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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Legacy effects of anaerobic soil disinfestation on soil bacterial community composition and production of pathogen-suppressing volatiles
Os, G.J. van; Agtmaal, M. van; Hol, G. ; Hundscheid, M.P.J. ; Runia, W.T. ; Hordijk, C. ; Boer, W. de - \ 2015
Frontiers in Microbiology 6 (2015). - ISSN 1664-302X
pythium root-rot - soilborne plant-diseases - microbial-populations - organic amendments - biological-control - bulbous iris - fungistasis - growth - biocontrol - diversity
There is increasing evidence that microbial volatiles (VOCs) play an important role in natural suppression of soil-borne diseases, but little is known on the factors that influence production of suppressing VOCs. In the current study we examined whether a stress-induced change in soil microbial community composition would affect the production by soils of VOCs suppressing the plant-pathogenic oomycete Pythium. Using pyrosequencing of 16S ribosomal gene fragments we compared the composition of bacterial communities in sandy soils that had been exposed to anaerobic disinfestation (AD), a treatment used to kill harmful soil organisms, with the composition in untreated soils. Three months after the AD treatment had been finished, there was still a clear legacy effect of the former anaerobic stress on bacterial community composition with a strong increase in relative abundance of the phylum Bacteroidetes and a significant decrease of the phyla Acidobacteria, Planctomycetes, Nitrospirae, Chloroflexi, and Chlorobi. This change in bacterial community composition coincided with loss of production of Pythium suppressing soil volatiles (VOCs) and of suppression of Pythium impacts on Hyacinth root development. One year later, the composition of the bacterial community in the AD soils was reflecting that of the untreated soils. In addition, both production of Pythium-suppressing VOCs and suppression of Pythium in Hyacinth bioassays had returned to the levels of the untreated soil. GC/MS analysis identified several VOCs, among which compounds known to be antifungal, that were produced in the untreated soils but not in the AD soils. These compounds were again produced 15 months after the AD treatment. Our data indicate that soils exposed to a drastic stress can temporarily lose pathogen suppressive characteristics and that both loss and return of these suppressive characteristics and that both loss and return of these suppressive characteristics coincides with shifts in the soil bacterial community composition. Our data are supporting the suggested importance of microbial VOCs in the natural buffer of soils against diseases caused by soil-borne pathogens.
Sclerotium rolfsii dynamics in soil as affected by crop sequences
Leoni, C. ; Braak, C.J.F. ter; Gilsanz, J.C. ; Dogliotti, S. ; Rossing, W.A.H. ; Bruggen, A.H.C. van - \ 2014
Applied Soil Ecology 75 (2014). - ISSN 0929-1393 - p. 95 - 105.
southern blight - vegetable farms - soilborne pathogens - population-dynamics - organic amendments - north-carolina - management - rotations - survival - residues
Crop rotation has been used for the management of soilborne diseases for centuries, but has not often been planned based on scientific knowledge. Our objective was to generate information on Sclerotium rolfsii dynamics under different crop or intercrop activities, and design and test a research approach where simple experiments and the use of models are combined to explore crop sequences that minimize Southern blight incidence. The effect of seventeen green manure (GM) amendments on sclerotia dynamics was analyzed in greenhouse and field plot experiments during two years. The relative densities of viable sclerotia 90 days after winter GM (WGM) incorporation were generally lower than after summer GM (SGM) incorporation, with average recovery values of 60% and 61% for WGM in the field, 66% and 43% for WGM in the greenhouse, and 162% to 91% for SGM in the greenhouse, in 2009 and 2010, respectively. Sclerotia survival on day d after GM amendment was described by the model Sf = Si × exp(-b × d), relating initial (Si) and final (Sf) sclerotia densities. Relative decay rates of the sclerotia (b) in SGM amended soil were largest for alfalfa (0.0077 ± 0.0031 day-1) and sudangrass (0.0072 ± 0.0030 day-1). In WGM amended soil, the largest b values were for oat (0.0096 ± 0.0024 day-1), wheat (0.0090 ± 0.0024 day-1) and alfalfa (0.0087 ± 0.0023 day-1). The effect of three cropping sequences (sweet pepper–fallow, sweet pepper–black oat and sweet pepper–onion) on sclerotia dynamics was analyzed in microplot experiments, and the data were used to calibrate the model Pf = Pi/(a + ßPi), relating initial (Pi) and final (Pf) sclerotia densities. Median values for the relative rate of population increase at low Pi (1/a, dimension less) and the asymptote (1/ß, number of viable sclerotia in 100 g of dry soil) were 8.22 and 4.17 for black oat (BO), 1.13 and 8.64 for onion (O), and 6.26 and 17.93 for sweet pepper (SwP). By concatenating the two models, sclerotia population dynamics under several crop sequences were simulated. At steady state, the sequence SwP–O–Fallow–BO resulted in the lowest long-term sclerotia density (7.09 sclerotia/100 g soil), and SwP–Fallow in the highest (17.89 sclerotia/100 g soil). The developed methodology facilitates the selection of a limited number of rotation options to be tested in farmers’ fields.
