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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Agronomic and socioeconomic sustainability of farming systems : A case in Chencha, South Ethiopia
Dersseh, Waga Mazengia - \ 2017
University. Promotor(en): Paul Struik, co-promotor(en): Rogier Schulte. - Wageningen : Wageningen University - ISBN 9789463436830 - 157
potatoes - solanum tuberosum - ethiopia - food security - farming systems - mixed farming - sustainability - optimization - efficiency - farm surveys - household surveys - socioeconomics - self sufficiency - profits - training - agronomic characteristics - productivity - soil fertility - rotation - animal feeding - improved varieties - inorganic fertilizers - aardappelen - ethiopië - voedselzekerheid - bedrijfssystemen - gemengde landbouw - duurzaamheid (sustainability) - optimalisatie - efficiëntie - bedrijfsonderzoeken - huishoudonderzoeken - sociale economie - zelfvoorziening - winsten - opleiding - agronomische kenmerken - productiviteit - bodemvruchtbaarheid - rotatie - diervoedering - veredelde rassen - anorganische meststoffen

Potato has multiple benefits and thus can play a vital role in ensuring food security in Ethiopia. However, for diverse reasons, its productivity is low. The farming systems in Ethiopia in which potato is grown, are predominantly mixed farming systems.

Most of the research in Ethiopia is focused on crop-specific constraints and thus there is limited research in which the interrelations between crop and livestock management practices are investigated. There is also not enough research focused on combined analysis of soil nutrient and animal feed balances and agronomic and socioeconomic efficiencies at farm level.

This study assessed production constraints and agronomic and socioeconomic sustainability of the farming systems in South Ethiopia and explored the possible synergetic options to alleviate major constraints. More specifically, the study intended to quantify the variation in input and output among farms, to identify constraints hindering expansion of potato production, to evaluate the sustainability of the farming systems at farm level, to identify constraints of sustainable intensification, and to explore synergetic solutions for the major constraints. Different research approaches were used ranging from lab analysis, household surveys, group discussions, to farm surveys.

Results showed that constraints related to input and product use in potato production vary across households indicating a need for a pluriform advisory model recognizing (and building upon alleviation of) the diversity of constraints identified in this analysis. The sustainability of the farming system is constrained by low agricultural productivity, low soil fertility, poor labour efficiency and limited economic return associated with improper crop rotation, inappropriate soil fertility management practices, shortage of animal feed, labour- and economically inefficient farm practices and labour shortage. However, there is ample scope to overcome the major constraints and simultaneously to optimize farm management.

The core messages of the study can be summarized as follows:

1) the current potato production is characterized by low productivity and economic returns due to various socioeconomic, agronomic and biological factors;

2) the soil fertility is low and there is uneven distribution of nutrients over plots with relatively high fertility levels in the homestead areas;

3) the current labour shortage can be attributed to mainly inefficiency of agricultural management practices and labour migration to towns for economic reasons indicating that the farming system is not sustainable in terms of labour;

4) considering the direct return from animal production, most of the farms had very low gross margin with the current management system and this reduced the overall operating profit of farms. The low return from animal rearing was offset by the relatively high profit from crop production indicating the benefit of mixed farming system in sustaining agricultural production; and

5) each farm can have a wide range of optimized solutions mainly through introduction of improved technologies and subsequent redesigning of the farm managements.

In general, the findings of the current study indicate that it is worthwhile to assess the sustainability of agricultural production in different farming systems and agro-ecologies of Ethiopia. In addition, the combined effect of introducing improved agricultural technologies and subsequent reconfiguring the farm management is very crucial to increase and sustain agricultural production.

