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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    Tropical forage technologies can deliver multiple benefits in Sub-Saharan Africa. A meta-analysis
    Paul, Birthe K. ; Koge, Jessica ; Maass, Brigitte L. ; Notenbaert, An ; Peters, Michael ; Groot, Jeroen C.J. ; Tittonell, Pablo - \ 2020
    Agronomy for Sustainable Development 40 (2020)4. - ISSN 1774-0746
    Crop-livestock systems - Cropping system - Forage agronomy - Forage grass - Herbaceous legume - Livestock productivity - Multi-dimensional impacts - Soil organic carbon - Sustainable intensification

    Scarcity of quantity and quality feed has been a key constraint to productivity of smallholder crop-livestock systems. Tropical forages include a variety of annual and perennial grasses, herbaceous and dual-purpose legumes, and multipurpose trees and shrubs. They have been promoted in Sub-Saharan Africa (SSA) for increasing livestock productivity and household income through higher quantity and quality of herbage, while contributing to soil improvement and higher food crop yields. For the first time, we quantitatively reviewed 72 experimental studies from across SSA to take stock of geographical distribution and forage technology focus of past research; quantify magnitudes of multidimensional impacts of forage technologies; and present variability in forage agronomy data. Improved forage technologies were classified into four groups: (i) germplasm, (ii) management, (iii) cropping system integration, and (iv) feeding regime. Mean weighted response ratios were calculated from 780 pairs of observations for 13 indicators across the five impact dimensions. Improved forage germplasm had on average 2.6 times higher herbage productivity than local controls, with strongest effect in grasses. Feeding regimes with improved leguminous forages increased milk yield by on average 39%, dry matter intake by 25%, and manure production by 24%. When forage technologies were integrated with food crops, soil loss was almost halved, soil organic carbon increased on average by 10%, and grain and stover yields by 60% and 33%, respectively. This study demonstrates the central role improved forages could play in sustainable intensification of crop-livestock systems in SSA. It highlights the need for multidisciplinary and systems-level approaches and studies to quantify synergies and tradeoffs between impact dimensions. Further research is needed to explain forage agronomic yield variability, unraveling interactions between genotype, on-farm environmental conditions, and management factors. Results from this review can inform development programs, prioritizing technologies proven successful for dissemination and indicating magnitudes of expected impacts.

    Effects of proximity to markets on dairy farming intensity and market participation in Kenya and Ethiopia
    Lee, Jan van der; Oosting, Simon ; Klerkx, Laurens ; Opinya, Felix ; Bebe, Bockline Omedo - \ 2020
    Agricultural Systems 184 (2020). - ISSN 0308-521X
    Commercialization - Crop-livestock interaction - Farming system design - Food security - Input supply - Sustainable intensification

    The effect of proximity to markets on dairy farming intensity and market participation traditionally has been viewed as a market quality effect stemming from distance to end-markets with resultant travel time. This study departs from this by distinguishing three travel time components: travel time to local service center for inputs and services, to dairy delivery point, and to end-markets. Dairy farms in nine villages each in Ethiopia and Kenya were sampled and interviewed along a double proximity gradient. Effects on many production and marketing parameters were measured and compared using regression analysis, to test the hypothesis that intensity of dairy farming and degree of market participation increase with proximity to end-markets and with proximity to local service centers. Findings prove the hypothesis for proximity to local service center, which causes better market quality for inputs and outputs, smaller farms with less available labor, use of more purchased feeds and services, higher stocking rates, higher yields, and higher margins per hectare. Findings only partly prove the hypothesis for proximity to end-markets, mainly due to unexpected land scarcity in the most remote locations. Low productivity and low dairy farming intensity and market participation for remote farms in Ethiopia are attributed to limited and volatile market demand, a coarse milk-collection grid, and low quality of input and service markets, which are largely publicly organized. Implication of this study is that the common typology of dairy farms in ‘(peri-) urban’ and ‘rural’ farms needs adjustment by outlining local market access and connectivity. ‘Remote’ rural farms need to be connected to milk collection infrastructure, input shops and services to even have the choice to increase participation in dairy- or other markets.

