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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    Fertiliser application practices and nutrient deficiencies in smallholder oil palm plantations in Indonesia
    Woittiez, L.S. ; Turhina, Sri ; Deccy, D. ; Slingerland, Maja ; Noordwijk, Meine van; Giller, Ken E. - \ 2019
    Experimental Agriculture 55 (2019)4. - ISSN 0014-4797 - p. 543 - 559.
    Oil palm has become an important source of revenue for smallholders in Indonesia, but productivity of smallholder plantations is generally poor. Nutrient limitations have been suggested as an important agronomic constraint to yield. Our research aimed to quantify fertiliser use, soil and tissue nutrient status, and palm growth and yield in a sample of independent smallholder plantations. We selected 49 plantations in Indonesia in two provinces with contrasting soils. For all plantations, we obtained self-reported fertiliser use and yield data, collected soil and tissue samples, and analysed vegetative growth. More than 170 kg N ha−1 year−1 was applied in one site, and P was applied in excess of recommended quantities in both sites, but on average farmers applied less than 100 kg K ha−1 year−1. Soils in the palm circle were poor in N, P and K in 29, 40 and 82% of the plantations, and deficiencies were measured in 57, 61 and 80% of the leaflet samples, respectively. We found statistically significant correlations between tissue nutrient concentrations and vegetative growth, but a large part of the variation in the data remained unaccounted for. Single leaf area was reduced in >80% of the plantations. Average yields were estimated to be 50‒70% of the water-limited potential. Our results demonstrate that widespread nutrient imbalances and deficiencies, especially potassium and phosphorus, occur in smallholder oil palm plantations, due to inadequate and unbalanced fertiliser application practices. These deficiencies may be an important underlying cause of the overall poor productivity, which threatens the economic and environmental sustainability of the smallholder sector.
    Agricultural land use change and associated driving forces over the past 180 years in two municipalities of the Brazilian Cerrado
    Arruda, Murilo Rodrigues de; Slingerland, Maja ; Santos, José Zilton Lopes ; Giller, Ken E. - \ 2019
    GeoJournal 84 (2019)3. - ISSN 0343-2521 - p. 555 - 570.
    Agriculture - Case study - Cattle - Cerrado - Crops - Sugarcane
    This paper aims to test the hypothesis that a single driving force from the local, national, or global level is capable of triggering land use changes, including large scale deforestation, within a historical context. To reach this goal we describe and explain the driving forces from the global to farm level that have shaped agricultural land uses, as a case study, over 180 years in the municipalities of Quirinópolis and Gouvelândia in the Brazilian Cerrado. Through secondary data, field surveys, and interviews with farmers and other stakeholders involved with agricultural production, we identified four distinct periods in which drastic or little land use occurred. The evidence found supports our hypothesis. Two drastic land use changes occurred in Quirinópolis and Gouvelândia. The first one was the replacement of about 400,000 ha of original vegetation by pastures and crops between 1965 and 1985 triggered by the availability of abundant subsidized rural credits for farmers; the second one was initiated in 2005 with the replacement of 100,000 ha of pastures and cropping area by sugarcane, which was driven by the sudden domestic and world demand for sugar and ethanol.
    Is RSPO certification having an impact on smallholders decisions to expand or intensify production? : Science-for-policy brief for RSPO by the Sensor Programme
    Slingerland, M.A. - \ 2018
    Wageningen University & Research - 3 p.
