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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    On the role of soil organic matter for crop production in European arable farming
    Hijbeek, Renske - \ 2017
    Wageningen University. Promotor(en): M.K. van Ittersum, co-promotor(en): H.F.M. ten Berge. - Wageningen : Wageningen University - ISBN 9789463436632 - 211
    soil fertility - soil fertility management - soil management - soil conservation - organic matter - soil organic matter - nitrogen - nitrogen fertilizers - green manures - manures - straw - soil carbon sequestration - cover crops - crop yield - yields - meta-analysis - food security - europe - drivers - barriers - bodemvruchtbaarheid - bodemvruchtbaarheidsbeheer - bodembeheer - bodembescherming - organische stof - organisch bodemmateriaal - stikstof - stikstofmeststoffen - groenbemesters - mest - stro - koolstofvastlegging in de bodem - dekgewassen - gewasopbrengst - opbrengsten - meta-analyse - voedselzekerheid - europa - chauffeurs - barrières

    The aim of this thesis was to improve understanding of the role of organic inputs and soil organic matter (SOM) for crop production in contemporary arable farming in Europe. For this purpose, long-term experiments were analysed on the additional yield effect of organic inputs and savings in mineral fertiliser. In addition, a farm survey was conducted to find drivers and barriers for the use of organic inputs and to assess if arable farmers in Europe perceive a deficiency of SOM.

    The findings in this thesis suggest that at least on the shorter term, on average, there seems to be no immediate threat from a deficiency of SOM to crop production in arable farming in Europe. The long-term experiments showed that with sufficient use of only mineral fertilisers, on average, similar yields could be attained over multiple years as with the combined use of organic inputs and mineral fertiliser. This was reflected in the farm survey, in which a large majority of farmers indicated not to perceive a deficiency of SOM. Analysis of long-term experiments also showed that more mineral fertiliser N was saved when using farmyard manure at high N rates (with mineral fertiliser application) than at low N rates (without mineral fertiliser application), based on comparisons at equal yield.

    Specific crops and environments did benefit from organic inputs and more SOM in terms of crop production. Long-term experiments showed that organic inputs give benefit to crop production in wet climates and on sandy soils. In addition, farmers perceived a higher deficiency of SOM on steep slopes, sandy soils, wet and very dry climates. The additional yield effect of organic inputs was significant for potatoes. More in general, farmers who cultivated larger shares of their land with specialized crops (including potatoes, sugar beets, onions and other vegetables) than cereals perceived a higher deficiency of SOM. It seems that while the functions of SOM can be replaced with technical means to a large extent (e.g. tillage, use of mineral fertilisers), there are limits to this technical potential when environmental conditions are more extreme and crops are more demanding.

    The farm survey revealed that farmers perceive a trade-off between improved soil quality on the one hand and increased pressures from weeds, pests and diseases and financial consequences on the other hand when using organic inputs. If policies aim to stimulate the maintenance or increase of SOM, more insight is needed into the conditions that regulate the pressures of weeds, pests and diseases in response to organic inputs. Financial consequences (at least on the short term) should also be accounted for. More importantly however, benefits from SOM for crop production cannot be taken for granted. Only in specific situations such benefits will exist. If European policies on SOM aim to include benefits for crop production, focus should be on areas with more extreme environmental conditions (very dry or wet climates, steep slopes, sandy soils), or cropping systems with more specialized or horticultural crops rather than cereals.