    Agriculture green development : A model for China and the world
    Shen, Jianbo ; Zhu, Qichao ; Jiao, Xiaoqiang ; Ying, Hao ; Wang, Hongliang ; Wen, Xin ; Xu, Wen ; Li, Tingyu ; Cong, Wenfeng ; Liu, Xuejun ; Hou, Yong ; Cui, Zhenling ; Oenema, Oene ; Davies, William J. ; Zhang, Fusuo - \ 2020
    Frontiers of Agricultural Science and Engineering 7 (2020)1. - ISSN 2095-7505 - p. 5 - 13.
    Agriculture green development - Food security - Interdisciplinary innovations - Resource use efficiency - Sustainable development - Sustainable intensification - Whole industry chain

    Realizing sustainable development has become a global priority. This holds, in particular, for agriculture. Recently, the United Nations launched the Sustainable Development Goals (SDGs), and the Nineteenth National People's Congress has delivered a national strategy for sustainable development in China-realizing green development. The overall objective of Agriculture Green Development (AGD) is to coordinate "green" with "development" to realize the transformation of current agriculture with high resource consumption and high environmental costs into a green agriculture and countryside with high productivity, high resource use efficiency and low environmental impact. This is a formidable task, requiring joint efforts of government, farmers, industry, educators and researchers. The innovative concept for AGD will focus on reconstructing the whole crop-animal production and food production-consumption system, with the emphasis on high thresholds for environmental standards and food quality as well as enhanced human well-being. This paper addresses the significance, challenges, framework, pathways and potential solutions for realizing AGD in China, and highlights the potential changes that will lead to a more sustainable agriculture in the future. Proposals include interdisciplinary innovations, whole food chain improvement and regional solutions. The implementation of AGD in China will provide important implications for the countries in developmental transition, and contribute to global sustainable development.

    Motivational factors influencing farming practices in northern Ghana
    Mellon-Bedi, S. ; Descheemaeker, K. ; Hundie-Kotu, B. ; Frimpong, S. ; Groot, J.C.J. - \ 2020
    NJAS Wageningen Journal of Life Sciences 92 (2020). - ISSN 1573-5214
    Adoption - Factor analysis - Impediments - Motivations - Sustainable intensification

    Socio-economic factors that influence the adoption of management practices and technologies by farmers have received wide attention in the adoption literature, but the effects of socio-psychological farmer features such as perceptions and motivations have been analysed to a lesser extent. Using farm household survey data from three regions in northern Ghana, this study explores farmers’ motivations and perceived adoption impediments for three sustainable intensification practices (SIPs): improved maize varieties, cropping system strategies, and combined SIPs (i.e. improved maize and cropping system strategies), and the effect of motivational factors on decisions to adopt SIPs. First, explorative factor analysis (EFA) was used in identifying factors of motivations and impediments for adoption of SIPs. Then, a multinomial logit model was used to analyze the effect of socio-economic farm characteristics and motivational factors on farmers’ decisions to adopt SIPs. EFA identified three motivational factors: personal satisfaction, eco-diversity and eco-efficiency, which differed in importance between the three regions. Across these regions, higher scores for aspects of personal satisfaction were associated with lower interest in improved maize varieties compared to cropping system strategies, while the opposite was true for eco-efficiency which was related to a stronger preference for improved maize varieties. Uncertainty, absence of social support, and resource constraints were identified as impediment factors. The logit model demonstrated that extension services seemed to support the use of improved maize varieties more than the implementation of cropping system strategies. We conclude that motivational factors significantly influence farmer adoption decisions regarding sustainable intensification practices and should be considered systematically in combination with socio-economic farm features and external drivers to inform on-farm innovation processes and supporting policies.

    Sustainable intensification in Western Kenya : Who will benefit?
    Jindo, Keiji ; Schut, Antonius G.T. ; Langeveld, Johannes W.A. - \ 2020
    Agricultural Systems 182 (2020). - ISSN 0308-521X
    Fertilizer use - Food security - Smallholder farmers - Sustainable intensification

    Sustainable Intensification (SI) is essential for Sub-Saharan Africa (SSA) to meet the food demand of the growing population under conditions of increasing land scarcity. However, access to artificial fertilizers is limited, and the current extension system is not effective in serving smallholder farmers. This paper studies farmers' response to improved fertilizer availability under field conditions. Data on farms and families were collected from 267 smallholder farms, while data on fertilizer use and crop response to fertilizer were collected on 127 farm plots. Fertilizer applications and maize yields were measured, and benefit to cost ratio (BCR) of fertilizer application was calculated and to assess its effect on food security. Farm household typologies were used to determine differences in farm endowment and food security classes. Fertilizer application did not significantly improve maize yields in 2017 due to unfavorable weather conditions and pest infestations, whereas significant yield responses were observed in 2018. Consequently, fertilizer application was economically beneficial (BCR >1) for only 45% of the farmers in 2017, compared to 94% in 2018 when 80% of the farmers passed the technology adaptation point (BCR > 2). Surprisingly, economic returns did not vary significantly between household types, implying that fertilizer application provides comparable benefits across all farm types. This is partly explained by the fact that soil fertility varied little between farm types (soil carbon content, for example, showed no correlation with farmer endowment). Still, large differences were observed in farmers' willingness to invest in larger fertilizer applications. Only a small proportion of farmers is expected to increase fertilizer applications as recommended. Our work demonstrates the need to address risks for smallholders and shows that socio-economic aspects are more important than biophysical constraints for policies promoting sustainable intensification.

