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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    Exploring opportunities for rural livelihoods and food security in Central Mozambique
    Leonardo, Wilson José - \ 2017
    Wageningen University. Promotor(en): K.E. Giller, co-promotor(en): G.W.J. van de Ven; H.M.J. Udo. - Wageningen : Wageningen University - ISBN 9789463431651 - 183
    agricultural production systems - food security - crop production - livelihoods - small farms - biofuels - farming systems - models - intensification - mozambique - agrarische productiesystemen - voedselzekerheid - gewasproductie - middelen van bestaan - kleine landbouwbedrijven - biobrandstoffen - bedrijfssystemen - modellen - intensivering - mozambique

    Growing awareness of widespread hunger and poverty in many countries in the SSA is spurring a focus on productivity increase in smallholder farming systems. The rationale is that with current production systems many SSA countries are not keeping pace with population growth and changing of peoples’ lifestyles. To respond to this challenge the Government of Mozambique developed its Strategic Plan for Agricultural Development (PEDSA) aiming to improve agricultural productivity of the majority of smallholder farmers who depend on agriculture for their livelihoods. Smallholder farmers are diverse in terms of resources and aspirations. The main objectives of this study are first to understand the diversity among maize-based smallholder farms and their current constraints in improving agricultural productivity in the Manica Plateau, Central Mozambique, and second, building on that understanding to explore options for biomass production either for food, cash or biofuel at farm level and contributions to maize availability in the region. The study was conducted in the Dombe and Zembe Administrative Posts. Farmers in the two posts cultivate both food and cash crops using the same resources, however, distances to the urban market differ, with Zembe close and Dombe far away from the markets. In addition, the agroecological conditions for crop production are more favourable in Dombe compared with Zembe. Using farm surveys, direct observations and on-farm measurements, followed by Principal Components Analysis (PCA) I identified land and labour as the variables that can best explain the variability found among smallholder farms (Chapter 2). Based on these variables I categorised farms into four Farm Types (FT): FT1. Large farms (4.4 ha in Dombe and 2.2 ha in Zembe), hiring in labour; FT2. Intermediate sized farms (1.9-1.2 ha), hiring in and out labour; FT3a. Small farms (1.1-0.9 ha), sharing labour; and FT3b. Small farms (1.0-0.7 ha), hiring out labour. The maize yield and maize labour productivities were higher on large farms (2.3 t ha-1 in Dombe and 2.0 t ha-1 in Zembe; 2.5×10-3 t h-1 in Dombe and 2.6 ×10-3 t h-1 in Zembe) compared with small farms (1.5 t ha-1 in Dombe and 1.1 t ha-1 in Zembe; 1.4×10-3 t h-1 in Dombe and 0.9×10-3 t h-1 in Zembe). The hiring in labour from small farms allowed large farms to timely weed their fields. Small farms were resource constrained and hired out labour (mutrakita) for cash or food to the detriment of weeding their own fields, resulting in poor crop yields. Excessive alcohol consumption by small farms also raised concerns on labour quality. Chapter 3 explored options aiming at addressing farmers’ objectives of being maize self-sufficient and increased gross margin and the contribution to national objective of producing food. A bio-economic farm model was used to investigate two pathways to increase agricultural production: (i) extensification, expanding the current cultivated area; and (ii) intensification, increasing input use and output per unit of land.

    In the extensification pathway I considered the use of animal traction, herbicides and cultivators to save labour, whereas in the intensification pathway I explored the use improved varieties of maize, sesame, sunflower, pigeonpea and fertilizers. I focused on the large farms and the small farms hiring out labour as they represent both sides of the spectrum. The simulated results showed that combining labour and labour saving technologies substantially increased both gross margin and maize yields of large and small farms in both posts. Minor trade-offs is observed on large farms between the two goals whereas for small farms we see synergies between the goals. We concluded that prospects for increasing gross margin and food production are much better for large farms in Dombe compared with other farms. In Dombe, the maximum gross margin of large farms was 7530 $ y-1 per farm and maximum maize sales of 30.4 t y-1 per farm. In Zembe, the maximum gross margin of large farms (2410 $ y-1 per farm) and maximum maize sales (9.5 t y-1 per farm) were comparable to small farms in Dombe. I further assessed the impact of two biofuel investments (jatropha plantation and sunflower outgrower schemes) on farm level food security (food availability, access to food, stability of food, utilization of food). The results showed positive impact on small farms from employment on a jatropha plantation by increasing access to food and no impacts on intermediate and large farms. Impacts on food security from the sunflower outgrower scheme were minor which may be explained by the poor yields.

    The need to link smallholder farmers to markets has been increasingly recognized as important strategy to promote rural development and poverty reduction. I developed an analytical framework, the Windmill Approach that looked at decision making at farm level to grow certain crops and at transaction strategies (Chapter 5). Through this framework I showed that a farmer decision to participate in a particular (new) value chain is determined by (a) the suitability of the new crop in the farm system (including the adaptability of the current farm system), and (b) the farmer’s experience with selling in various value chains. This has major policy implications as it highlights that to support smallholder farmers access to markets a holistic approach is needed that combines farming systems analysis and transaction cost theory.