    Beoordeling van mogelijk gebruik van N-bijmestsystemen voor aardappelen als equivalente maatregel
    Ruijter, F.J. de; Schröder, J.J. ; Geel, W.C.A. van; Postma, R. - \ 2016
    Wageningen : Wageningen Plant Research (Wageningen Plant Research rapport 672) - 37
    solanum tuberosum - aardappelen - akkerbouw - bemesting - maatregelen - stikstofmeststoffen - nederland - solanum tuberosum - potatoes - arable farming - fertilizer application - measures - nitrogen fertilizers - netherlands
    Het vijfde Nederlandse Actieprogramma Nitraatrichtlijn biedt ruimte voor zgn. equivalente maatregelen: maatregelen waarbij gebruiksnormen verhoogd kunnen worden zonder dat de milieukwaliteit verslechtert. Dit onderzoek richt zich op evaluatie van N-bijmestsystemen voor aardappel en gebruik als equivalente maatregel. Een theoretische verkenning laat zien dat ideale N-bijmestsystemen die voor verschillende groeiomstandigheden de juiste N-gift geven een iets lager N-overschot geven ten opzichte van bemesting volgens een vaste totale gift. Evaluatie van proeven liet zien dat N-bijmestsystemen mogelijke besparingen ten opzichte van de N-bemestingsrichtlijn veelal goed konden aangeven, maar situaties met een hogere optimale N-gift niet. Daarmee heeft gebruik van N-bijmestsystemen als equivalente maatregel momenteel onvoldoende perspectief.
    Development of a breeding strategy for nitrogen use efficiency in spinach (Spinacia oleracea L.)
    Chan Navarrete, J.R. - \ 2016
    Wageningen University. Promotor(en): Edith Lammerts van Bueren, co-promotor(en): Oene Dolstra; Gerard van der Linden. - Wageningen : Wageningen University - ISBN 9789462577961 - 161
    spinacia oleracea - spinach - plant breeding - nitrogen - nutrient use efficiency - genetic mapping - nitrogen fertilizers - fertilizer application - genetic diversity - nitrogen response - spinacia oleracea - spinazie - plantenveredeling - stikstof - nutriëntengebruiksefficiëntie - genetische kartering - stikstofmeststoffen - bemesting - genetische diversiteit - stikstofrespons

    Spinach (Spinacia oleracea L.) is one of the most consumed leafy vegetables worldwide and it is considered to be highly nutritious. Spinach is a short-cycle leafy crop that has a high demand for nitrogen in order to rapidly come to a harvestable product that has the required dark green colour within a reasonable harvest window. In commercial production of spinach the recovery of N is poor, which may result in environmental pollution. To increase sustainability of both organic and conventional spinach cultivation there is a need to reduce the dependency on high levels of nitrogen. Growers therefore urgently need cultivars with a satisfactory yield under reduced N input conditions. Nitrogen use efficiency (NUE), defined as the ability to produce high biomass per unit N applied, is low in spinach. The present study aims to evaluate spinach genotypes for selectable traits under varying N supply and provide tools and knowledge to facilitate the development of varieties with good yield, quality and stability under low N input. To minimise environmental variation affecting the identification of traits related to NUE a screening method was developed using a hydroponics system. The genetic diversity for NUE related traits was first studied with 24 commercial cultivars under contrasting levels of N supply based on the Ingestad model with a steady-state N application. This demonstrated that the hydroponics screening strategy as a pre-screening tool enabled reliable detection of heritable variation among cultivars for NUE-related traits under optimal as well as suboptimal N input. Shoot dry weight and leaf area were preferred selectable traits for the detection of heritable differences contributing to NUE in spinach. The effect of N application strategy was examined in seven cultivars grown under hydroponics conditions with low and high N levels supplied either as a single bulk N application resembling N fertilization in field cultivation, or a steady-state N application according to Ingestad. The latter application strategy provided more stable and reproducible conditions for determination of genetic differences in NUE under low N conditions for a short-cycle leafy vegetable crop. Several tools for molecular genetic evaluation of NUE in spinach were provided as well, including a SNP marker set for marker-assisted breeding, a genetic mapping population with a corresponding genetic map, and the identification of two major QTL regions contributing to growth under low N conditions. With these tools, an efficient strategy for breeding for NUE efficiency in spinach would include screening under controlled conditions at high and low N using leaf area, biomass and root to shoot ratio as selectable traits, and QTL identification of genetic factors that can be targeted and combined using marker-assisted selection. An in depth genotype by environment interaction analysis using six field trials showed that environmental factors like temperature, soil, and management strongly influence nitrogen availability in the soil in a short cycle crop like spinach. This severely complicates selection and breeding for NUE of spinach under field conditions, and emphasizes the importance of performing trials under better controllable conditions for genetic dissection of NUE and discovery of genetic factors contributing to NUE. It also underscores the importance of validating these findings in various field trials. Multi-environment field trials with different levels of N fertilization will then allow selection of cultivars that combine stable performance under various low input growing conditions with high yields under more favorable conditions.