Fusarium oxysporum f.sp. cepae dynamics: in-plant multiplication and crop sequence simulations
Leoni, C. ; Vries, M. de; Braak, C.J.F. ter; Bruggen, A.H.C. van; Rossing, W.A.H. - \ 2013
European Journal of Plant Pathology 137 (2013)3. - ISSN 0929-1873 - p. 545 - 561.
f-sp melonis - ecological intensification - verticillium-dahliae - disease suppression - population-dynamics - organic amendments - soilborne diseases - farming systems - root diseases - wilt pathogen
To reduce Fusarium Basal Rot caused by Fusarium oxysporum f.sp. cepae (Foc) through crop rotation, plant species should be selected based on Foc multiplication in their roots. Foc multiplication rates in 13 plant species were tested in a greenhouse. All plant species enabled Foc multiplication. The lowest Foc levels (cfu g-1 dry root) were found for wheat, sunflower, cowpea and millet, the highest for black bean. The highest Foc levels per plant were calculated for sudan grass. These data were used to calibrate the model Pf¿=¿Pi/(a¿+¿ßPi) relating final (Pf) and initial (Pi) Foc levels in the soil. The rate of population increase at low Pi (1/a) was highest for onion and black oat and smallest for sunflower. The pathogen carrying capacity (1/ß) was highest for black oat and black bean, and lowest for wheat, cowpea and foxtail millet. Foc soil population dynamics was simulated for crop sequences by concatenating Pi-Pf values, considering instantaneous or gradual pathogen release after harvest. Different soil Foc populations were attained after reaching steady states. Foc populations in the sequence onion –foxtail millet - wheat – cowpea were 67 % lower than in the sequence onion – sudan grass - black oat - black beans. In this work, by combining detailed greenhouse experiments with modelling, we were able to screen crops for their ability to increase Foc population and to explore potential crop sequences that may limit pathogen build-up
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.

Short term effects of bioenergy by-products on soil C and N dynamics, nutrient availability and biochemical properties
Galvez, A. ; Sinicco, T. ; Cayuela, M.L. ; Mingorance, M.D. ; Fornasier, F. ; Mondini, C. - \ 2012
Agriculture, Ecosystems and Environment 160 (2012). - ISSN 0167-8809 - p. 3 - 14.
nitrous-oxide emission - microbial biomass - enzyme-activities - crop residues - organic amendments - carbon - mineralization - management - decomposition - composts
The shift towards a biobased economy will probably trigger the application of bioenergy by-products to the soil as either amendments or fertilizers. However, limited research has been done to determine how this will influence C and N dynamics and soil functioning. The aim of this work was to investigate the effects of different bioenergy by-products on C and N mineralisation, nutrient availability and microbial content and activity of amended soil and compare them to other more commonly used organic amendments. Two agricultural soils were amended (0.5% w/w) with four different bioenergy by-products (anaerobic digestate, rapeseed meal, bioethanol residue, biochar) and three other commonly used organic amendments (sewage sludge and two composts) and incubated at 20 degrees C in the laboratory for 30 days. During incubation, soil CO2 and N2O evolution were measured every 4 h by an automatic chromatographic system. After 2, 7 and 30 days of incubation, soil samples were analysed for K2SO4-extractable C, N, NO3-, NH4+ and P, microbial biomass C and three enzymatic activities (beta-glucosidase, alkaline phosphatase and leucine aminopeptidase). Soil amendment led to a general increase in soil respiration, available N and P and microbial content and activity, but with remarkably different dynamics and values. Particularly, rapeseed meal and the bioethanol by-product led to N2O emissions and the greatest increases in soil respiration, N availability and enzymatic activity compared with the other amendments. The exception was represented by biochar that did not cause any significant variation with respect to the control, but promoted C accumulation. According to their impact on soil biochemical properties, the materials can be ranked as follows: rapeseed meal, bioethanol residue > anaerobic digestate, sewage sludge > composts > biochar. For each measured parameter, soil properties did not affect the response pattern found for the different treatments, but modified the magnitude of the response. In particular, soil respiration and enzymatic activity were higher in the slightly acidic soil, while greater values of available P were found in the alkaline soil. This study clearly indicates that the impact on GHG emissions and soil functioning of bioenergy byproducts needs to be taken into account for a correct life cycle assessment of the bioenergy chain. Moreover, when properly managed, they may represent an effective alternative to usual amendments to improve the quality and nutrient balance of amended soils.