    In order to explore the opportunities for smallholder development there is need to understand the diversity of farms and farmers’ social and economic context. For large farms, in Central Mozambique farms with on average 2-4 ha of land, opportunities to improve their livelihoods through crop production can follow two pathways: intensification and extensification. Smallholders continue to produce staple food crops even when working on a plantation or participating in outgrower schemes. For small farms, off-farm opportunities such as those in a biofuel plantation are the best options to improve their livelihoods.

    Co-creation in the practice, science and movement of agroecology
    Milgroom, J. ; Bruil, Janneke ; Leeuwis, C. - \ 2016
    Farming Matters 32 (2016)1. - ISSN 2210-6499 - p. 6 - 9.
    agroecosystems - sustainability - family farms - farmers' knowledge - knowledge transfer - agricultural production systems - food production - lifelong learning - agro-ecosystemen - duurzaamheid (sustainability) - familiebedrijven, landbouw - kennis van boeren - kennisoverdracht - agrarische productiesystemen - voedselproductie - levenslang leren
    Knowledge building is central to agroecology rooted in family farming. But why?
    What type of knowledge, and whose knowledge is mobilised? This issue of
    Farming Matters explores what we really mean by co-creation of knowledge in
    agroecology, why it is so essential for today’s challenges, and how it takes place
    around the world.
    Country Report for The State of the World’s Biodiversity for Food and Agriculture – The Netherlands : CGN Report 34
    Brink, M. - \ 2015
    biodiversity - food and agriculture organization - netherlands - food production - government policy - animal genetic resources - genetic resources - plant genetic resources - ecosystems - agricultural production systems - biodiversiteit - voedsel- en landbouworganisatie - nederland - voedselproductie - overheidsbeleid - genetische bronnen van diersoorten - genetische bronnen - genetische bronnen van plantensoorten - ecosystemen - agrarische productiesystemen
    The Netherlands Country Report for The State of the World’s Biodiversity for Food and Agriculture forms, together with country reports from other countries, thematic studies, reports from international organizations and inputs from other relevant stakeholders, the basis for the report on the State of the World’s Biodiversity for Food and Agriculture (SoWBFA report). The structure of the Country report follows the FAO’s guidelines, to provide baseline information, highlight knowledge gaps and to facilitate the regional and global synthesis of the information from different countries. The report focuses on developments in the area of Biodiversity for Food and Agriculture (BFA) observed in the last 10 years.
    Verse groenten produceren in de woestijn
    Campen, J.B. - \ 2015
    Kas techniek 2015 (2015)oktober. - p. 16 - 18.
    tuinbouw - glastuinbouw - kastechniek - groenteteelt - midden-oosten - onderzoeksprojecten - voedselproductie - agrarische productiesystemen - teelt onder bescherming - waterbeschikbaarheid - klimaat - horticulture - greenhouse horticulture - greenhouse technology - vegetable growing - middle east - research projects - food production - agricultural production systems - protected cultivation - water availability - climate
    Voedselzekerheid en voedselveiligheid staan hoog op de agenda in het Midden-Oosten sinds de voedselcrisis in 2007-2008. Voedsel wordt voor een groot deel geïmporteerd uit omliggende landen, maar ook uit Nederland. Vooral in de zomermaanden zijn de prijzen van versproducten in deze landen hoog, omdat er dan weinig in de regio zelf wordt geproduceerd. Vanwege de hoge prijzen en de lage kwaliteit van producten uit omliggende landen zijn er verschillende programma’s gestart om het productiesysteem te verbeteren. Hierbij is ook veel aandacht voor waterbesparing, aangezien water een zeer schaars product is in een groot deel van deze regio.
    Exploring options for improving water and nitrogen use efficiency in crop production systems
    Qin, W. - \ 2015
    Wageningen University. Promotor(en): Oene Oenema, co-promotor(en): C. Hu; Marius Heinen. - Wageningen : Wageningen University - ISBN 9789462575035 - 188
    gewasproductie - agrarische productiesystemen - watergebruiksrendement - stikstof - nutriëntengebruiksefficiëntie - mulchen - fertigatie - crop production - agricultural production systems - water use efficiency - nitrogen - nutrient use efficiency - mulching - fertigation

    Water and nitrogen (N) are two key limiting factors in global crop production. However, the optimization of water and N use is often studied separately, and the interactions between water and N use in crop production are often neglected. Lack of systematic and quantitative understanding of the interactions between water and N use may lead to misleading and/or biased recommendations. The main objective of this thesis research was ‘to increase the understanding of interactions between water and N use in crop production’. The specific objectives were (i) to analyse water and N use and their interactions in crop yields and in water and N use efficiencies (WUE and NUE), and (ii) to explore options for increasing crop yields and water and N use efficiencies simultaneously.