    Aquaponics, an inclusive business to save land and water and to provide nutritious diets to vulnerable groups
    Slingerland, M.A. ; Kappers, B. ; Abebe, T. ; Getahun, A. - \ 2018
    Aquaponics, an inclusive business to save land and water and to provide nutritious diets to vulnerable groups
    Slingerland, Maja - \ 2018
    From oil palm monoculture to integration with crops and livestock to enhance resilience of oil palm farming systems
    Slingerland, Maja - \ 2018
    From oil palm monoculture to integration with crops and livestock to enhance resilience of oil palm farming systems
    Slingerland, M.A. ; Migeon, A. ; Khasanah, N. ; Meer, P.J. van der; Koekkoek, Solveigh - \ 2018
    Developing an atlas of yield potential and yield gaps for current oil palm plantation area in Indonesia
    Grassini, Patricio ; Rattalino Edreira, Juan I. ; Andrade, Jose ; Ven, G.W.J. van de; Hekman, Willem ; Beuken, Rob van den; Ittersum, M.K. van; Rahutomo, Suroso ; Sutarta, Edy Sigit ; Agus, F. ; Oberthür, Thomas ; Slingerland, M.A. - \ 2018
    Estimating yield gaps in oilpalm in Indonesia using PALMSIM to inform policy on the scope of intensification
    Hekman, Willem ; Slingerland, M.A. ; Beuken, Rob van den; Ven, G.W.J. van de; Grassini, Patricio ; Andrade, Jose ; Rattalino Edreira, Juan I. ; Rahutomo, Suroso ; Sutarta, Edy Sigit ; Agus, F. - \ 2018
    Partnerships in research for sustainable palm oil
    Slingerland, M.A. - \ 2018
    The Missing Middle in SDG 2: The dual disconnect between global goals and local contexts, and between food production and consumption
    Veldhuizen, L.J.L. ; Giller, K.E. ; Boer, I.J.M. de; Oosterveer, P.J.M. ; Brouwer, I.D. ; Janssen, S.J.C. ; Zanten, H.H.E. van; Slingerland, M.A. - \ 2018
    Session S6
    Brechas de rendimeinto en el cultivo de palma de aceite: una revision cuantitativa de factores determinantes
    Woittiez, L.S. ; Wijk, Mark T. van; Slingerland, M.A. ; Noordwijk, M. van; Giller, K.E. - \ 2018
    Revista Palmas 39 (2018)1. - p. 16 - 68.
    Costs and benefits of certification of independent oil palm smallholders in Indonesia
    Hutabarat, S. ; Slingerland, Maja ; Rietberg, P.I. ; Dries, L.K.E. - \ 2018
    International Food and Agribusiness Management Review 21 (2018)6. - ISSN 1096-7508 - p. 681 - 700.
    RSPO - certification - smallholders - Indonesia - oil palm - costs and benefits
    Sustainable certification schemes have surged in years. The introduction of these schemes poses serious challenges to smallholders. One such certification scheme is the Roundtable on Sustainable Palm Oil (RSPO), which uses certification to increase equitable and sustainable production of palm oil. This study calculates upfront and recurrent costs and monetary benefits of RSPO certification of the Amanah Independent Oil Palm Smallholders Association in Ukui District, Indonesia. Survey and interview data was collected between 2013 and 2015. Results show that upfront costs of certification were 86 euro per hectare. Furthermore, despite generating up to 21% higher revenues from sales, certification created up to an 8%loss of net income per hectare on average per smallholder in the first year after certification, compared to the situation prior to certification. To motivate smallholders for RSPO certification, the economic performance of certified oil palm smallholders should be improved. This can result from further yield increases, a guaranteed premium price or the sales of GreenPalm certificates to provide additional income.
    Nutritional imbalance in smallholder oil palm plantations in Indonesia
    Woittiez, Lotte S. ; Slingerland, Maja ; Rafik, Rukaiyah ; Giller, Ken E. - \ 2018
    Nutrient Cycling in Agroecosystems 111 (2018)1. - ISSN 1385-1314 - p. 73 - 86.
    Fertiliser - Good agricultural practices - Nutrient management - Soil fertility - Training - Yield
    In Indonesia more than 40% of the area under oil palm is owned by smallholders. The productivity in smallholder plantations is usually less than in large plantations, and limited fertiliser applications may be one of the key reasons. We investigated the use of fertilisers by > 300 smallholder farmers in Sumatra and Kalimantan, some of whom were involved in training programmes aimed at yield improvement. In our sample, the total applications of N were largest (166 kg ha−1 year−1), followed by K (122 kg) and P (56 kg). The applications of K were insufficient to compensate for the off-take with a production of 20 tonne fruit bunches ha−1 year−1, while N applications were excessive. On average, farmers applied 1130 kg fertiliser ha−1 year−1, and relied strongly on subsidised fertilisers, especially NPK Ponska (66%) and urea (39%). The average costs for fertiliser application were USD 225 ha−1 year−1. Trained farmers applied significantly more P in one research area, but for the other nutrients and research areas, there was no significant difference between trained and untrained farmers. Plantation size and nutrient application were weakly correlated in some areas, but not in the sample as a whole. Previously reported nutrient application rates were mostly less than our findings indicated, suggesting that actual nutrient limitations may be more severe. To overcome nutrient limitations and enhance nutrient use efficiency, we recommend that fertilisers are used in the correct balance; a ground cover vegetation is maintained to protect against erosion; and the application of empty fruit bunches is encouraged.