Production efficiency of mussel bottom culture
Capelle, Jacob J. - \ 2017
University. Promotor(en): Aad Smaal; P.M.J. Herman, co-promotor(en): Jeroen Wijsman. - Wageningen : Wageningen University - ISBN 9789463430869 - 240
mussels - mussel culture - bottom culture - efficiency - population dynamics - culture techniques - biomass production - improvement - shellfish culture - aquaculture - mossels - mosselteelt - bodemcultuur - efficiëntie - populatiedynamica - kweektechnieken - biomassa productie - verbetering - schaal- en schelpdierenteelt - aquacultuur

Mussel bottom culture is an extensive type of aquaculture; it depends on natural resources for feed, seed and space. It consists of the translocation of seed from natural beds to designed culture areas, where mussel farmers try to improve production efficiency. Production efficiency is measured by the relative biomass production (RBP) expressed as units of biomass harvested from one unit of biomass seeded, it increases with mussel growth and decreases with mussel mortality. Mussel bottom culture makes use of nature and also depends on nature. Cultured mussels are subject to similar environmental factors that influence growth and mortality on natural mussel beds, with additional effects of anthropogenic factors. In this thesis we focus on dynamics of mussel beds and the impact and effectivity of culture activities on mussel production yield. The major objectives are stated as: (1) to better understand the population dynamics of subtidal mussel populations, (2) to analyze what factors determine production efficiency in mussel bottom culture and how this can be improved. On natural mussel beds mussels organise in patterns that enhance food delivery and resilience of the bed. On culture plots mussels are seeded in concentric seeding patterns. Seeding techniques concentrate mussels locally within the culture plot area, resulting in high local mussel densities; this increases competition and limits the spatial re-organisation of mussels in the bed. Consequently, seeding on culture plots is followed by a large size and density dependent seeding loss that ranges from about 40% for seed from fishery to 69% for smaller SMC seed. This loss was the major factor in determining the maximum RBP. Losses in the grow-out stage were substantially lower, a subsequent density dependent loss was found for smaller mussels (<30 mm), and a non-density dependent loss for larger mussels (>30 mm). Shore crab predation is an important factor contributing to the higher losses at seeding. The effect of shore crab predation on mussel biomass production is higher than expected from previous studies. In an experiment on an intertidal culture plot in the Oosterschelde (NL), we observed that shore crab predation peaks directly after seeding and accounted for 33% of the total losses within five weeks after seeding. Spatial patterns in the survival rates of natural mussel beds in the Wadden Sea show better seed survival in areas with intermediate salinity (mean annual salinity 17.5-22.5 mg l-1). This suggests that mussel survival is negatively related to sea star distribution, which is largely controlled by salinity. Natural beds that escape predation are found at lower salinities and mussels on these beds showed low growth rates, also because of a lower food quality in these areas. Mussel culture strongly affects the population dynamics of the subtidal mussel population, through relaying of mussels from natural mussel beds to culture plots. Culture plots are located in more saline regions of the Wadden Sea (mean annual salinity 25.8 mg l-1), compared to natural mussel beds. This activity increased mussel growth and survival because food quality on culture plots is high and predation is prevented. As a result, average biomass production is higher on culture plots than on natural mussel beds and this difference increases over time. A more efficient seed use on the available area, that can be obtained by reducing seeding losses will increase RBP, maximum biomass production and increases maximum profit. Our results suggest that this can be achieved by seeding homogeneously in low densities.

How to achieve resource use efficiency in integrated food and biobased value chains?
Annevelink, E. ; Gogh, J.B. van; Bartels, P.V. ; Broeze, J. ; Dam, J.E.G. van; Groot, J.J. ; Koenderink, N.J.J.P. ; Oever, M.J.A. van den; Snels, J.C.M.A. ; Top, J.L. ; Willems, D.J.M. - \ 2017
Wageningen : Wageningen Food & Biobased Research (Wageningen Food &amp; Biobased Research report 1720) - ISBN 9789463431163 - 23
resources - biobased economy - food chains - food biotechnology - biomass - change - sustainability - value chain analysis - efficiency - use efficiency - food - resource management - integrated systems - hulpbronnen - voedselketens - voedselbiotechnologie - biomassa - verandering - duurzaamheid (sustainability) - waardeketenanalyse - efficiëntie - gebruiksefficiëntie - voedsel - hulpbronnenbeheer - geïntegreerde systemen
Exergy analysis in industrial food processing
Zisopoulos, F.K. - \ 2016
University. Promotor(en): Remko Boom, co-promotor(en): Atze Jan van der Goot. - Wageningen : Wageningen University - ISBN 9789462578326 - 229
thermodynamics - energy - physical properties - food production - drying - food industry - efficiency - thermodynamica - energie - fysische eigenschappen - voedselproductie - drogen - voedselindustrie - efficiëntie