    Balancing indicators for sustainable intensification of crop production at field and river basin levels
    Chukalla, Abebe Demissie ; Reidsma, Pytrik ; Vliet, Michelle T.H. van; Silva, João Vasco ; Ittersum, Martin K. van; Jomaa, Seifeddine ; Rode, Michael ; Merbach, Ines ; Oel, Pieter R. van - \ 2020
    Science of the Total Environment 705 (2020). - ISSN 0048-9697
    Crop production - Nitrogen-use efficiency - Selke Basin - Sustainable intensification - Water quality and quantity indicators - Water-use efficiency

    Adequate tools for evaluating sustainable intensification (SI) of crop production for agro-hydrological system are not readily available. Building on existing concepts, we propose a framework for evaluating SI at the field and river basin levels. The framework serves as a means to assess and visualise SI indicator values, including yield, water-use efficiency and nitrogen-use efficiency (NUE), alongside water and nitrogen surpluses and their effects on water quantity and quality. To demonstrate the SI assessment framework, we used empirical data for both the field level (the Static Fertilization Experiment at Bad Lauchstädt) and the river basin level (the Selke basin, 463 km2) in central Germany. Crop yield and resource use efficiency varied considerably from 1980 to 2014, but without clear trends. NUE frequently fell below the desirable range (<50%), exposing the environment to a large N surplus (>80 kg N ha−1). For the catchment as a whole, the average nitrate-N concentration (3.6 mg L−1) was slightly higher than the threshold of 2.5 mg L−1 nitrate-N in surface water. However, weather and climate-related patterns, due to their effects on transport capacity and dilution, influenced water quantity and quality indicators more than agronomic practices. To achieve SI of crop production in the Selke basin, irrigation and soil moisture management are required to reduce yield variability and reduce N surpluses at field level. In addition, optimum application of fertiliser and manure could help to reduce the nitrate-N concentration below the set water quality standards in the Selke basin. In this way, there is scope for increase in yields and resource use efficiencies, and thus potential reduction of environmental impacts at basin level. We conclude that the framework is useful for assessing sustainable production, by simultaneously considering objectives related to crop production, resource-use efficiency and environmental quality, at both field and river basin levels.

    Unravelling the variability and causes of smallholder maize yield gaps in Ethiopia
    Assefa, Banchayehu Tessema ; Chamberlin, Jordan ; Reidsma, Pytrik ; Silva, João Vasco ; Ittersum, Martin K. van - \ 2020
    Food Security 12 (2020)1. - ISSN 1876-4517 - p. 83 - 103.
    Production ecology - Smallholder agriculture - Stochastic frontier analysis - Sustainable intensification - Yield response to N - Zea mays L

    Ethiopia has achieved the second highest maize yield in sub-Saharan Africa. Yet, farmers’ maize yields are still much lower than on-farm and on-station trial yields, and only ca. 20% of the estimated water-limited potential yield. This article provides a comprehensive national level analysis of the drivers of maize yields in Ethiopia, by decomposing yield gaps into efficiency, resource and technology components, and accounting for a broad set of detailed input and crop management choices. Stochastic frontier analysis was combined with concepts of production ecology to estimate and explain technically efficient yields, the efficiency yield gap and the resource yield gap. The technology yield gap was estimated based on water-limited potential yields from the Global Yield Gap Atlas. The relative magnitudes of the efficiency, resource and technology yield gaps differed across farming systems; they ranged from 15% (1.6 t/ha) to 21% (1.9 t/ha), 12% (1.3 t/ha) to 25% (2.3 t/ha) and 54% (4.8 t/ha) to 73% (7.8 t/ha), respectively. Factors that reduce the efficiency yield gap include: income from non-farm sources, value of productive assets, education and plot distance from home. The resource yield gap can be explained by sub-optimal input use, from a yield perspective. The technology yield gap comprised the largest share of the total yield gap, partly due to limited use of fertilizer and improved seeds. We conclude that targeted but integrated policy design and implementation is required to narrow the overall maize yield gap and improve food security.