    Can good Agricultural practices sustain oil palm yields for bioenergy production in northeast Thailand?
    Somnuek, Siriluk ; Slingerland, Maja - \ 2018
    Experimental Agriculture 54 (2018)6. - ISSN 0014-4797 - p. 915 - 930.

    The government of Thailand aims for sustainability of palm oil production in the Northeast for bioenergy and farmers’ income. This study investigated whether producers in Northeast Thailand managed their oil palm according to good agricultural practices (GAP) and if not, what effects this has on yield. A survey was conducted amongst 108 randomly selected farmers. For 25 selected plots, management and yields were monitored twice a month for two full years. Compliance to GAP was high for weeding, harvesting, pruning and pest and disease control but not for irrigation (40%) and fertiliser application (20–40%). GAP adoption scores per households positively correlated with income from other crops, tree age and degree of training. We showed that rainfall was insufficient for good oil palm growth between October and April. In the monitored group, use of irrigation and amounts of N, P, K and Mg applied were strongly correlated. The yield was significantly greater with irrigation and fertiliser, reaching similar levels as in the South of Thailand (up to 25–30 Mg Fresh Fruit Bunches: FFB ha−1), but did not differ with soil texture. This allows us to conclude that better application of GAP, especially including a combination of irrigation and fertilisers overcame the unsuitable soil and rainfall conditions in the Northeast of Thailand. However, the costs of fertilisers compared to the price of FFB affected the profitability of FFB production, which may affect farmers’ motivation to apply GAP, especially on unsuitable soils. When the government aims for sustainable palm oil production in the Northeast it needs to invest in frequent technical support, irrigation infrastructure and affordable fertilisers. Otherwise, farmers may not apply GAP because of low returns on investments and yields will remain very modest.

    Palm oil expansion in tropical forest margins or sustainability of production? : Focal issues of regulations and private standards
    Noordwijk, M. van; Pacheco, Pablo ; Slingerland, M.A. ; Dewi, S. ; Khasanah, N. - \ 2017
    Bogor : World Agroforestry Centre (Working Paper 274) - 72
    Indonesia, Malaysia, Elaeis guineensis, certification, RSPO, ISPO
    Palm oil expansion captures headlines, primarily out of concern that encroachment to tropical forest causes environmental problem and ignites social issues. Cascading ecological and social issues cause loss of trust, (threats of) consumer boycotts and multiple standards and certification responses. However, diverse sustainability issues should be taken into account within the issue-attention cycle. Most of current production (89%) occurs in SE Asia, with Indonesia in the lead. Peru and Cameroon are examples of current expansion elsewhere. In Indonesia two phases of new establishment of palm oil coexist within a forest transition gradient: (i) (industry-led) expansion into new forest margins with many social and ecological consequences; and (ii) (often farmer-led) conversion of existing agroforestry and tree crop (often rubber-based) or pasture economies in mosaic landscapes. External consumer concerns refer to the expansion phase, rather than to production sustainability or issues of smallholder concern. However, certification standards are only partially adjusted to the latter. After a ‘voluntary industry standards’ phase of differentiation with and shifting blame to non-certified others, government involvement in Malaysia and Indonesia suggests that standards and certification can trickle down to enforceable good practice standards for all. This leads to ineffective policies that does not address the real issues in local context. On the other hand, subnational jurisdictional entities are the scale at which oil palm production can be balanced with other goals, such as forest conservation and smallholder welfare.