    In this thesis, I combined the use of literature review and meta-analysis, long-term field experiments and soil-crop modelling to quantify relationships between water and N use and their interactions in crop yields, WUE and NUE, and to explore options for improving the productivity and sustainability of two important and contrasting crop systems (i.e., annual cereal and perennial orange systems).

    In arid and semi-arid regions, such as the Loess Plateau, I found that the water loss via soil evaporation was large as much as 60 to 70% of total rainfall and thereby significantly limited wheat yields. Soil mulching can effectively reduce soil evaporation thereby increasing crop yields by up to 60%. In sub-humid regions, the productivity and sustainability of rainfed wheat-soybean rotation systems can be constrained by soil fertility and other factors besides water and nutrient management. Fertilization and soil organic amendments greatly increased wheat yield and WUE, but decreased NUE.

    In advanced fertigated orange production systems, a main challenge is to optimize water and N use for optimal yield while minimizing environmental pollution. Fertigation provides opportunities to simultaneously optimize water and N use in orange production systems. Optimization of water and N supply is, however, complicated in practice due to erratic and uncontrollable rainfall, which may lead to large incidental losses. Improving water and N input can significantly and simultaneously increase orange yield, WUE and NUE (by 20, 30 and 40% respectively). Importantly, even with optimal water and N input levels, fractionation (split) strategies can significantly increase orange yield and reduce N losses.

    In conclusion, rainfed cereal crop yields, WUE and NUE in dryland agriculture can be increased by up to 60%, with currently available knowledge and soil mulching techniques. In many regions in the world, there is still a large gap between observed farm yield and attainable yield by best management. Given large potentials in low-performing agricultural systems, investments in knowledge and education, infrastructures and subsidies should also be prioritized for these regions. Potentially, this will significantly contribute to local and global food security at large.

    Dossier Functionele Agrobiodiversiteit
    Alebeek, F.A.N. van - \ 2015
    Groen Kennisnet
    agrobiodiversiteit - agrarische productiesystemen - plagenbestrijding - biologische bestrijding - agrarisch natuurbeheer - gewasbescherming - bodemvruchtbaarheid - agro-biodiversity - agricultural production systems - pest control - biological control - agri-environment schemes - plant protection - soil fertility
    De diversiteit aan soorten organismen als planten, dieren, micro-organismen – in een woord biodiversiteit – is een samenhangend geheel. De soorten binnen een systeem kunnen elkaar op verschillende manieren beïnvloeden. Regenwormen en micro-organismen kunnen de bodemstructuur verbeteren, bijen zorgen voor bevruchting van planten en zweefvliegen kunnen de ontwikkeling van luizen onderdrukken.
    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?
    Certifications, child labour and livelihood strategies: an analysis of cocoa production in Ghana
    Owusu-Amankwah, R. - \ 2015
    Wageningen University. Promotor(en): Han Wiskerke; Guido Ruivenkamp, co-promotor(en): Joost Jongerden. - Wageningen : Wageningen University - ISBN 9789462574915 - 348
    cacao - productie - landbouw bedrijven in het klein - gemeenschappen - kinderarbeid - strategieën voor levensonderhoud - certificering - agrarische productiesystemen - ghana - cocoa - production - peasant farming - communities - child labour - livelihood strategies - certification - agricultural production systems - ghana


    There have been various innovative initiatives by global and local actors in response to pressure on cocoa value-chain actors to free cocoa production from child labour (CL) and especially the worst forms of child labour (WFCL) and also to improve the livelihoods of farm families. Analyses of the implementation, implications and the appropriateness of these initiatives in driving change in the cocoa supply chain and improving the labour and income conditions in cocoa farms are limited, however. This study examines initiatives being led by the key actors in the value chain – the governmental initiative of a community-based child labour monitoring (CCLM) system (CCLMS), that led by business actors of third party voluntary cocoa certification (TPVCC), and farmers’ own way of diversifying income – in order to understand current developments in the cocoa value-chain and analyse the dynamics between the local and global actors and the effect of these dynamics for the reorganisation of the cocoa production system in Ghana.

    This thesis employs an interdisciplinary perspective and combines innovation theory with livelihood, social perspectives and other social science tools to empirically investigate the initiatives as they operate at micro-, meso- and macro-levels so as to ascertain their implications for farmers’ livelihoods and children’s social situations. It also reflects scholarly interest in understanding how global-level development interacts with and affects local-level development, and how globalisation shapes and mediates local influences within the cocoa production system.

    Firstly, the CCLMS study (Chapter 3) reveals three kinds of benefits to children: an expanded social network, a reduction in their participation in hazardous work and an improvement in school attendance. The findings show that absenteeism on the part of the pupils in a community with a CCLM intervention is approximately half that of two communities without intervention. In addition, it is observed that although children are involved in hazardous and non-hazardous activities in all the three communities involved in the study, the extent of their involvement in hazardous activities is higher in the communities without intervention.

