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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European mushroom assemblages are darker in cold climates
Krah, Franz Sebastian ; Büntgen, Ulf ; Schaefer, Hanno ; Müller, Jörg ; Andrew, Carrie ; Boddy, Lynne ; Diez, Jeffrey ; Egli, Simon ; Freckleton, Robert ; Gange, Alan C. ; Halvorsen, Rune ; Heegaard, Einar ; Heideroth, Antje ; Heibl, Christoph ; Heilmann-Clausen, Jacob ; Høiland, Klaus ; Kar, Ritwika ; Kauserud, Håvard ; Kirk, Paul M. ; Kuyper, Thomas W. ; Krisai-Greilhuber, Irmgard ; Norden, Jenni ; Papastefanou, Phillip ; Senn-Irlet, Beatrice ; Bässler, Claus - \ 2019
Nature Communications 10 (2019). - ISSN 2041-1723

Thermal melanism theory states that dark-colored ectotherm organisms are at an advantage at low temperature due to increased warming. This theory is generally supported for ectotherm animals, however, the function of colors in the fungal kingdom is largely unknown. Here, we test whether the color lightness of mushroom assemblages is related to climate using a dataset of 3.2 million observations of 3,054 species across Europe. Consistent with the thermal melanism theory, mushroom assemblages are significantly darker in areas with cold climates. We further show differences in color phenotype between fungal lifestyles and a lifestyle differentiated response to seasonality. These results indicate a more complex ecological role of mushroom colors and suggest functions beyond thermal adaption. Because fungi play a crucial role in terrestrial carbon and nutrient cycles, understanding the links between the thermal environment, functional coloration and species’ geographical distributions will be critical in predicting ecosystem responses to global warming.

Exploring options for sustainable intensification through legume integration in different farm types in Eastern Zambia
Timler, C.J. ; Michalscheck, M. ; Alvarez, S. ; Descheemaeker, K.K.E. ; Groot, J.C.J. - \ 2017
In: Sustainable Intensification in Smallholder Agriculture / Oborn, Ingrid, Vanlauwe, Bernard, Philips, Michael, Thomas, Richard, Brooijmans, Willemien, Atta-Krah, Kwesi, Earthscan (Earthscan Food and Agriculture ) - ISBN 9781138668089 - p. 196 - 209.
In Zambia maize is the main staple food crop and, with a share of 52% in the daily calorie intake of the local population, it is critical for ensuring the national food security (FAOSTAT, 2013). Of the total maize consumed in Zambia, smallholder farmers produce 80% in rain-fed systems under low soil fertility, frequent drought and with a limited use of high yielding varieties or inorganic fertiliser (Sitko et al., 2011). In eastern Zambia, the livelihoods of small-scale farmers depend largely on maize-legume mixed systems characterised by low productivity, extreme poverty and environmental degradation (Sitko et al., 2011). Thus, there seems to be a great need for sustainable intensification of these farming systems, for instance through promoting best practices in maize–legume integration. Maize–legume cropping provides protein-rich food for humans, residues for animal feed, composting and soil amendments and nitrogen inputs through symbiotic fixation by the legume. Sustainable intensification of farming systems can take place through changes in resource use and allocation that increase farm productivity while reducing pressure on local ecosystems and safeguarding social relations. According to Pretty et al. (2011), this entails the efficient use of all inputs to produce more outputs while reducing damage to the environment and building a resilient natural capital from which environmental services can be obtained. Sustainable intensification results from the application of technological and socio-economic approaches that may be categorised into genetic, ecological and socio-economic intensification (The Montpellier Panel, 2013).