    Relatie tussen stikstofbodemoverschot en waterkwaliteit
    Hooijboer, A. ; Oenema, J. ; Doornewaard, G.J. - \ 2015
    Nieuwsbrief Koeien & Kansen (2015)43. - p. 2 - 2.
    nitraatuitspoeling - stikstofmeststoffen - waterkwaliteit - grondwater - bemesting - mestoverschotten - uitspoelen - nitrate leaching - nitrogen fertilizers - water quality - groundwater - fertilizer application - manure surpluses - leaching
    Minder uitspoeling van nitraat naar het grondwater is een doel van het mestbeleid. Bij efficiëntere stikstofbemesting zou het overschot aan stikstof in de bodem moeten dalen. Daarmee zou je verwachten dat ook de nitraatconcentratie in het grondwater vermindert. Maar is dat ook zo?
    Mineral nutrition of cocoa : a review
    Vliet, J.A. van; Slingerland, M.A. ; Giller, K.E. - \ 2015
    Wageningen : Wageningen UR - ISBN 9789462577053 - 57
    cacao - mineralenvoeding - bevruchting - kunstmeststoffen - mestbehoeftebepaling - vruchtbaarheid - voedingsstoffenbehoeften - voedingsstoffenbeschikbaarheid - grondanalyse - voedingsstoffentekorten - kaliummeststoffen - stikstofmeststoffen - fosformeststoffen - agrarische productiesystemen - overzichten - cocoa - mineral nutrition - fertilization - fertilizers - fertilizer requirement determination - fertility - nutrient requirements - nutrient availability - soil analysis - nutrient deficiencies - potassium fertilizers - nitrogen fertilizers - phosphorus fertilizers - agricultural production systems - reviews
    This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?
    Extra ruimte kunstmest-stikstof in pilot goed benut
    Verloop, J. ; Hilhorst, G.J. - \ 2015
    Nieuwsbrief Koeien & Kansen (2015)41. - p. 3 - 3.
    melkveehouderij - kunstmeststoffen - stikstofmeststoffen - normen - bemesting - dairy farming - fertilizers - nitrogen fertilizers - standards - fertilizer application
    Zes melkveebedrijven kregen voor onderzoek in 2014 de ruimte om meer kunstmest-N op hun bedrijf te gebruiken dan de generieke gebruiksnormen.
    Pilot bedrijfsspecifieke stikstofbemesting met drijfmest
    Aarts, H.F.M. ; Schroder, J.J. - \ 2015
    Nieuwsbrief Koeien & Kansen (2015)42. - p. 1 - 1.
    bemesting - mestbeleid - mestgiften - drijfmest - stikstofmeststoffen - normen - milieueffect - gewasopbrengst - melkveehouderij - fertilizer application - manure policy - dressings - slurries - nitrogen fertilizers - standards - environmental impact - crop yield - dairy farming
    Bemestingsnormen moeten voorkomen dat meststoffen het grond- en oppervlaktewater te zwaar belasten. Voor het verkennen van de hoogte ervan is door de Werkgroep Onderbouwing Gebruiksnormen een protocol ontwikkeld. Met kennis van de gewasopbrengst en de efficiëntie waarmee meststoffen door het gewas worden opgenomen, kan worden bepaald welke mestgiften milieukundig verantwoord zijn.
    Optimalisatie N-bemesting soja
    Timmer, R.D. ; Visser, C.L.M. de - \ 2014
    Lelystad : PPO AGV - 15
    akkerbouw - sojabonen - peulvruchten - veevoeding - bemesting - stikstofmeststoffen - opbrengst - duurzaamheid (sustainability) - rhizobium - arable farming - soyabeans - grain legumes - livestock feeding - fertilizer application - nitrogen fertilizers - outturn - sustainability - rhizobium
    Soja is weliswaar een vlinderbloemig gewas dat (via de vorming van stikstofknolletjes aan de wortels) in z’n eigen stikstofbehoefte kan voorzien, de ervaring leert echter dat het gewas in Nederland vaak een erg lichte bladkleur heeft gedurende het seizoen wat kan duiden op N-gebrek. Voor de vorming van de stikstofknolletjes aan de wortels is een goed geslaagde enting nodig met Rhizobium bacteriën. Over hoeveel knolletjes er per plant nodig zijn om in de N-behoefte te kunnen voorzien bestaat nog grote onduidelijkheid. Ook is niet duidelijk of een N-bemesting bij soja kan leiden tot hogere en stabielere opbrengsten.