    Secondly, third party certification (TPC) formulated by the business actors is a key innovation in the cocoa production system of Ghana. The study presented in Chapter 4 shows the potential of TPVCC to mobilise financial, human and social capitals to address gaps and

    dysfunctions and create a win-win situation for all the actors of the value chain. However, sector-wide standards that address sector specific needs taking into consideration the views of chain actors, especially farmers and their socio-cultural context will enhance compliance. This is because global or international standards cannot be imposed but are analysed, contested and adapted by farmers to suit on-the-ground practices. The study also shows the potential of TPVCC to address CL and livelihood issues, but these will yield better results if it is implemented in enhanced socio-economic conditions. Regardless of these positives, the net benefit of certification is unclear due to the difficulty in conducting proper cost-benefit analyses in the absence of proper documentation of farmer-level costs and other factors.

    Thirdly, the findings show that about 70% of farmers are diversifying into other (non-cocoa) farm and non-farm activities using largely indigenous resources, but on a small scale and at subsistence level. This condition means that the goal of farmers to supplement cocoa income and reduce risk is not achieved throughsuch a level of diversification. There is some indication of increasing importance of income and resources from non-farm activities, but income from cocoa continues to determine household income as well as the demand for non- farm goods and investment in the non-farm sector. This study also finds that children are involved in both farm and non-farm activities, which can be classified as hazardous and non- hazardous. Farmers, especially caretakers, producing at subsistence level are likely to use their children to supplement labour needs. Some policy recommendations are made in the areas of economic incentives and multi-stakeholder collaboration to stimulate the sector towards sustainability.

    Climate Smart Agriculture: Synthesis of case studies in Ghana, Kenya and Zimbabwe
    Hengsdijk, H. ; Conijn, J.G. ; Verhagen, A. - \ 2015
    Wageningen : Wageningen UR (Report / Plant Research International 624) - 26
    stadslandbouw - biologische landbouw - duurzame landbouw - metriek stelsel - ghana - kenya - zimbabwe - engelssprekend afrika - agrarische productiesystemen - klimaatadaptatie - voedselveiligheid - urban agriculture - organic farming - sustainable agriculture - metric system - ghana - kenya - zimbabwe - anglophone africa - agricultural production systems - climate adaptation - food safety
    This study contributes to the current debate on climate smart agriculture and development in Africa, specifically in relation to farm size, food security and intensification in rain fed farming areas. Although the different analyses are rough, because of a combination of incomplete knowledge and limited data sets, the results places the prevailing development discussions in the context of CSA: Provides intensification a way out of poverty and contributes intensification to food security under climate change? How affects climate change crop yields and household income? Conflicts intensification with climate mitigation goals? These are some of the questions addressed for diverging case study areas in this study.
    Verdienmodellen voor Natuurinclusieve landbouw. Wat ondernemers al doen, en wat de overheid kan doen om opschaling te bevorderen
    Grin, J. ; Polman, N.B.P. ; Dijkshoorn-Dekker, M.W.C. ; Vogelzang, T.A. - \ 2015
    Den Haag : LEI Wageningen UR (LEI Notitie 2015-044) - 19
    landbouw - agrarisch natuurbeheer - ecosysteemdiensten - agrarische productiesystemen - duurzaamheid (sustainability) - agriculture - agri-environment schemes - ecosystem services - agricultural production systems - sustainability
    De Rijksnatuurvisie 2014 breekt een lans voor natuurinclusieve landbouw waarbij veel nadruk ligt op de rol van markt en maatschappij. Zulke landbouw behelst wat de nota noemt ‘natuurcombinaties’ waarbij natuur en economische activiteiten met elkaar vervlochten zijn. Een natuurinclusieve landbouw heeft een wezenlijk andere oriëntatie dan gangbare landbouw. In dit essay gaan we in op de voorwaarden waaronder natuurinclusieve verdienmodellen op middellange termijn op grote schaal kunnen worden gerealiseerd. Dit wordt uiteengezet op basis van de ervaringen van koplopers, die al langer aan natuurinclusieve landbouw doen.
    DaVinc³i: sierteeltlogistiek in een dynamische eeuw : van onderbuik naar onderbouwing
    Vorst, J.G.A.J. van der; Ossevoort, R.S. - \ 2015
    DaVinc³i - 46
    sierteelt - logistiek - ketenmanagement - agro-industriële ketens - informatietechnologie - internationale handel - strategisch management - agrarische productiesystemen - landbouwkundig onderzoek - telecommunicatie - elektronische handel - ornamental horticulture - logistics - supply chain management - agro-industrial chains - information technology - international trade - strategic management - agricultural production systems - agricultural research - telecommunications - electronic commerce
    In het DaVinc³i (Dutch Agricultural Virtualized International Network with Consolidation, Coordination, Collaboration and Information availability) onderzoek deden drie Nederlandse universiteiten en een groot aantal bedrijven strategisch onderzoek naar deelgebieden van de sierteeltlogistiek. Die deelgebieden zijn: samenwerking/ businessmodellen, logistieke netwerken, retourlogistiek/plannen en ICT in de sector. Bij veel bedrijven is concreet en strategisch onderzoek gedaan op basis van onderzoeksvragen op bedrijfsniveau. Dit boekje verhaalt, in een aantal interviews, eerst over de algemene strategische onderzoeken en de daaruit voortvloeiende scenario’s. Daarna komt de bedrijfspraktijk aan de orde. De volgende vragen kwamen hierbij aan de orde: Met welke logistieke ketens en afzetketens krijgt de sierteeltsector in de toekomst te maken? Welke functies en processen zijn aan die ketens verbonden? Waar kun je die functies geografisch gezien het best uitoefenen? Hoe ondersteun je dat optimaal met ICT-toepassingen en businessmodellen? Wat betekent dit alles voor de sierteeltlogistiek?
    Improving radiation use efficiency in greenhouse production systems
    Li, Tao - \ 2015
    Wageningen University. Promotor(en): Leo Marcelis, co-promotor(en): Ep Heuvelink. - Wageningen : Wageningen University - ISBN 9789462572577 - 156
    glastuinbouw - kassen - gewasfysiologie - agrarische productiesystemen - gewasproductie - stralingsbenuttigingsefficiëntie - straling - fotosynthese - licht - gebruiksefficiëntie - greenhouse horticulture - greenhouses - crop physiology - agricultural production systems - crop production - radiation use efficiency - radiation - photosynthesis - light - use efficiency