Effects of compost amendment and the biocontrol agent Clonostachys rosea on the development of charcoal rot (Macrophomina phaseolina) on cowpea
Ndiaye, M. ; Termorshuizen, A.J. ; Bruggen, A.H.C. van - \ 2010
Journal of plant pathology - Formerly Rivista di patologia vegetale 92 (2010)1. - ISSN 1125-4653 - p. 173 - 180.
soil microbial communities - organic amendments - biological-control - root-rot - sclerotia - survival - solarization - suppression - management - pathogens
Macrophomina phaseolina is a destructive pathogen causing charcoal rot of cowpea and other crops in the semi- arid areas of the Sahel (north-west Africa). Chemical management is not feasible in conditions of subsistence farming, and the plurivorous nature of the fungus limits the effectiveness of some cultural methods. This study aimed at identifying the effects of composting on the survival of M. phaseolina and of soil application of compost alone or in combination with the biocontrol agent Clonostachys rosea on inoculum density of M. phaseolina and on cowpea production. Inside the compost heap with diseased cowpea residues, the temperature reached 52 to 60°C and completely destroyed M. phaseolina microsclerotia. Addition of compost to planting holes significantly suppressed charcoal rot disease. Among the doses tested 6 tonnes of compost alone or supplemented with 50 kg NPK ha-1 resulted in 28-45% lower Area-Under- the-Disease-Progress-Curves (AUDPC) and 43-66% higher cowpea production. The addition of compost combined with C. rosea in the planting holes reduced the AUDPC up to 4-fold and increased the grain yield 2-5- fold. The best treatment was a mixture of two C. rosea isolates and the compost.
Nematode succession during composting and the potential of the nematode community as an indicator of compost maturity
Steel, H. ; Peña, E. de la; Fonderie, P. ; Willekens, K. ; Borgonie, G. ; Bert, W. - \ 2010
Pedobiologia 53 (2010)3. - ISSN 0031-4056 - p. 181 - 190.
plant-parasitic nematodes - municipal solid-waste - bacterivorous nematodes - bacterial community - organic amendments - biological-control - enzyme-activities - faunal analysis - soil nematodes - food-web
One of the key issues in compost research is to assess when the compost has reached a mature stage. The maturity status of the compost determines the quality of the final soil amendment product. The nematode community occurring in a Controlled Microbial Composting (CMC) process was analyzed with the objective of assessing whether the species composition could be used as a bio-indicator of the compost maturity status. The results obtained here describe the major shifts in species composition that occur during the composting process. Compared to terrestrial ecosystems, nematode succession in compost differs mainly in the absence of K-strategists and numerical importance of diplogastrids. At the beginning of the composting process (thermophilic phase), immediately after the heat peak, the nematode population is primarily built by bacterial feeding enrichment opportunists (cp-1) (Rhabditidae, Panagrolaimidae, Diplogastridae) followed by the bacterial-feeding general opportunists (cp-2) (Cephalobidae) and the fungal-feeding general opportunists (Aphelenchoididae). Thereafter, during the cooling and maturation stage, the bacterial-feeding-predator opportunistic nematodes (Mononchoides sp.) became dominant. Finally, at the most mature stage, the fungal-feeding Anguinidae (mainly Ditylenchus filimus) were most present. Both, the Maturity Index (MI) and the fungivorous/bacterivorous ratio (f/b ratio), increase as the compost becomes more mature (ranging, respectively, from 1 to 1.86 and from 0 to 11.90). Based on these results, both indices are suggested as potential suitable tools to assess compost maturity
Kunstmestvervangers onderzocht; een tussenstand
Velthof, G.L. - \ 2010
Wageningen : Wageningen UR (BO-12.02-infobladen 02) - 2
mest - kunstmeststoffen - organische verbeteraars - mestverwerking - manures - fertilizers - organic amendments - manure treatment
Informatieblad over kunstmestvervangers