    Recirculatie potorchidee 10. Scenarioberekeningen stikstof emissie - 1
    Os, E.A. van; Kromwijk, J.A.M. - \ 2014
    sierplanten - potplanten - orchideeën als sierplanten - bemesting - vloeibare kunstmeststoffen - recirculatiesystemen - glastuinbouw - stikstofbalans - stikstofmeststoffen - ornamental plants - pot plants - ornamental orchids - fertilizer application - liquid fertilizers - recirculating systems - greenhouse horticulture - nitrogen balance - nitrogen fertilizers
    Voor andere gewassen zijn rekenprogramma’s ontwikkeld om effecten van bv. het natriumgehalte in het water en de natrium grenswaarde op de stikstof emissie door te rekenen. Met behulp van zo’n waterstromen model zijn verschillende scenario’s doorgerekend om inzicht te geven in het effect op de stikstof emissie bij recirculatie in de teelt van potorchideeën.
    N-gift groenbemester in de knel
    Houweling, P. van; Haan, J.J. de - \ 2014
    Akker magazine 10 (2014)10. - ISSN 1875-9688 - p. 19 - 19.
    akkerbouw - bemesting - groenbemesters - zandgronden - lössgronden - stikstofmeststoffen - uitspoelen - arable farming - fertilizer application - green manures - sandy soils - loess soils - nitrogen fertilizers - leaching
    De stikstofbemesting van groenbemesters dreigt volgend jaar flink in de verdrukking te komen. De norm voor uitspoelingsgevoelige gewassen voor zand en lössgronden in Brabant en Limburg daalt met 20 procent. Hierdoor zullen steeds meer telers de stikstof die toegestaan is voor de groenbemester geven aan het hoofdgewas. Interview met onderzoeker Janjo de Haan van PPO-agv in Lelystad
    Stikstofwerking van mineralenconcentraten op grasland = N fertilizer replacement value of mineral concentrates on grassland /
    Holshof, G. ; Middelkoop, J.C. van - \ 2014
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 769) - 42
    stikstof - mineralen - graslanden - stikstofmeststoffen - bemesting - mestverwerking - dierlijke meststoffen - nitrogen - minerals - grasslands - nitrogen fertilizers - fertilizer application - manure treatment - animal manures
    In 2009–2012 field experiments on grassland took place to determine the N fertilizer replacement value of mineral concentrates.
    Nieuwe bijmestsystemen en -strategieën voor aardappel op zand- en lössgrond. Deel 2: resultaten veldproeven 2012 en 2013
    Geel, W.C.A. van; Kroonen-Backbier, B.M.A. ; Schans, D.A. van der; Malda, J.T. - \ 2014
    Lelystad : PPO AGV - 66
    akkerbouw - veldgewassen - aardappelen - precisielandbouw - bemesting - stikstofmeststoffen - sensors - gewasdichtheid - arable farming - field crops - potatoes - precision agriculture - fertilizer application - nitrogen fertilizers - sensors - crop density
    Nieuwe dan wel verbeterde N-bijmeststrategieën op basis van gewassensing en een plan van aanpak om deze strategieën te testen.
    Gebruiksnorm brouwgerst hoger
    Timmer, R.D. - \ 2014
    Boerderij 99 (2014)39. - ISSN 0006-5617 - p. 32 - 32.
    akkerbouw - gerst - veldproeven - brouwgranen - bemesting - stikstofmeststoffen - rassen (planten) - eiwitgehalte - normen - opbrengst - proeven op proefstations - arable farming - barley - field tests - brewers' grains - fertilizer application - nitrogen fertilizers - varieties - protein content - standards - outturn - station tests