    Ecological intensification by integrating biogas production into nutrient cycling : Modeling the case of Agroecological Symbiosis
    Koppelmäki, Kari ; Parviainen, Tuure ; Virkkunen, Elina ; Winquist, Erika ; Schulte, Rogier P.O. ; Helenius, Juha - \ 2019
    Agricultural Systems 170 (2019). - ISSN 0308-521X - p. 39 - 48.
    Biological nitrogen fixation - Localized agrifood system - Nutrient losses - Organic farming - Renewable energy - Sustainable intensification

    There is growing demand to produce both food and renewable energy in a sustainable manner, while avoiding competition between food and energy production. In our study, we investigated the potential of harnessing biogas production into nutrient recycling in an integrated system of organic food production and food processing. We used the case of Agroecological Symbiosis (AES) at Palopuro, which is a combination of three farms, a biogas plant, and a bakery, as a case to explore how biogas production using feedstocks from the farms can be used to improve nutrient cycling, and to calculate how much energy could be produced from the within-system feedstocks. The current system (CS) used in organic farms, and the integrated farm and food processing AES system, were analyzed using Substance Flow analysis. In the AES, annual nitrogen (N) and phosphorus (P) surpluses were projected to be reduced from 95 kg ha−1 to 36 kg ha−1 and from 3.4 kg ha−1 to −0.5 kg ha−1 respectively, compared to the CS. Biogas produced from green manure leys as the major feedstock, produced 2809 MWh a−1. This was 70% more than the energy consumed (1650 MWh a−1) in the systemand thus the AES system turned out to be a net energy producer. Results demonstrated the potential of biogas production to enhance the transition to bioenergy, nutrient recycling, and crop productivity in renewable localized farming and food systems.

    Intensification and upgrading dynamics in emerging dairy clusters in the East African highlands
    Lee, Jan van der; Klerkx, Laurens ; Bebe, Bockline Omedo ; Mengistu, Ashenafi ; Oosting, Simon - \ 2018
    Sustainability 10 (2018)11. - ISSN 2071-1050
    Agribusiness cluster - Commercialization - Dairy value chain - Ethiopia - Farming system - Kenya - Service arrangements - Sustainable intensification

    Based on farmer and value chain actor interviews, this comparative study of five emerging dairy clusters elaborates on the upgrading of farming systems, value chains, and context shapes transformations from semi-subsistent to market-oriented dairy farming. The main results show unequal cluster upgrading along two intensification dimensions: dairy feeding system and cash cropping. Intensive dairy is competing with other high-value cash crop options that resource-endowed farmers specialize in, given conducive support service arrangements and context conditions. A large number of drivers and co-dependencies between technical, value chain, and institutional upgrading build up to system jumps. Transformation may take decades when market and context conditions remain sub-optimal. Clusters can be expected to move further along initial intensification pathways, unless actors consciously redirect course. The main theoretical implications for debate about cluster upgrading are that co-dependencies between farming system, market, and context factors determine upgrading outcomes; the implications for the debate about intensification pathways are that they need to consider differences in farmer resource endowments, path dependency, concurrency, and upgrading investments. Sustainability issues for consideration include enabling a larger proportion of resource-poor farmers to participate in markets; enabling private input and service provision models; attention for food safety; and climate smartness.

    Intensification of rice-based farming systems in Central Luzon, Philippines : Constraints at field, farm and regional levels
    Silva, João Vasco ; Reidsma, Pytrik ; Lourdes Velasco, Ma ; Laborte, Alice G. ; Ittersum, Martin K. van - \ 2018
    Agricultural Systems 165 (2018). - ISSN 0308-521X - p. 55 - 70.
    Crop management - Farm structural change - Farmers’ objectives - Integrated assessment - Sustainable intensification - Yield gap

