systems - overhead irrigation - yields - crop yield - crop quality - quality - cost benefit analysis - costs - fertilizer application
    In proeven bij PPO Lelystad (1998-2000) werd het effect onderzocht van verschillende methoden van toediening van vocht en stikstof (druppelirrigatie en fertigatie m.b.v. druppelslangen boven in de rug; beregening), bij verschillende stikstofgiften, op de opbrengst en kwaliteit (onderwatergewicht; grofheid knollen) van Bintje consumptieaardappelen. De kosten van druppelslangen blijken niet terugverdiend te worden
    Drastische Dränabschwächung; Im Substratverfahren bald möglich?
    Heuvelink, E. ; Stanghellini, C. - \ 2001
    TASPO Gartenbaumagazin 9 (2001). - p. 30 - 32.
    capsicum annuum - groeimedia - steenwol - drainage - plantenvoeding - elektrische geleiding - opbrengsten - watervoorziening - dosering - druppelbevloeiing - paprika - glastuinbouw - growing media - rockwool - plant nutrition - electrical conductance - yields - water supply - dosage - trickle irrigation - sweet peppers - greenhouse horticulture
    Teelt van paprika zonder drainagesysteem: verslag van het onderzoek naar het verloop van het watergehalte, EC en productie in steenwol bij conventionele teeltomstandigheden (80 procent water met drainagesysteem) en zonder drainagesysteem (50 procent water in het substraat). In het laaltste geval vindt de watervoorziening plaats middels druppelirrigatie
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