    A large increase in agricultural production is needed to feed the increasing world population with their increasing demand per capita. However, growing competition for arable land, water, energy, and the degradation of the environment impose challenges to improve crop production. Hence agricultural production efficiency needs to increase. Greenhouses provide the possibility to create optimal growth conditions for crops, thereby improving production and product quality. Light is the driving force for plant photosynthesis and in greenhouse horticulture, light is often the most limiting factor for plant growth. Therefore, improving radiation use efficiency (RUE) in greenhouse production systems is imperative in order to improve plant growth and production. The objective of this thesis is to obtain insight in improving RUE in greenhouse production systems through better understanding of crop physiology. Three aspects related to RUE have been studied in this thesis, 1) improving light distribution in the crop canopy; 2) allowing more light in the greenhouse during summer; and 3) balancing the source and sink strength during plant growth.

    Light is heterogeneously distributed in the crop canopy. Due to the saturating response of leaf photosynthesis rate to light, a more homogeneous light distribution in the canopy will result in a higher crop photosynthesis. In Chapter 2, the effect of diffuse glass on spatial light distribution in a fully developed tomato canopy and its direct and indirect effects on crop photosynthesis were explored. Diffuse glass, which transforms a portion of direct solar light into diffuse light without influencing the light transmissivity of the glass, was applied as greenhouse cover. Under diffuse glass cover, light was more evenly distributed (in both horizontal and vertical direction) within the canopy compared with plants grown under conventional clear glass cover. Besides a more uniform light distribution, diffuse glass also resulted in higher leaf photosynthetic capacity in the middle of the crop canopy and in a higher leaf area index (LAI). The higher leaf photosynthetic capacity was positively correlated with a higher leaf total nitrogen and chlorophyll content. Moreover, lower leaf temperature and less photo-inhibition of top canopy leaves were observed under diffuse glass cover when global radiation was high. Total crop photosynthesis between 1st April and 1st October was enhanced by 7.2 % under diffuse glass. This enhancement mainly resulted from four factors (in order of decreasing importance): a more homogeneous horizontal light distribution, a higher leaf photosynthetic capacity, a more uniform vertical light distribution and a higher LAI.

    In summer growers of shade tolerant pot-plants often apply shading screens in the greenhouse or white wash on the greenhouse cover in order to avoid leaf or flower damage caused by high light. Shading carries a penalty on potential crop growth which is positively related to the amount of light that can be captured. Considering the advantageous properties of diffuse glass cover, i.e. a more homogeneous light distribution, a lower leaf temperature and less photo-inhibition when global radiation is high, in Chapter 3 we tested the feasibility of allowing more light (i.e. less shading) via diffuse glass cover for cultivation of shade tolerant pot-plants during summer. Two Anthurium andreanum cultivars (Pink Champion and Royal Champion) were grown in 3 greenhouse compartments. Under similar DLI [7.5 mol m-2 d-1 PAR (photosynthetic active radiation)], diffuse glass cover resulted in 8 % higher crop RUE (i.e. dry mass production per unit intercepted light) in ‘Royal Champion’ compared with clear glass cover treatment, which consequently resulted in higher total biomass production. This effect was not observed in ‘Pink Champion’. Under diffuse glass cover, high DLI (10 mol m-2 d-1 PAR) resulted in 20-23 % higher total biomass production in both cultivars compared with low DLI (7.5 mol m-2 d-1 PAR), this mainly resulted from the higher cumulative intercepted light. No flower or leaf damage was observed in these treatments. High DLI even resulted in more compact plants as indicated by a higher ratio of aboveground fresh mass to plant height.