Integrated systems research in nutrition-sensitive landscapes : A theoretical methodological framework
Groot, Jeroen C.J. ; Kennedy, Gina ; Remans, Roseline ; Estrada-Carmona, Natalia ; Raneri, Jessica ; DeClerck, Fabrice ; Alvarez, Stéphanie ; Mashingaidze, Nester ; Timler, Carl ; Stadler, Minke ; Río Mena, Trinidad del; Horlings, Lummina ; Brouwer, Inge ; Cole, Steven M. ; Descheemaeker, Katrien - \ 2017
In: Sustainable Intensification in Smallholder Agriculture / Oborn, Ingrid, Vanlauwe, Bernard, Phillips, Michael, Thomas, Richard, Atta-Krah, Kwesi, Brooijmans, Willemien, New York : Routledge / Earthscan - ISBN 9781138668089 - p. 259 - 274.
South Asia and sub-Saharan Africa are two regions of the world with the highest concentration of nutritionally vulnerable populations that depend to a large extent on agriculture as an important source of livelihood (Gillespie et al., 2015). The vast majority of farmers in these regions have small landholdings due to land fragmentation (Jayne et al., 2014; Valbuena et al., 2015) and are often constrained in their access to resources and agricultural inputs (Herrero et al., 2010), especially women (e.g., Cole et al., 2015). As a consequence, productivity levels are low, and because income sources are also limited, dependence on surrounding landscapes and ecosystem services is high in terms of safeguarding supplies of clean water, human and animal foods, construction materials and fuel wood. People shape their physical landscapes (Ellis, 2015), influenced by cultures, values and livelihood opportunities (Horlings, 2015). People’s utilization of their physical landscapes is shaped by various conditions such as soil properties, topography, climate and flooding patterns. People’s dependence on their physical landscapes is strong and expected to increase due to climate change, resulting in gradual but persistent changes including adjustments in frequency, timing and severity of anomalies such as droughts and floods (Naylor et al., 2007; Gornall et al., 2010).
Integrated systems research for sustainable intensification of smallholder agriculture
Öborn, Ingrid ; Vanlauwe, Bernard ; Atta-Krah, Kwesi ; Thomas, Richard J. ; Phillips, Michael ; Schut, Marc - \ 2017
In: Sustainable Intensification in Smallholder Agriculture: An Integrated Systems Research Approach / Oborn, Ingrid, Vanlauwe, Bernard, Phillips, Michael, Thomas, Richard, Atta-Krah, Kwesi, Brooijmans, Willemien, Taylor and Francis Inc. - ISBN 9781138668089 - p. 1 - 15.
In sub-Saharan Africa (SSA), increases in yields of the major crops in smallholder farming systems have failed to match population growth, with increased production resulting rather from agricultural area expansion (Worldbank, 2007), very often at the expense of the natural resource base, such as carbon-rich and biodiverse forest land (e.g. Gockowski and Sonwa, 2011). Intensification of smallholder agriculture is a must under high population densities but also desirable in less populated areas in order to protect natural ecosystems. Smallholder farming communities and systems in SSA are heterogeneous, both at the community and farm level, driven by varying and often limited access for production resources (land, labour, capital) (Tittonell et al., 2010). At the community level, variable resource endowments and production objectives are often conceptualized through the construction of farm typologies. At farm level, preferential management of specific plots within a farm has resulted in within-farm soil fertility gradients, often with soils of higher fertility near the homestead, and more degraded soils towards the outer limits of the farm. For many households and regions, agriculture alone will not be able to provide rural populations with adequate livelihoods due to limited farm size and access to land (Harris and Orr, 2014; Jayne et al., 2014). Besides heterogeneity at farm and community level, enabling conditions for intensification, often expressed as access to agro-inputs, markets, and credit, quality of rural infrastructure, or conducive policies, also vary considerably. Intensification of smallholder farming systems will thus require co-learning among research, development, and private sector actors for the tailored integration of both technical and institutional innovations (Giller et al., 2011; Coe et al., 2014).
Innovation platforms: experiences with their institutional embedding in agricultural research for development
Schut, M.L.W. ; Klerkx, L.W.A. ; Sartas, M. ; Lamers, D. ; McCampbell, M. ; Ogbonna, H. ; Kaushik, P. ; Atta-Krah, K. ; Leeuwis, C. - \ 2016
Experimental Agriculture 52 (2016)4. - ISSN 0014-4797 - p. 537 - 561.