Mogelijke effecten van bodembewerking en mulch op roofmijten in de grond: een literatuurstudie
Geerts, R.H.E.M. ; Belder, E. den; Elderson, J. - \ 2009
Wageningen : Plant Research International (Nota / Plant Research International 649) - 14
grondbewerking - mulches - roofmijten - bodemvruchtbaarheid - groenbemesters - pesticiden - organische verbeteraars - organische meststoffen - gewasbescherming - bodemweerbaarheid - tillage - predatory mites - soil fertility - green manures - pesticides - organic amendments - organic fertilizers - plant protection - soil suppressiveness
Om tot een vermindering van het gebruik van (chemische) bestrijdingsmiddelen te komen is een verhoging van ziekte- en plaagwerende eigenschappen van de bodem noodzakelijk. Grondbewerking voor en tijdens de teelt, grondsoort,organische mest en andere organische toevoegingen kunnen de bodemweerbaarheid beïnvloeden. In tabelvorm wordt een overzicht gegeven van de verschillende grondbewerkingen in relatie met een aantal bodemorganismen. De opzet van dit overzicht is : inzicht krijgen in de mogelijke effecten van bodembewerking op roofmijten die mogelijk op hun beurt effecten van bodembewerking kunnen hebben op de bodemfasen van trips. Een aantal zaken die naar voren zijn dat over het algemeen kan gezegd worden dat roofmijten gevoelig zijn voor grondbewerking
Biological soil disinfestation (BSD), a new control method for potato brown rot, caused by Ralstonia solanacearum race 3 biovar 2
Messiha, N.A.S. ; Diepeningen, A.D. van; Wenneker, M. ; Beuningen, A.R. van; Janse, J.D. ; Coenen, G.C.M. ; Termorshuizen, A.J. ; Bruggen, A.H.C. van; Blok, W.J. - \ 2007
European Journal of Plant Pathology 117 (2007)4. - ISSN 0929-1873 - p. 403 - 415.
gradient gel-electrophoresis - pseudomonas-solanacearum - organic amendments - plant-pathogens - fatty-acid - survival - resistance - strains - tubers - crops
The potential of Biological Soil Disinfestation (BSD) to control potato brown rot, caused by Ralstonia solanacearum race 3 biovar 2, was investigated. BSD involves the induction of anaerobic soil conditions by increasing microbial respiration through incorporation of fresh organic amendments (here: grass or potato haulms) and by reducing re-supply of oxygen by covering with airtight plastic sheets. Control treatments were left without cover and amendment, or amended without covering or covered only without amendment. The effect of BSD on survival of R. solanacearum was tested at three different scales: in 1-l glass mesocosms under laboratory conditions, in 1.2-m-diam microplots positioned in an outdoor quarantine field, and in a naturally infested commercial field. Within a few days, anaerobic conditions developed in the BSD-treated soils. In the mesocosm and microplot experiment, anaerobic conditions persisted till the end of the 4-week experimental period. In the field experiment, the period of anaerobiosis was shorter due to birds damaging the plastic cover. In all three experiments, BSD reduced soil populations of R. solanacearum significantly by 92.5% to >99.9% compared to the non-amended and uncovered control treatments. In the field experiment, BSD also resulted in a significant reduction of R. solanacearum survival in potato tubers buried at 15 or 35 cm and in the rapid decomposition of superficially buried potatoes remaining after harvesting, thus destroying an important inoculum reservoir of R. solanacearum. The treatments with grass amendment only or covering with only plastic did not result in anaerobic conditions and did not decrease R. solanacearum populations during the experimental period. PCR-DGGE analyses of 16S-rDNA from soil samples of the various treatments in the mesocosm and microplot experiments revealed that BSD hardly affected bacterial diversity but did result in clear shifts in the composition of the bacterial community. The possible implications of these shifts are discussed. It is concluded that BSD has the potential to strongly decrease soil infestation levels of R. solanacearum and to become an important element in a sustainable and effective management strategy for potato brown rot, especially in areas where the disease is endemic.