    In Chapter 4, we addressed a question resulting from Chapter 3, i.e. why the stimulating effect of diffuse light on crop RUE in anthurium pot-plants is cultivar specific? We excluded the fraction of canopy light interception and steady-state leaf photosynthesis as potential explanations, and explained it from instantaneous leaf photosynthesis which closely correlates with the temporal light distribution. Diffuse glass cover smoothed the variation of temporal light distribution at a given point on a leaf during a clear day, which consequently resulted in less temporal variation of stomatal conductance in ‘Royal Champion’ which had stomata showing a fast-response to the variation in light intensity. As stomata are the gateway for CO2 uptake, less variation in stomatal conductance imposed less limitation for leaf photosynthesis under diffuse glass cover, thereby resulting in a higher crop RUE. For ‘Pink Champion’, however, stomata were less responding to variations in light intensity. Therefore, stomata imposed only a marginal limitation on leaf photosynthesis even under clear glass cover where the temporal incident light intensity varied substantially due to the shadow cast by the greenhouse construction parts and equipment.

    Application of supplementary assimilation light in greenhouses is rapidly increasing. The beneficial effect of supplementary assimilation light is determined by the balance between assimilate production in source leaves and the overall capacity of the plant to use these assimilates. Therefore, it is important to identify the source-sink balance during plant growth. In Chapter 5, three tomato cultivars with different potential fruit size [‘Komeett’ (large size); ‘Capricia’ (medium size); ‘Sunstream’ (small size, cherry tomato)] were grown under commercial crop management. We estimated the source-sink ratio from the early growth stage to fully fruiting stage through experimentation and model simulation. Carbohydrate content of leaves and stems were periodically determined. Tomato plants showed a period of sink limitation (‘Komeett’ and ‘Capricia’) or came close to sink limitation (‘Sunstream’) during the early growth stage under ample natural irradiance (early September) as indicated by a source-sink ratio higher than or close to 1. Fruiting tomato plants were source-limited as indicated by an extremely low source-sink ratio (average source-sink ratio from 50 days after planting onwards was 0.17, 0.22 and 0.33 for ‘Komeett’, ‘Capricia’ and ‘Sunstream’, respectively). During the fully fruiting stage, the source-sink ratio was negatively correlated with the potential fruit size when commercial fruit load was maintained. Carbohydrate content in tomato stems and leaves increased linearly with plant source-sink ratio.

    The experiments and results described in this thesis provide insights for improving RUE in greenhouse production systems. The main achievements and limitations as well as practical applications are discussed in Chapter 6.

    Animal welfare decisions in Dutch poultry and pig farms
    Gocsik, E. - \ 2014
    Wageningen University. Promotor(en): Alfons Oude Lansink, co-promotor(en): Helmut Saatkamp; Ivo van der Lans. - Wageningen : Wageningen University - ISBN 9789462571624 - 261
    dierenwelzijn - dierlijke productie - pluimvee - varkens - investering - economie - varkenshouderij - pluimveehouderij - huisvesting, dieren - agrarische productiesystemen - vleeskuikens - hennen - animal welfare - animal production - poultry - pigs - investment - economics - pig farming - poultry farming - animal housing - agricultural production systems - broilers - hens


    The minimum level of animal welfare (AW) is guaranteed by EU and national legislation in most European countries. Within the current international economic and political environment further improvements in the welfare of farm animals predominantly rely on market initiatives. Market initiatives set requirements in terms of AW that exceed the legal minimum standards. Participation in a particular market initiative is a voluntary choice of the farmer. The overall objective of this dissertation was to analyze the factors that determine farmers’ decision-making with regard to the implementation of AW standards, and to identify barriers to the adoption of above-legal AW standards at farm level. In this dissertation farmers’ decision-making is conceptualized as a process in which farmers trade off financial and non-financial goals. Financial goals relate to monetary aspects, whereas non-financial goals appeals to farmers’ intrinsic motivation to improve AW. This dissertation suggests that broiler and fattening pig farmers do not have a strong intrinsic motivation to switch to a production system that provides higher level of AW than the minimum legal requirements. In this respect, at farm level certain financial preconditions have to be met to enable farmers to adopt higher AW standards. More specifically, farmers require a price premium that is at least sufficient to cover extra costs as a result of higher animal welfare standards. Furthermore, it is important to manage the (perceived) uncertainty of the market and price premiums. These imply that middle-market segment could be attractive for farmers due to its high cost-efficiency, i.e., realize the highest relative increase in AW at the lowest costs, which is also in the best interest of other stakeholders in the supply chain. Furthermore as switching to a middle-market system primarily affects variable costs farmers are given the flexibility to revert to the conventional system if their expectations are not met. Middle-market segment products, as they improve on many production attributes related to AW, may also offer alternatives for consumers that take many attributes into account to form an opinion of the animal friendliness of a production system. In the light of the foregoing, further development of the middle-market segment appears to be a reasonable direction in improving AW. In order to facilitate the further development of the middle-market segment a high involvement of all stakeholders in the supply chain, i.e., slaughterhouses, processors, retail, NGOs, and the government as well is required.