The sustainable provision of food on a global scale in the near future is a very serious challenge. This thesis focuses on the assessment and design of sustainable industrial food production chains and processes by using the concept of exergy which is an objective metric based on the first and second law of thermodynamics. Three case studies are presented, two on a chain level (industrial bread and mushroom production), and one on a process level (conceptual spray drying of a lactose solution). Furthermore, industrial food production chains are categorized as thermodynamic archetypes and general rules are derived for their sustainable design exergy-wise. Additional methodological aspects related to e.g. the impact of system boundaries, the allocation of exergy values to waste streams, and the influence of the selection of the environment of reference on the outcome of the analysis, are also discussed.

An updated generic architecture describingcompliance in Agri-Food Supply Chains : (D1.2.3)
Kruize, J.W. ; Robbemond, R.M. ; Verwaart, T. - \ 2016
Wageningen : LEI Wageningen UR (Report / LEI Wageningen UR 2016-061) - ISBN 9789462578289 - 21 p.
agro-industrial chains - food chains - food supply - computer software - efficiency - business economics - agro-industriële ketens - voedselketens - voedselvoorziening - efficiëntie - bedrijfseconomie
In this report a generic architecture is presented comprising an inventory of the most important actors, roles, processes and information that are relevant in the processes of standardisation, certification and compliance in Agri-Food Supply Chains. This architecture becomes part of an architectural framework. The architectural framework aims to reduce the paper -based administration by improving digitalisation of compliance processes and to enable a more efficient and effective data exchange in the field of compliance.
Natural genetic variation for regulation of photosynthesis response to light in Arabidopsis thaliana
Rooijen, R. van - \ 2016
University. Promotor(en): Maarten Koornneef, co-promotor(en): Mark Aarts; Jeremy Harbinson. - Wageningen : Wageningen University - ISBN 9789462578203 - 235 p.
arabidopsis thaliana - photosynthesis - genetic variation - light - efficiency - fotosynthese - genetische variatie - licht - efficiëntie

The efficiency of photosynthesis results from the composition and organization of the plant’s internal structural components as well as the capability of response to environmental fluctuations. This thesis aims at identifying the genetic loci that are regulating the (sub-) processes in photosynthetic acclimation to increased irradiance levels, in order to obtain the genetic information useful to breed for photosynthetic performance. It uses genome wide association studies (GWAS) to reveal which genetic loci are being exploited in nature for keeping good photosynthetic performances in natural conditions. Phenotypic variation among natural accessions in photosynthetic light use efficiency response to increased growth irradiance is related to its variation in genetics in order to identify the associated genetic loci. In Chapter 2 is described which light environment reveals most natural variation in photosynthetic performance and for which photosynthetic parameter this is. It shows different Arabidopsis accessions display different photosynthetic responses to various light environments, well relatable to genetic differences. A candidate gene list for the direct response to increased growth irradiance was revealed after performing genome wide association analysis. Chapter 3 elaborates on the genome wide association results by visualizing the dynamics of the associated genetic loci over the time course of the photosynthetic response to increased irradiance. It shows it is possible to simplify the complexity of photosynthetic physiology as well as the genetic analysis in such way to confirm the causal genes underlying the associated loci, by confirming this for the YELLOW SEEDLING 1 (YS1) gene, a gene encoding a Pentatrico-Peptide-Repeat (PPR) protein involved in RNA editing of plastid-encoded genes essential for photosystems I and II. Genetic variation for any trait can be on the transcriptional level or on the functional level. In Chapter 4, the gene regulation in three Arabidopsis accessions with contrasting photosynthesis efficiency responses to increased irradiance is studied. These differences in photosynthesis efficiency are associated to differences in activation extents of heat responsive genes as well as to differences in the presence of a gene activation pathway acting on membrane lipid remodelling, suggested to maintain balanced cellular phosphate concentrations. Chapter 5 confirms the significance of maintaining balanced cellular phosphate concentrations for photosynthesis efficiency responses to increased irradiance. It describes how genome wide association mapping and linkage mapping combine to reveal genetic epistatic interactions between PHOSPHATIDIC ACID PHOPSPHOHYDROLASE 2 (PAH2, phosphate metabolism gene) and ASPARAGINE SYNTHETASE 2 (ASN2, nitrogen metabolism gene), both acting in the delivery of orthophosphate in the chloroplast. In conclusion this thesis contributes new insights into the physiological and molecular pathways underlying photosynthesis responses to increased growth irradiances.