Intersectorale samenwerking in de biologische landbouw : naar gesloten kringlopen in de biologische landbouw, een beleidsagenda
Bos, J.F.F.P. ; Wit, J. de - \ 2006
Wageningen : Wageningen UR - 14
kringlopen - mest - organische verbeteraars - voedingsstoffen - diervoedering - voer - biologische landbouw - gesloten systemen - landbouwbeleid - beleid - cycling - manures - organic amendments - nutrients - animal feeding - feeds - organic farming - closed systems - agricultural policy - policy
Suppressiveness of 18 composts against 7 pathosystems: Variability in pathogen response
Termorshuizen, A.J. ; Rijn, E. van; Gaag, D.J. van der; Alabouvette, C. ; Chen, Y. ; Lagerlöf, J. ; Malandrakis, A.A. ; Paplomatas, E.J. ; Rämert, B. ; Ryckeboer, J. ; Steinberg, C. ; Zmora-Nahum, S. - \ 2006
Soil Biology and Biochemistry 38 (2006)8. - ISSN 0038-0717 - p. 2461 - 2477.
soil microbial communities - soilborne plant-pathogens - rhizoctonia-solani - damping-off - phytophthora-cinnamomi - organic amendments - container media - pythium-ultimum - potting mixes - waste
Compost is often reported as a substrate that is able to suppress soilborne plant pathogens, but suppression varies according to the type of compost and pathosystem. Reports often deal with a single pathogen while in reality crops are attacked by multiple plant pathogens. The goal of the present study was to evaluate the disease suppression ability of a wide range of composts for a range of plant pathogens. This study was conducted by a consortium of researchers from several European countries. Composts originated from different countries and source materials including green and yard waste, straw, bark, biowaste and municipal sewage. Suppressiveness of compost-amended (20% vol./vol.) peat-based potting soil was determined against Verticillium dahliae on eggplant, Rhizoctonia solani on cauliflower, Phytophthora nicotianae on tomato, Phytophthora cinnamomi on lupin and Cylindrocladium spathiphylli on Spathiphyllum sp., and of compost-amended loamy soil (20% vol./vol.) against R. solani on Pinus sylvestris and Fusarium oxysporum f. sp. lini on flax. From the 120 bioassays involving 18 composts and 7 pathosystems, significant disease suppression was found in 54% of the cases while only 3% of the cases showed significant disease enhancement. Pathogens were affected differently by the composts. In general, prediction of disease suppression was better when parameters derived from the compost mixes were used rather than those derived from the pure composts. Regression analyses of disease suppression of the individual pathogens with parameters of compost-amended peat-based mixes revealed the following groupings: (1) competition-sensitive: F. oxysporum and R. solani/cauliflower; (2) rhizosphere-affected: V. dahliae; (3) pH-related: P. nicotianae; and (4) specific/unknown: R. solani/pine, P. cinnamomi and C. spathiphylli. It was concluded that application of compost has in general a positive or no effect on disease suppression, and only rarely a disease stimulating effect.
Onkruidvrije zaaistroken : doorontwikkeling van de machine en praktijkproeven in 2005
Achten, V.T.J.M. ; Bleeker, P.O. ; Lotz, P.A. ; Molema, G.J. - \ 2005
Wageningen : Agrotechnology & Food Innovations (Rapport / Agrotechnology & Food Innovations 578) - ISBN 9067549886
onkruidbestrijding - grondbewerking tussen de rijen - zaaien - compost - organische verbeteraars - mechanisatie - biologische landbouw - stroken - weed control - interrow cultivation - sowing - composts - organic amendments - mechanization - organic farming - strips
Onkruidbeheersing door het aanbrengen van onkruidvrije zaaistroken : machineontwikkeling en orienterende praktijkproeven
Achten, V.T.J.M. ; Bleeker, P.O. ; Molema, G.J. - \ 2005
Wageningen : Agrotechnology & Food Innovations (Rapport / Agrotechnology & Food Innovations 333) - ISBN 9067548863
onkruidbestrijding - grondbewerking tussen de rijen - zaaien - compost - organische verbeteraars - mechanisatie - biologische landbouw - weed control - interrow cultivation - sowing - composts - organic amendments - mechanization - organic farming
Voor eendenstromest liggen er kansen
Buisonjé, F.E. de - \ 2005
De Pluimveehouderij 35 (2005)6. - ISSN 0166-8250 - p. 18 - 19.