    Socio-economic impacts and determinants of parasitic weed infestation in rainfed rice systems of sub-Saharan Africa
    N'cho, A.S. - \ 2014
    Wageningen University. Promotor(en): Alfons Oude Lansink, co-promotor(en): Monique Mourits; J. Rodenburg. - Wageningen : Wageningen University - ISBN 9789462571266 - 160
    rijst - agrarische productiesystemen - gewasproductie - onkruiden - parasitaire onkruiden - striga hermonthica - striga asiatica - controle - onkruidbestrijding - regenafhankelijke landbouw - economische impact - sociale factoren - besluitvorming - boeren - afrika ten zuiden van de sahara - benin - ivoorkust - tanzania - rice - agricultural production systems - crop production - weeds - parasitic weeds - striga hermonthica - striga asiatica - control - weed control - rainfed agriculture - economic impact - social factors - decision making - farmers - africa south of sahara - benin - cote d'ivoire - tanzania

    Keywords: rice; weed; weed management practices, adoption, impact, parasitic weeds; Rhamphicarpa fistulosa; Striga asiatica; Striga hermonthica, double hurdle model; multivariate probit, productivity, stochastic frontier analysis, data envelopment analysis, directional distance function, sub-Saharan Africa, Benin, Cote d’Ivoire, Tanzania.

    Socio-economic impacts and determinants of parasitic weed infestation in

    rainfed rice systems of sub-Saharan Africa

    Simon A. N’cho


    Rice is an important strategic crop for food security in sub-Saharan Africa. However, its production is constrained by many biotic and abiotic stress. In rainfed rice systems, weeds and particularly parasitic weeds are among the most damaging constraints. The objective of this thesis was to identify factors affecting infestation of rice farms by parasitic weeds and to assess the economic and social impact of parasitic weeds on primary producers of rainfed rice systems in order to provide guidance for decision-making for rice farmers and policymakers aiming at developing strategies for coping with parasitic weeds. To achieve this objective, we first explored biophysical characters of the rice growing environment, farmers’ management practices, and socio-economic characteristics that affect the infestation of rice fields by parasitic weeds (PWs) and farmers’ ability to cope with the problem. A double hurdle model was used to analyses simultaneously the likelihood of occurrence and the severity of infestation of the PW. The findings suggest that farmers can cope with the PW as long as they are aware of the problem provided they have a good access and management capacity of production resources. Next, we examined weed management practices (WMPs) currently available to farmers and how PW infestation affect their choices for specific combinations of WMPs using a multivariate probit model. Findings indicate that farmers are more likely to adopt improved weed management practices or combined more WMPs when their fields are infested by PWs. Species-specific and country-specific approaches and technologies are require to address the PW problem. Then, we assessed the impact of parasitic weeds infestation on farmers’ productivity and examined how this problem and managerial factors prevent farmers from achieving optimal technical efficiency levels using a stochastic frontier analysis (SFA). PWs induce productivity losses ranging from 21% to 50%. Farmers seem to cope with PW through learning from experiencing PW problem. Finally, we estimated weeding labour inefficiencies using a Data Envelopment Analysis (DEA) with directional input distance function and a single truncated bootstrap regression to identify sources of inefficiencies. Results suggest that, farmers can save substantial (58% – 69%) weeding labour without reducing rice production. No evidence was found that the currently used manual weeding modalities were able to manage parasitic weeds efficiently. The main finding of this thesis is that in sub-Saharan Africa, PWs infestation has a negative impact on rainfed rice systems’ productivity and the use of production resources. However, these impacts can be reduced if farmers have a good access to production resources and manage them efficiently.