    80 Kilo stikstof per hectare is eigenlijk te weinig om kwalitatief goede brouwgerst te telen. Ruud Timmer van het PPO te Lelystad en brouwers pleiten voor een hogere gebruiksnorm. Onderzoek naar rassen voor de mouterijen is gewenst.
    Effect bemesting op ziekteontwikkeling in stamslabonen industrieteelt
    Evenhuis, B. ; Verstegen, H.A.G. ; Wilms, J.A.M. ; Topper, C.G. - \ 2014
    Wageningen : PPO AGV - 22
    groenteteelt - veldgewassen - phaseolus vulgaris - peulvruchten (groente) - industriële gewassen - bemesting - stikstofmeststoffen - overbemesting - oogstverliezen - opbrengst - relatie tussen groei en oogst - ziektebestrijdende teeltmaatregelen - schimmelziekten - sclerotinia - botrytis - gewasbescherming - vegetable growing - field crops - phaseolus vulgaris - vegetable legumes - industrial crops - fertilizer application - nitrogen fertilizers - top dressings - yield losses - outturn - growth yield relationship - cultural control - fungal diseases - sclerotinia - botrytis - plant protection
    In de teelt van stamslabonen voor de industrie worden vaak problemen ondervonden met ziektes zoals Sclerotinia en Botrytis. Deze ziektes worden geassocieerd met (over)bemesting. De gebruiksnorm voor stikstofgift was in 2012 en 2013, 110 kg N/ha respectievelijk 120 kg N/ha, op zand- en kleigrond. Werd er niet bemest dan leidde dit tot een significante opbrengstverlaging. Een overbemesting tot 150% van de gebruiksnorm na aftrek van N-min gaf eveneens een opbrengstverlaging te zien. Bemesting trappen variërend van 50 tot 125% van de normbemesting lieten geen significant verschil in opbrengst zien. Een evenwichtig teeltadvies waarbij het bemestingsniveau maximaal bijdraagt aan plantweerstand en productkwaliteit is belangrijk.
    Steeds preciezer met de sensor
    Houweling, P. van; PPO Akkerbouw, Groene Ruimte en Vollegrondsgroente, - \ 2014
    Akker magazine 10 (2014)4. - ISSN 1875-9688 - p. 18 - 21.
    akkerbouw - aardappelen - loofvernietiging - sensors - bemesting - stikstofmeststoffen - gerst - spuitapparaten - pleksgewijs spuiten - bladbespuiting - precisielandbouw - arable farming - potatoes - haulm destruction - sensors - fertilizer application - nitrogen fertilizers - barley - sprayers - spot spraying - foliar spraying - precision agriculture
    Maurits Bax uit Luyksgestel werkt met de Yara N-sensor. Zo spuit hij minder dan een derde van de voorgeschreven dosering voor loofdodingsmiddel in aardappelen. Andere toepassingen zijn minder praktijkrijp, zoals aardappelen bijmesten. Daarvoor lijkt een app, ontwikkeld door het PPO, uitkomst te gaan bieden. PPO Lelystad begeleidt het project waar Bax aan mee doet. De teler kreeg de afgelopen twee teeltseizoenen voor zijn aardappelen een adviesgift van PPO op basis van twee systemen: de BemestingsNavigator aardappel van Altic en een systeem dat PPO ontwikkelt. De volgende toepassing was voor het spuiten van halmverstevigers in zomergerst.
    Nutrient use efficiency in the food chain of China
    Ma, L. - \ 2014
    Wageningen University. Promotor(en): Oene Oenema, co-promotor(en): Gerard Velthof; F. Zhang. - Wageningen : Wageningen University - ISBN 9789461738448 - 193
    stikstofmeststoffen - fosformeststoffen - voedselketens - voedselzekerheid - kosten voor voedsel - milieueffect - nutrientenbeheer - kringlopen - nutriëntengebruiksefficiëntie - china - nitrogen fertilizers - phosphorus fertilizers - food chains - food security - food costs - environmental impact - nutrient management - cycling - nutrient use efficiency - china