compost - mest - biologische landbouw - dierlijke meststoffen - pluimveemest - organische verbeteraars - bodemvruchtbaarheid - plantenvoeding - cultuurmethoden - kosten-batenanalyse - haalbaarheidsstudies - composts - manures - organic farming - animal manures - poultry manure - organic amendments - soil fertility - plant nutrition - cultural methods - cost benefit analysis - feasibility studies
Compost is gewild in de (biologische) akkerbouw en groenteteelt. Wanneer tegen lage kosten een kwalitatief hoogwaardige compost kan worden gemaakt uit strorijke eendemest, kan dit de mestafzet bevorderen.
Pig slurry reduces the survival of Raltstonia solanacearum biovar 2 in soil
Gorissen, A. ; Overbeek, L.S. van; Elsas, J.D. van - \ 2004
Canadian Journal of Microbiology 50 (2004)8. - ISSN 0008-4166 - p. 587 - 593.
polymerase-chain-reaction - gradient gel-electrophoresis - pseudomonas-solanacearum - organic amendments - bacterial wilt - dna extraction - solarisation - solarization - suppression - climates
The effect of added pig slurry and solarization on the survival of Ralstonia solanacearum biovar 2 strain 1609 in soil was analysed in soil microcosms and field plots. In addition, the invasion of potato plants by R. solanacearum and the development of disease symptoms were determined, as measures of induced disease suppressiveness. In untreated soil, R. solanacearum showed slow population declines in both microcosms and the field from, initially, 106-107 to 103-104 CFU·(g dry soil)-1 in about 9 weeks. The suppressiveness assays of these untreated soils after this period revealed that most of the plants that were used developed wilting symptoms and (or) contained the pathogen in their lower stem parts, as shown by immunofluorescence colony staining and PCR. The addition of pig slurry resulted in a significantly lower population size of R. solanacearum as well as reduced numbers of infected and (or) diseased plants in the soil suppressiveness tests. On the other hand, solarization of soil also decreased R. solanacearum survival but did not enhance soil suppressiveness as measured by development of disease symptoms and (or) plant invasion after 9 weeks. Combined soil solarization and pig slurry addition showed an additive effect of both treatments. Healthy-looking plants, primarily from soils treated with pig slurry and solarization, incidentally revealed the latent presence of R. solanacearum in the lower stem parts. The mechanism behind the enhanced population declines and disease suppressiveness induced by pig slurry is unclear but shifts in community profiles were clearly discernible by PCR - denaturing gradient gel electrophoresis 9 weeks after pig slurry addition in the field experiment, indicating induced changes in the bacterial community structure.Key words: soil suppressiveness, organic amendment, solarization, DGGE analysis, immunofluorescence colony staining. Nous avons analysé l'impact de l'ajout de lisier de porc et de la solarisation sur la survie dans le sol de la souche 1609 de Ralstonia solanacearum biovar 2, dans des microcosmes du sol et des placettes de champs. De plus, nous avons déterminé la capacité à supprimer les maladies induites en mesurant l'invasion des plants de pommes de terre par R. solanacearum et le développement des symptômes de maladies. Dans le sol non traité, la population de R. solanacearum a lentement décliné dans les microcosmes et dans le champ, passant au départ de 106-107 à 103-104 UFC par gramme de sol sec dans une intervalle d'environ 9 semaines. Les analyses des capacités suppressives de ces sols non traités à la suite de cette période ont révélé que la plupart des plants utilisés ont développé des symptômes de flétrissement et/ou contenaient des pathogènes dans les parties inférieures de leur tige, tel que vu par coloration immunofluorescente des colonies (CIF) et par PCR. L'ajout de lisier de porc a permis d'obtenir une taille de population de R. solanacearum significativement inférieure de même qu'un nombre inférieur de plantes infectées et/ou malades dans les tests de capacités suppressives des sols. En outre, la solarisation des sols a également diminué la survie de R. solanacearum mais n'a pas augmenté la capacité suppressive des sols tel que mesurée par le développement de symptômes de maladies et/ou par l'invasion des plantes après neuf semaines. La combinaison de la