    Adaptation of livestock systems to climate change: functions of grassland, breeding, health and housing
    Hoving, I.E. ; Stienezen, M.W.J. ; Hiemstra, S.J. ; Dooren, H.J.C. van; Buisonjé, F.E. de - \ 2014
    Wageningen : Wageningen UR Livestock Research (Report / Wageningen UR Livestock Research 793) - 52
    veehouderij - klimaatverandering - klimaatadaptatie - broeikasgassen - mitigatie - landbouw en milieu - landbouwproductie - agrarische productiesystemen - duurzame veehouderij - livestock farming - climatic change - climate adaptation - greenhouse gases - mitigation - agriculture and environment - agricultural production - agricultural production systems - sustainable animal husbandry
    This report presents the available knowledge and relevant research questions related to 1) grassland based livestock production systems and GHG emissions, and 2) adaptation of livestock systems to climate change, to provide information for prioritization research and other actions on adaptation and mitigation. Solutions can be found through the combination of enabling infrastructure for agricultural development and introducing public-private cooperation into research programmes. The provision of veterinary services, financial services, a knowledge infrastructure and governance of land use are essential for maintaining and improving agricultural productivity.
    Producentenorganisaties Anno 2014
    Litjens, M.E.G. - \ 2014
    Tijdschrift voor Agrarisch Recht 74 (2014)4. - ISSN 1874-9674 - p. 139 - 146.
    producentengroepen - organisaties - agrarische productiesystemen - landbouwsector - gemeenschappelijk landbouwbeleid - producer groups - organizations - agricultural production systems - agricultural sector - cap
    Net voor het begin van het nieuwe jaar 2014 is de verordening tot vaststelling van een gemeenschappelijke ordening van de markten voor landbouwproducten gepubliceerd. Deze Verordening (EU) 1308/2013 bevat de regels betreffende producentenorganisaties. Door middel van producentenorganisaties kunnen agrarische producenten hun krachten bundelen. De hervorming van het landbouwbeleid, waar deze verordening uit voortkomt, is gericht op versterking van het juridische raamwerk voor producentenorganisaties. Het doel van dit artikel is om de regels over producentenorganisaties te beschrijven en de versterking van het juridische framework voor het voetlicht te brengen.
    Aalt Dijkhuizen: schone teelt vraagt om vertaling onderzoeksresultaten naar praktijk
    Dijkhuizen, A.A. - \ 2014
    Aardappelwereld 2014 (2014)2. - ISSN 0169-653X - p. 10 - 11.
    aardappelen - akkerbouw - proeven op proefstations - landbouwkundig onderzoek - toegepast onderzoek - onderzoeksinstituten - agrarische productiesystemen - maximum opbrengst - kennisoverdracht - nederland - potatoes - arable farming - station tests - agricultural research - applied research - research institutes - agricultural production systems - maximum yield - knowledge transfer - netherlands
    Onderzoek bij PRI en het PPO-agv besproken naar aanleiding van het thema 'Schone teelt bepaalt de toekomst' van de Aardappeldemodag 2014 te Westmaas
    Local for local in Europees perspectief - Verkennende marktstudie voor de Nederlandse glastuinbouw
    Stokkers, R. - \ 2014
    Den Haag : LEI Wageningen UR - 52
    glastuinbouw - agrarische handel - agrarische productiesystemen - europa - landbouwhervorming - ontwikkelingsplannen - modellen - agrarische bedrijfsplanning - marktverkenningen - aanpassing van de productie - greenhouse horticulture - agricultural trade - agricultural production systems - europe - agrarian reform - development plans - models - farm planning - market surveys - adjustment of production
    Het doel van deze deelstudie is om inzicht te verschaffen in de kansen en bedreigingen van het concept ‘local for local’ op de belangrijkste Europese afzetmarkten en aanknopingspunten te bieden voor Nederlandse producentenorganisaties en handels-bedrijven in de tuinbouw bij het ontwikkelen van nieuwe business modellen gericht op 'local for local'.
    Aalt Dijkhuizen : 'Wetenschap niet verwarren met politiek'
    Dijkhuizen, A.A. - \ 2014
    V-focus 11 (2014)1. - ISSN 1574-1575 - p. 6 - 8.
    agrarisch onderwijs - universiteiten - landbouwkundig onderzoek - bestuur - agrarische productiesystemen - dierenwelzijn - interviews - dierlijke productie - agricultural education - universities - agricultural research - administration - agricultural production systems - animal welfare - interviews - animal production
    Aalt Dijkhuizen baarde in 2012 veel opzien toen hij luid hoorbaar verkondigde dat de agrarische producties omhoog moeten vanwege de wereldwijde voedselbehoefte. Vanuit agrarische kringen ging applaus op, dierenwelzijnsorganisaties hadden felle kritiek. Beide reacties kan Dijkhuizen zich voorstellen. Alleen het onfatsoen waarmee sommige NGO’s en hun sympathisanten reageerden, vindt hij ongehoord. Op 1 maart 2014 stopt Dijkhuizen als voorzitter van de raad van bestuur van Wageningen UR. In dit interview blikt hij terug op twaalf jaar voorzitterschap.
    Laag pathogene aviaire influenza virus infecties op pluimveebedrijven in Nederland
    Goot, J.A. van der; Verhagen, J. ; Gonzales, J. ; Backer, J.A. ; Bongers, J.H. ; Boender, G.J. ; Fouchier, R.A.M. ; Koch, G. - \ 2013
    Tijdschrift voor Diergeneeskunde 138 (2013)6. - ISSN 0040-7453 - p. 24 - 29.
    pluimveehouderij - pluimveeziekten - aviaire influenza - hennen - kippen - ziekte-incidentie - huisvesting, dieren - agrarische productiesystemen - uitloop - risicofactoren - poultry farming - poultry diseases - avian influenza - hens - fowls - disease incidence - animal housing - agricultural production systems - outdoor run - risk factors
    Dit artikel is een samenvatting van het rapport "Laag pathogene aviaire influenza virus iInfecties op pluimveebedrijven in Nederland" (CVI 2012). Dit rapport is geschreven naar aanleiding van vragen van het toenmalige Ministerie van Economische zaken, Landbouw en Innovatie. De vragen die werden gesteld zijn: - hebben pluimveebedrijven met vrije uitloop een grotere kans op introductie van LPAI virus infecties?; - is de kans op introductie gerelateerd aan wilde vogels?; - is er een periode in het jaar waarin het risico op infectie groter is? - kunnen er factoren geidentificeerd worden die de kans op introductie verminderen?
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