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

Grondstofefficiëntie in de zuivel-, varkensvlees-, aardappel- en suikerketen
Baltussen, W.H.M. ; Dolman, M.A. ; Hoste, R. ; Janssens, S.R.M. ; Reijs, J.W. ; Smit, A.B. - \ 2016
LEI Wageningen UR (Nota / LEI Wageningen UR 2016-013) - 85 p.
agro-industriële ketens - efficiëntie - duurzaamheid (sustainability) - melk - varkensvlees - aardappelen - suiker - productie - nederland - agro-industrial chains - efficiency - sustainability - milk - pigmeat - potatoes - sugar - production - netherlands
In opdracht van het ministerie van Economische Zaken en Topsector Agri & Food heeft LEIWageningen UR de state-of-the-art in kaart gebracht op het gebied van de duurzaamheidsprestatiesvoor vier belangrijke grondstoffen van de aardappel-, suiker-, varkensvlees- en zuivelketen. De viergrondstoffen zijn: land, water, energie en fosfaat. De focus in dit rapport ligt op de kansen enuitdagingen die er zijn op het gebied van efficiënter grondstofgebruik.
De P-benutting door het vee van melkveebedrijven, de impact van minimumwaarden en een tool voor verbetering
Oenema, J. ; Aarts, H.F.M. - \ 2015
Plant Research International (PRI) (PRI Rapport ) - 25 p.
cattle - dairy cattle - cattle feeding - phosphate - excretion - use efficiency - nutrient use efficiency - efficiency - feed conversion efficiency - rundvee - melkvee - rundveevoeding - fosfaat - excretie - gebruiksefficiëntie - nutriëntengebruiksefficiëntie - efficiëntie - voederconversievermogen
In 2013 was de P(benutting van de Nederlandse melkveestapel gemiddeld 30%. De benutting neemt de laatste twee decennia toe met ongeveer 0.25 procentpunt per jaar, met name door het beter presteren van melkkoeien en de afname van het aandeel jongvee. Om onder het plafond van 84.9 miljoen kg fosfaat(excretie te blijven zal een uitbreiding van de melkproductie met 10% gepaard moeten gaan met een verbetering van de benutting van de veestapel met 0.8 procentpunt; een uitbreiding met 20% of 30% verlangt een verbetering van respectievelijk 2.7 procentpunt en 4.5 procentpunt. Bij indeling van bedrijven in klassen, naar grondsoort en intensiteit (melk/ha), blijkt dat de 10% best scorende bedrijven een benutting realiseren die 5.4 tot 7.6 procentpunt hoger is dan die van de 10% slechts scorende. Als de 10%, 20% of 30% slechts scorende bedrijven gedwongen worden de minimum prestatie te realiseren van de resterende 90%, 80% of 70% leidt dit per stap tot een verbetering van 0.2 procentpunt; bij 30% dus tot 0.6 procentpunt. Besproken wordt de opzet van een tool waarmee de veehouder wordt geholpen de P(benutting te verbeteren.
Accuracy of sampling during mushroom cultivation
Baars, J.J.P. ; Hendrickx, P.M. ; Sonnenberg, A.S.M. - \ 2015
Wageningen : Wageningen UR (PPO/PRI report 2015-5) - 33 p.
mushrooms - edible fungi - cropping systems - sampling - agaricus bisporus - mushroom compost - efficiency - dry matter - crop yield - postharvest quality - paddestoelen - eetbare paddestoelen - teeltsystemen - bemonsteren - champignonmest - efficiëntie - droge stof - gewasopbrengst - kwaliteit na de oogst
Experiments described in this report were performed to increase the accuracy of the analysis of the biological efficiency of Agaricus bisporus strains. Biological efficiency is a measure of the efficiency with which the mushroom strains use dry matter in the compost to produce mushrooms (expressed as dry matter produced).