solarisation des sols et de l'ajout de lisier de porc a entraîné un effet additif sur les deux traitements. Des plants d'apparence saine, provenant principalement de sols traités avec du lisier de porc et avec la solarisation, ont incidemment révélé la présence latente de R. solanacearum dans les parties inférieures des tiges. Les mécanismes responsables du déclin accéléré des populations et de la suppression des maladies induits par le lisier de porc sont nébuleux, mais il fut possible de discerner dans l'expérience dans le champ des déplacements dans les profils des communautés par PCR-DGGE, neuf semaines après l'ajout de lisier de porc, ce qui signale des changements induits dans la structure des communautés bactériennes.Mots clés : capacité suppressive des sols, enrichissement organique, solarisation, analyse par DGGE, coloration immunofluorescente des colonies.[Traduit par la Rédaction]
Microbial diversity in archived agricultural soils; the past as a guide to the future
Dolfing, J. ; Vos, A. ; Bloem, J. ; Kuikman, P.J. - \ 2004
Wageningen : Alterra (Alterra-rapport 916) - 55
bodembiologie - bodembacteriën - organische verbeteraars - mest - bodembeheer - organisch bodemmateriaal - geschiedenis - landbouwgronden - microbiële diversiteit - soil biology - soil bacteria - organic amendments - manures - soil management - soil organic matter - history - agricultural soils - microbial diversity
Bacterial diversity and bacterially mediated processes are considered key to soil ecosystem functioning through decomposition and mineralization. However, there is a lack of understanding as to how activity and diversity of prokaryotic communities respond to changes in the environment. At present this issue is mostly addressed by real-time monitoring of long term field experiments, which is costly and slow. Using modern molecular methods we re-analyzed soil samples of up to 50 years old that have been stored in the Alterra soil archive TAGA. We showed that it is indeed possible to detect bacterial fingerprints in those samples and that fingerprints from different samples can be distinctly different, for example between fields that have or have not received organic amendments. These results are a promising first step towards unlocking the microbial information present in archived soil samples. This will help to assess the (likelihood of) changes in soil microbial diversity in response to environmental change (climate change) and human interference (fertilization) and to establish a reference condition and situation. This may further enable coupling to more functional assessments of soil functioning in standardized decomposition essays with the stored samples with known differences in diversity.
Plantversterkers in spruitkool 2002
Vlaswinkel, M.E.T. ; Kruistum, G. van - \ 2003
Westmaas : Praktijkonderzoek Plant & Omgeving B.V. - 49
spruitjes - koolsoorten - gewasbescherming - windschade - hagelschade - vorstwering - winterhardheid - bladval - gewassen, groeifasen - ziektebestrijdende teeltmaatregelen - organische verbeteraars - brussels sprouts - cabbages - plant protection - wind damage - hail damage - frost protection - winter hardiness - leaf fall - crop growth stage - cultural control - organic amendments
Om bij spruitkool de spruiten te beschermen tegen vorst, hagel, wind en dergelijke in de winter, moet er voldoende blad aan de spruitkoolplant blijven zitten. Daarnaast is het belangrijk dat dit vitaal en groeikrachtig blad is. Dit kan dan ook worden gebruikt voor de assimilatie van de plant en eventuele groei van de spruiten. De huidige late rassen vertonen vaak een beeld van een te vroege bladval. Hierdoor ontstaan in strenge winters problemen zoals vorstschade en dergelijke. Doel van dit project is te onderzoeken of plantversterkers kunnen bijdragen aan de vitaliteit van het spruitenblad.
Typologie bermgraskwaliteit : typologie van de milieuhygiënische kwaliteit van bermgras voor het onderwerken op landbouwgronden
Bok, A.J. ; Kopinga, J. ; Schnaar, M. ; Spijker, J.H. - \ 2001
Wageningen : Alterra (Alterra-rapport 246) - 48
grassen - wegbermen - besmetters - arsenicum - zware metalen - landverbetering - organische verbeteraars - kwaliteit - nederland - grasses - roadsides - contaminants - arsenic - heavy metals - land improvement - organic amendments - quality - netherlands
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