    Key words: Nitrogen, phosphorus, food chain, food pyramid, food system, food security, food cost, environmental impacts, nutrient cycling, nutrient management

    Nitrogen (N) and phosphorus (P) fertilizer applications have greatly contributed to the increased global food production during the last decades, but have also contributed to decreasing N and P use efficiencies (NUE and PUE) in the food production - consumption chain, and to increased N and P losses to air and water, with major ecological implications.

    The aim of this thesis is to increase the quantitative understanding of N and P flows and losses in the food production - consumption chain in China at regional level in the past 30 years and to develop strategies to increase NUE and PUE in the food chain. A novel ‘food chain’ approach and the NUFER model were developed to analyse N and P flows in crop production, animal production, food processing and retail, and households. Data were derived from statistical sources, literature and field surveys.

    Between 1980 and 2005, NUE and PUE decreased in crop production, increased in the animal production and decreased in the whole food chain. Total N losses to water and atmosphere almost tripled between 1980 (14.3 Tg) and 2005 (42.8 Tg), and P losses to water systems increased from 0.5 to 3.0 Tg. There were significant regional differences in NUE, PUE, and N and P losses; regions with high N and P losses were in Beijing and Tianjin metropolitans, Pearl River Delta, and Yangzi River Delta. Urban expansion is a major driving force for change; total N losses increased 2.9 folds, and P losses increased even 37 folds during the development of Beijing metropolitan, between 1978 and 2008. Scenario analyses indicated that implementation of a package of integrated nutrient management measures, combined with diet changes and increased imports of animal food and feed, are the most effective management options for increasing NUE and PUE, and for decreasing N and P losses.

    Application of the food chain approach and the NUFER model can help policy makers in China to plan food production - consumption chains, and thereby manage N and P flows in this chain at regional level.

    Adviesbasis voor de bemesting van akkerbouwgewassen : stikstof
    Geel, W.C.A. van; Haan, J.J. de - \ 2013 2013 (2013)20 maart.
    stikstofmeststoffen - akkerbouw - graansoorten - aardappelen - suikerbieten - voedergewassen - uien - grassen - groenbemesters - bemesting - nitrogen fertilizers - arable farming - cereals - potatoes - sugarbeet - fodder crops - onions - grasses - green manures - fertilizer application
    De stikstofbemestingsrichtlijnen geven de door de jaren heen gemiddelde optimale stikstofgift. De optimale stikstofgift is echter van veel factoren afhankelijk, zoals voorvrucht, bemestingsverleden, vochtvoorziening en ziektedruk. Op basis van de eigen ervaringen en kennis van percelen en gewassen kan de richtlijn dan ook aan de eigen situatie worden aangepast. Daar waar mogelijk zijn in deze adviesbasis richtlijnen gegeven voor dergelijke aanpassingen (o.a. onderwerken van groenbemesters en oogstresten en gebruik van dierlijke mest).
    Mineral Concentrates Pilot : synthesis of the results of 2011
    Velthof, G.L. - \ 2013
    Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2363) - 50
    kunstmeststoffen - mestverwerking - stikstof - concentraten - stikstofmeststoffen - drijfmest - fertilizers - manure treatment - nitrogen - concentrates - nitrogen fertilizers - slurries
    The agronomic and environmental impacts of the production of mineral concentrate and its use as mineral nitrogen (N) fertilizer are examined in a pilot. In this pilot, the mineral concentrate is applied as fertilizer above the application standard for manure, but within the total N application standard (i.e. sum of effective N from manure and mineral fertilizer N) of the Nitrates Directive. The research in 2011 included monitoring of the manure treatment installations, incubation studies to assess immobilization and denitrification of soil-applied mineral concentrate, pot experiments to determine N efficiency of mineral concentrate under controlled conditions, and field experiments to determine N efficiency of mineral concentrate when used for grassland and arable crops. This report summarizes the main results of these studies. The research data will serve for consultation with the European Commission on a possible permanent permission to use mineral concentrate as mineral N fertilizer.
    Influences of agricultural management practices on Arbuscular Mycorrhiza Fungal symbioses in Kenyan agro-ecosystems
    Muriithi-Muchane, M.N. - \ 2013
    Wageningen University. Promotor(en): Thomas Kuijper, co-promotor(en): B. Vanlauwe; J. Jefwa. - S.l. : s.n. - ISBN 9789461735133 - 201
    vesiculair-arbusculaire mycorrhizae - mycorrhizae - agro-ecosystemen - organische verbeteraars - stikstofmeststoffen - kunstmeststoffen - schimmels - plantenvoeding - bodemvruchtbaarheid - bodembiologie - gewasproductie - bodemstructuur - bodemkwaliteit - kenya - vesicular arbuscular mycorrhizas - mycorrhizas - agroecosystems - organic amendments - nitrogen fertilizers - fertilizers - fungi - plant nutrition - soil fertility - soil biology - crop production - soil structure - soil quality - kenya