Markt rijp voor betaalbaar kasdek met hoge isolatiewaarde en lichttransmissie : het Nieuwe Telen nog energiezuiniger maken
Rodenburg, J. ; Kempkes, F.L.K. - \ 2015
Onder Glas 12 (2015)6/7. - p. 34 - 35.
glastuinbouw - beglazing - bekleding, bouw - isolatie - transmissie - schermen - efficiëntie - folie - energiebesparing - lichtdoorlating - kastechniek - greenhouse horticulture - glazing - cladding - isolation - transmission - blinds - efficiency - foil - energy saving - light transmission - greenhouse technology
Precies een jaar geleden startte Wageningen UR Glastuinbouw en een consortium van bedrijven met de bouw van een nieuwe, energiezuinige kas. Sleutelcomponent is een ventileerbaar spouwdek dat bestaat uit helder glas waaronder een duurzaam diffuus folie is aangebracht. Dit najaar maken betrokkenen de balans op, maar nu al lijkt de innovatie een aanwinst voor Het Nieuwe Telen. Het systeem oogt professioneel en bezoekers reageren positief.
Perspectives on the distribution of fresh food in emerging metropolises: the cases of Mexico City and Cairo
Waldhauer, N. ; Burgh, M. van der; Vorst, J.G.A.J. van der; Bing, X. ; Scheer, F.P. - \ 2015
Wageningen : Wageningen UR - Food & Biobased Research (Report / Wageningen UR Food &amp; Biobased Research 1529) - ISBN 9789462573642 - 56
voedsel - distributie - voedseldistributieprogramma's - ketenmanagement - voedselketens - logistiek - efficiëntie - stedelijke gebieden - mexico - voedselzekerheid - voedselkwaliteit - voedselverspilling - duurzaamheid (sustainability) - food - distribution - food distribution programs - supply chain management - food chains - logistics - efficiency - urban areas - food security - food quality - food wastage - sustainability
The report consists of four main chapters. In chapter 2 a theoretical framework of urban food distribution is developed based on earlier projects, a literature study and interviews. This framework underlines the main elements of urban food distribution and serves as a theoretical outline for the following case studies and recommendations for improvement. Chapter 3 describes the current situation of fresh food distribution in the two chosen case studies Mexico City and Cairo using the framework of chapter 2 as a reference. Chapter 4 presents the conclusions from the case studies comparing the current situation of the respective urban fresh food distribution networks, assessing the performance of the system and stating the major challenges in both cities. Recommendations for intervention are given in chapter 5 taking into account the conclusions from the case studies, urban distribution initiatives and projects in Western European cities and expert interviews. Chapter 6 gives an outlook into further research.
Voorsorteren op quotumloos tijdperk
Doornewaard, G.J. - \ 2015
Nieuwsbrief Koeien & Kansen (2015)41. - p. 2 - 2.
melkveehouderij - agrarische bedrijfsvoering - melkproductie - kosten per eenheid - optimalisatie - efficiëntie - melkproductiekosten - melkprijzen - dairy farming - farm management - milk production - unit costs - optimization - efficiency - milk production costs - milk prices
Frank en Ilona Post produceren in Nieuweroord (Drenthe) met 135 koeien bijna 1,2 mln. kg melk op zo’n 44 ha cultuurgrond. Het bedrijf is met ruim 27.000 kg melk per ha behoorlijk intensief. De afgelopen jaren was één van de doelstellingen van de maatschap om de kosten en de financiering per kg melk te verlagen.
Tunnels for toads = Hoe effectief zijn paddentunnels?