    Open Science Meeting 2017 Towards resilient society
    Slingerland, Maja - \ 2017
    Food, water and energy: smart and local solutions (2) : From trade-offs to synergies
    Stakeholder workshop oil palm cooperation Netherlands-Malaysia
    Slingerland, Maja - \ 2017
    Malaysia – Netherlands Oil Palm Collaboration with MPOB 2017 – 2020
    The Missing Middle in Sustainable Development Goal 2
    Veldhuizen, L.J.L. ; Boer, I.J.M. de; Brouwer, I.D. ; Giller, K.E. ; Janssen, S.J.C. ; Oosterveer, P.J.M. ; Slingerland, M.A. ; Zanten, H.H.E. van - \ 2017
    Foreign investment, organizational innovation and transformation in food supply chains : evidence from the Ethiopian barley sector
    Tefera, Delelegne Abera - \ 2017
    Wageningen University. Promotor(en): S.W.F. Omta, co-promotor(en): W.J.J. Bijman; M.A. Slingerland. - Wageningen : Wageningen University - ISBN 9789463437165 - 217
    foreign investment - organizations - innovations - management science - food supply - supply chain management - farmers - barley - economic sectors - ethiopia - east africa - buitenlandse investering - organisaties - innovaties - bedrijfswetenschap - voedselvoorziening - ketenmanagement - boeren - gerst - economische sectoren - ethiopië - oost-afrika

    Driven by rapid urbanization, economic growth, and changes in consumption patterns, food chains in emerging and developing economies are experiencing a fundamental transformation process. This transformation is usually characterized by increased vertical coordination, growth of modern distribution channels (e.g. supermarkets), consolidation of retail markets, and an increase in export orientation. The rapid growth in demand of modern food with higher quality and safety attracts multinational enterprises to invest in agriculture and food processing in emerging economies. The appearance of multinationals in the food systems of developing countries has been claimed to have a positive impact on economic development and reduction of poverty. The multinationals have adopted modern supply chain management practices for securing a large volume and consistent supply of high quality products. They introduce new technologies that boost productivity and post-harvest management for product upgrading.

    While so far most research on the modernization of food systems has focused on export chains, there is growing interest in the transformation of domestic and staple food chains. Upgrading domestic food chains is needed for a more efficient supply to fast growing urban markets and to sustain access to affordable food for the rapidly growing urban consumers in sub-Saharan Africa. As domestic food value chains are more inclusive than high-value export chains, upgrading these food chains can contribute more to poverty reduction and food security. However, much remains to be understood about the process of modernization in domestic food chains and its implications for rural development. The overarching aim of this dissertation was to deepen our understanding on how organizational innovations facilitate modernization of domestic food chains using case studies from the Ethiopian barley sector. In particular, the thesis examines the effectiveness and impacts of foreign direct investments (FDI), contract farming arrangements (CFAs), producer organizations (POs), and partnerships on the upgrading of malt barley value chains and welfare of local suppliers. To address this objective, we use a combination of qualitative and quantitative research approaches. Data were analyzed using parametric and non-parametric econometric models.

    The findings from the empirical chapters show that: First, our analysis reveals that the appearance of foreign companies in the malt barley chain has brought important changes in the structure and economics of the barley value chain, resulting in the development of a modern chain next to the conventional chain. It is also shown that participation in modern supply chains is determined by a range of factors that include farmer and farm characteristics. Second, the results show that participation in modern supply chains has a positive and significant impact on commercialization, intensification, quality improvement and farm gate prices, ultimately resulting in increased farmer income and spillovers towards productivity of other food crops. Third, we found that POs perform diverse economic functions to enhance rural development , but tighter coordination in food value chains demands alignment of chain activities among actors which leads to changes in the strategies and functions of POs. Fourth, we showed that POs have a positive impact on farm productivity and smallholder income. However, this positive impact of POs come at the expense of inclusiveness, i.e. POs are less inclusive. Thus, there is a tension between business performance and inclusiveness of POs. Moreover, the results show that the motivation to participate in a PO is determined by demographic and economic factors. Lastly, we found that the determinants of quality improvement at farm level are socioeconomic, technological and institutional factors. Specifically, the identified factors are farmers’ level of education, age (as a proxy for farming experience), entrepreneurial attitude, PO membership, CFA participation, and type of improved seed varieties. The thesis concludes that enhancing the modernization of food value chains involving smallholders requires organizational innovation that facilitate coordination and collaborative activities among chain actors.

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