    Conservation agriculture (CA) and integrated soil fertility management (ISFM) practices are receiving increased attention as pathways to sustainable high-production agriculture in sub-Saharan Africa. However, little is known about the effects of these practices on arbuscular mycorrhizal fungi (AMF). The study aimed at understanding the long-term effects of (i) ISFM and CA on AMF communities and functioning, and on glomalin concentrations. The study also aimed at understanding the (ii) role of AMF in soil aggregation, plant nutrition and crop yield under field conditions and (iii) combined effect of AMF and earthworms on soil aggregation, plant nutrition and crop yield under greenhouse conditions. The study was conducted in two long-term field trials. The ISFM trial was in Kabete (central Kenya) and compared fertilization (nitrogen and phosphorus) and organic amendments (farmyard manure, crop residue) for 32 years, while the CA trial was in Nyabeda (western Kenya) and compared effect of tillage (conventional versus no-tillage), residue application, cropping system (monocropping versus rotation) and N-fertilization for 5 years. Long-term use of mineral fertilizer and organic amendments, as well as tillage and N fertilization altered AMF species composition, but the changes were relatively minor. Organic amendments alone or in combination with NP fertilization increased AMF incidence, whereas no-tillage in the presence of residue increased spore abundance and root colonization. N fertilization increased root colonization but had a negative effect on spore abundance and species richness. Crop rotation had no effect on AMF. Glomalin was also sensitive to management, but the response was site-specific. Glomalin responded more to CA in Nyabeda than ISFM in Kabete. N fertilization and residue increased glomalin, especially under conventional tillage. Path analysis indicated that AMF symbiosis and glomalin enhanced soil aggregation and crop nutrition and yield in both sites. The positive role of AMF on crop nutrition was stronger in Kabete than Nyabeda. However, yield and nutrient use efficiency were (very) low in Kabete. There was no interaction between AMF and earthworms on soil aggregation, but AMF enhanced soil aggregation. AMF interacted positively with the epigeic earthworm to enhance nutrient uptake and biomass production, but the endogeic earthworm negatively affected AMF symbiosis and function. The study highlights the potential of ISFM and CA practices in enhancing AMF diversity and activity, and indicates factors limiting AMF functioning under ISFM and CA systems. While AMF are important for agro-ecosystem functioning, remedying the non-responsive character of soils, especially Kabete, through judicious management of nitrogen and organic amendments remains a first priority.

    Rijenbemesting in aardappelen : rijenbemesting versus breedwerpig en perspectief van nieuwe meststoffen : verslag van een veldproef op zuidwestelijke zeeklei in 2011
    Slabbekoorn, J.J. - \ 2012
    Westmaas : Praktijkonderzoek Plant & Omgeving, onderdeel van Wageningen UR, Business Unit AGV - 44
    akkerbouw - aardappelen - precisielandbouw - teeltsystemen - bemesting - proeven op proefstations - stikstofhoudende verbindingen - stikstofmeststoffen - lichte-matig zware kleigronden - rijpadensysteem - toedieningshoeveelheden - broeikaseffect - arable farming - potatoes - precision agriculture - cropping systems - fertilizer application - station tests - nitrogenous compounds - nitrogen fertilizers - clay loam soils - controlled traffic farming - application rates - greenhouse effect
    In opdracht van het Pogramma Precisielandbouw (PPL) is door PPO te Westmaas (ZH) op kleigrond een stikstof bemestingsproef uitgevoerd. De precisietoepassing van stikstofhoudende meststoffen draagt bij aan PPL doelen van energie-besparing en reductie van broeikas-emmissie in de zin dat mogelijkheden worden onderzocht om kunstmeststikstof te vervangen.
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