Ottburg, F.G.W.A. ; Grift, E.A. van der - \ 2015
Alterra, Wageningen-UR
padden - universitair onderzoek - migratie - habitatverbindingszones - monitoring - efficiëntie - diergedrag - wildpassages - toads - university research - migration - habitat corridors - efficiency - animal behaviour - wildlife passages
Het aanleggen van paddentunnels onder een weg helpt padden bij het oversteken van anders dodelijke wegen. Maar als je wilt weten hoe effectief ze zijn, moet je niet alleen kijken hoeveel dieren de tunnels gebruiken, maar ook hoeveel dieren dat niet doen. Fabrice Ottburg en Edgar van der Grift leggen het belang van hun onderzoek uit in een filmpje.
Waterbesparing door slimme en betaalbare sensor
Balendonck, J. - \ 2015
Kas techniek 2015 (2015)april. - p. 34 - 37.
teelt onder bescherming - cultuurmethoden - kunststoftunnels - irrigatie - sensors - instrumenten (meters) - waterbehoefte - vochtmeters - watergebruik - efficiëntie - watergebruiksrendement - irrigatiesystemen - protected cultivation - cultural methods - plastic tunnels - irrigation - instruments - water requirements - moisture meters - water use - efficiency - water use efficiency - irrigation systems
Onderzoekers van Wageningen UR Glastuinbouw hebben in het kader van een Partners voor Water-project laten zien dat Turkse telers met behulp van de AquaTag veel efficiënter kunnen irrigeren. Sturen op vochtsensoren is niet nieuw, maar beschikbare sensoren zijn relatief duur en meten alleen lokaal, terwijl het vochtgehalte sterk kan variëren binnen een kraanvak. Met de AquaTag is nu een goedkope en slimme oplossing voor handen.
Robuuste systemen in de glastuinbouw
Hemming, S. - \ 2015
Kas techniek 2015 (2015)april. - p. 8 - 9.
glastuinbouw - kastechniek - teeltsystemen - optimalisatiemethoden - efficiëntie - duurzame ontwikkeling - ontwerp - innovaties - technische vooruitgang - greenhouse horticulture - greenhouse technology - cropping systems - optimization methods - efficiency - sustainable development - design - innovations - technical progress
Het ontwerpen van weerbare kasproductiesystemen is een uitdaging voor de toekomst. Hierbij is het van belang te komen tot aan de ene kant teeltsystemen voor industriële productie van producten en aan de andere kant een zo duurzaam mogelijke productie om aan de hoge eisen van consumenten te voldoen.
Tomaten belichten met minder elektriciteit
Dieleman, J.A. ; Janse, J. ; Gelder, A. de; Kempkes, F.L.K. ; Visser, P.H.B. de; Lagas, P. ; Meinen, E. ; Warmenhoven, M.G. ; Elings, A. - \ 2015
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1338) - 76
glastuinbouw - cultuurmethoden - tomaten - solanum lycopersicum - belichting - led lampen - energiegebruik - efficiëntie - elektriciteit - reductie - gewasproductie - greenhouse horticulture - cultural methods - tomatoes - illumination - led lamps - energy consumption - efficiency - electricity - reduction - crop production