Innovation Platforms (IPs) are seen as a promising vehicle to foster a paradigm shift in agricultural research for development (AR4D). By facilitating interaction, negotiation and collective action between farmers, researchers and other stakeholders, IPs can contribute to more integrated, systemic innovation that is essential for achieving agricultural development impacts. However, successful implementation of IPs requires institutional change within AR4D establishments. The objective of this paper is to reflect on the implementation and institutionalisation of IPs in present AR4D programmes. We use experiences from sub-Saharan Africa to demonstrate how the adoption and adaptation of IPs creates both opportunities and challenges that influence platform performance and impact. Niche-regime theory is used to understand challenges, and anticipate on how to deal with them. A key concern is whether IPs in AR4D challenge or reinforce existing technology-oriented agricultural innovation paradigms. For example, stakeholder representation, facilitation and institutional embedding determine to a large extent whether the IP can strengthen systemic capacity to innovate that can lead to real paradigm change, or are merely ‘old wine in new bottles’ and a continuation of ‘business as usual’. Institutional embedding of IPs and – more broadly – the transition from technology-oriented to system-oriented AR4D approaches requires structural changes in organisational mandates, incentives, procedures and funding, as well as investments in exchange of experiences, learning and capacity development.
Capacity to innovate from a system CGIAR research program perspective
Leeuwis, C. ; Schut, M. ; Waters-Bayer, A. ; Mur, R. ; Atta-Krah, K. ; Douthwaite, B. - \ 2014
Penang, Malaysia : CGIAR
System performance analysis of an alley-cropping system in Western Kenya and its explanation by nutrient balances and uptake processes
Radersma, S. ; Otieno, H. ; Atta-Krah, A.N. ; Niang, A.I. - \ 2004
Agriculture, Ecosystems and Environment 104 (2004)3. - ISSN 0167-8809 - p. 631 - 652.
rain-forest zone - gliricidia-sepium - leucaena-leucocephala - agroforestry systems - root distribution - northern kenya - semiarid kenya - water-use - maize - soil
Alley-cropping has successively been overestimated and despised, due to unrealistic expectations of this ¿more natural¿ type of agriculture and the disappointment thereafter, when the negative effects of trees on crops became evident over time. In this paper we examine the performance and underlying mechanisms of a Calliandra (Calliandra calothyrsus Meissn.)¿maize (Zea mays L.) alley-cropping system on a phosphorus (P) limiting Ferralsol in Western Kenya. The system performance analysis methods of [The `dark side¿ of intercropping: manipulation of soil resources. In: Sinoquet, H., Cruz, P. (Eds.), Proceedings of the International Conference on Ecophysiology of Intercropping. INRA, Paris, France, pp. 45¿66] and [Agric. Ecosyst. Environ. 80 (2000) 87] were used as well as mechanistic research into availability, uptake and balances of below ground resources. The Calliandra¿maize system performed worse than sole maize (I=¿66%, according to Ong¿s method) Calliandra affected the less limiting resource nitrogen (N) positively, but the negative effect of Calliandra on P-availability, the main limitation of the environment outweighed the positive or fertility effect, according to Kho¿s performance analysis method. However, after P application, when the main limiting resource for maize in our environment shifted to N, the Calliandra had still only a marginal positive effect on maize yields (insignificant 5% increase of alley-cropping compared to sole maize). This was explained by a negative total N balance in the soil of ¿30 kg ha¿1, and a negative inorganic N balance in the soil of ¿277 kg ha¿1 over the seven seasons. The difference between total and inorganic N balance was due to a mineralisation of only 20% of the N in all the Calliandra mulch applied over the seven seasons. Net negative nutrient balances also explain the general trend of decreasing yields of 40¿90% over the seven seasons. We conclude that the combination of Ong¿s simple method, Kho¿s resource-base explanation and further investigation of long-term supply and availability of the resources that are the main limitation(s) of an environment can give an understanding needed to create productive and sustainable alley-cropping systems.
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