Over the last 10 years, the use of electricity for assimilation lighting has increased considerably. It is now an important part of the energy use of the horticultural sector. To reverse this trend, in the lighting season 2013/2014, we conducted a trial with the aim to reduce the electricity use in a lighted tomato crop by 35% while maintaining production levels. Two treatments were applied: (1) Reference cultivation: clear glass and lighting by 50% HPS lamps and 50% LED intermittent lighting (210 µmol/m2/s), (2) energy efficient cultivation: diffuse greenhouse cover and lighting by 50% LED top lighting and 50% intermittent LED lighting (210 µmol/m2/s). In the energy efficient cultivation, 37% less electricity was used in the period October - May. However, energy use for heating in this treatment was higher to compensate for the lack of radiative heat. The light sum the plants received (sunlight + artificial lighting) was 6% lower in the energy efficient cultivation compared to the reference cultivation due to the lower number of lighting hours. However, the production difference was only 0.3 kg/m2, less than 1%! Detailed plant measurements showed hardly any differences between the treatments in light interception, light absorption by the leaves, photosynthesis and the production and distribution of assimilates. The analysis of the crop growth model showed that the effect of the lower number of lighting hours in the energy efficient cultivation was fully compensated by the positive effects of the diffuse greenhouse cover which has a higher light transmission.
Robotica toepassingen in Food & Flowers
Pekkeriet, E.J. - \ 2014
Wageningen UR
tuinbouw - glastuinbouw - strategisch management - gewasproductie - robots - automatisering - automatische regeling - innovaties - sensors - afstandssensoren - efficiëntie - nuttig gebruik - horticulture - greenhouse horticulture - strategic management - crop production - automation - automatic control - innovations - remote sensors - efficiency - utilization
Erik Pekkeriet is senior projectmanager Vision & Robotics bij Wageningen UR Glastuinbouw. Hij leidt projecten op het gebied van vision & robotics voor de EU en Nederlandse overheid en is betrokken bij veel robotiseringsprojecten met het tuinbouwbedrijfsleven. Hij geeft zijn visie tijdens de themabijeenkomst
DaglichtKas maakt ambities waar
Zwart, H.F. de - \ 2014
TuinbouwTV
kastechniek - glastuinbouw - potplanten - phalaenopsis - daglicht - duurzame energie - collectoren - schermen - efficiëntie - technieken - energiebesparing - beglazing - greenhouse technology - greenhouse horticulture - pot plants - daylight - sustainable energy - collectors - blinds - efficiency - techniques - energy saving - glazing
Bij Ter Laak Orchids in Wateringen werd dit jaar de eerste DaglichtKas gebouwd. Feije de Zwart van Wageningen UR Glastuinbouw, Hans van Tilborgh van Technokas en John Barendse van Ter Laak Orchids vertellen in deze video over de ervaringen en resultaten in de eerste maanden.
Nieuwe kas met groot potentieel in energiebesparing
Kempkes, F. - \ 2014
Kas techniek 2014 (2014)9. - p. 32 - 35.
glastuinbouw - beglazing - isolatie (insulation) - isolatiematerialen - energiebehoud - kunststoffilm - efficiëntie - landbouwkundig onderzoek - kastechniek - greenhouse horticulture - glazing - insulation - insulating materials - energy conservation - plastic film - efficiency - agricultural research - greenhouse technology
Beter isoleren van de kas vormt een belangrijk onderdeel binnen Het Nieuwe Telen. Wordt dit bereikt door toepassing van meerdere schermen, dan kan dit in de winter ten koste gaan van de toch al beperkte hoeveel heid licht. Gebruik van isolatieglas is een andere richting die al in de praktijk wordt toegepast. Maar er is een goedkoper alternatief, namelijk de combinatie van glas en een hoog waardige film. Het kasconcept ‘2SaveEnergy’ brengt die optie in praktijk.
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