    Understanding the opportunities for sustainable intensification requires an integrated assessment at field, farm and regional levels of past developments. Two hypotheses regarding current rice production in Central Luzon (Philippines) were developed for this purpose. First, we hypothesize that there are trade-offs between rice yields, labour productivity, gross margin and N use efficiency and, second, that farm(er) characteristics and socio-economic conditions at farm and regional level affect the management practices used by farmers. These hypotheses were tested using two household surveys characterizing rice-based farming systems in Central Luzon in terms of changes over time (1966–2012) and spatial variability. Over the past half-century there was an increase in the proportion of irrigated fields and adoption of improved varieties, which allowed the cultivation of a dry season rice crop in Central Luzon. Moreover, transplanting has been replaced by direct-seeding and herbicides substituted hand-weeding. These resulted in greater rice yields and labour productivity, and contributed to gradual transition from subsistence to commercial farming systems, as observed in the increasing proportion of hired labour and rice sold. Our results indicate the existence of a trade-off between rice yields, labour productivity and N use efficiency as yield levels maximising labour productivity and N use efficiency were ca. 25% and 35% lower than climatic potential yield in the wet and dry season, respectively. At field level, this can be explained by 1) the use of transplanting as crop establishment method, which resulted into higher yields but lower labour productivity as compared to direct-seeding, and 2) the high N application levels, which led to higher yields but lower N use efficiency. In contrast, yield levels which maximised gross margin were ca. 80% of the climatic potential in both wet and dry seasons, so there was little trade-off between rice yields and economic performance. Regarding the second hypothesis results were not always conclusive. As an example, N application per ha was negatively associated with farm size and the timing of the first fertiliser application positively associated with household size and with the number of parcels. More intensive practices, and better farm performance, were recorded in the province at the heart of the irrigation system. We thus conclude that closing rice yield gaps in the production systems of Central Luzon incurs trade-offs with environmental and social objectives at field and farm levels but less with economic objectives. However, we could not clearly show whether, and to what extent, management practices used by farmers are influenced by farm or regional level constraints.

    Aquaculture innovation system analysis of transition to sustainable intensification in shrimp farming
    Joffre, Olivier M. ; Klerkx, Laurens ; Khoa, Tran N.D. - \ 2018
    Agronomy for Sustainable Development 38 (2018)3. - ISSN 1774-0746
    Aquaculture innovation systems - Socio-ecological systems - Sustainability transitions - Sustainable intensification

    The shrimp sector has been one of the fastest growing agri-food systems in the last decades, but its growth has entailed negative social and environmental impacts. Sustainable intensification will require innovation in multiple elements of the shrimp production system and its value chain. We use the case of the shrimp sector in the Mekong Delta in Vietnam to explore the constraints in the transition to sustainable intensification in shrimp farming, using an analytical framework based on innovation systems thinking, i.e., an aquaculture innovation systems framework. Using this framework, we conduct a systemic diagnostic of blocking mechanisms, interrelated sets of constraints within the aquaculture sector that hinder a transition toward sustainable intensification. Our findings show that the major constraints are institutional, with limited enforcement of the regulatory framework for input quality control, disease control, and wastewater management, and a lack of coordination between government bodies to design and enforce this framework. At farm level, limited access to capital favors pond mismanagement and the use of low-quality inputs. The absence of multi-stakeholder initiatives to foster dialog between actors in the value chain constrains the response to new regulations dictated by international market demand. Because of shrimp farming’s connectivity with the wider ecosystem, sustainable intensification in shrimp farming will require collective management of water resources at the landscape level for disease and water pollution control. Ecological principles for pond management need to be promoted to farmers in order to reduce farmers’ inefficient practices and build their capacity to understand new techniques and inputs available in the Vietnamese market. Our paper demonstrates for the utility of a multi-level, multi-dimension, and multi-stakeholder aquaculture innovation systems approach to analyze and address these blocking mechanisms in the transition to sustainable intensification in shrimp farming and aquaculture more broadly.

    Assessing the Greenhouse Gas Mitigation effect of removing bovine trypanosomiasis in Eastern Africa
    MacLeod, Michael ; Eory, Vera ; Wint, William ; Shaw, Alexandra ; Gerber, Pierre J. ; Cecchi, Giuliano ; Mattioli, Raffaele ; Sykes, Alasdair ; Robinson, Timothy - \ 2018
    Sustainability 10 (2018)5. - ISSN 2071-1050
    Cattle health - Climate change - GLEAM - Livestock modelling - Sustainable intensification

    Increasing the production of meat and milk within sub-Saharan Africa should provide significant food security benefits. However, greenhouse gas (GHG) emissions represent a challenge, as cattle production in the region typically has high emissions intensity (EI), i.e., high rates of GHG emissions per unit of output. The high EI is caused by the relatively low production efficiencies in the region, which are in turn partly due to endemic cattle diseases. In theory, improved disease control should increase the efficiency and decrease the emissions intensity of livestock production; however quantitative analysis of the potential GHG mitigation effects of improved disease control in Africa is lacking. This paper seeks to respond to this by using a hybrid modelling approach to quantify the production and emissions effects of removing trypanosomiasis from East African cattle production systems. The emissions are quantified for each cattle production system using an excel version of GLEAM, the Food and Agriculture Organization's Global Livestock Environmental Assessment Model. The results indicate that removing trypanosomiasis leads to a reduction in the emissions intensity per unit of protein produced of between 0% and 8%, driven mainly by the increases in milk yields and cow fertility rates. Despite the limitations, it is argued that the approach provides considerable scope for modelling the GHG impacts of disease interventions.

    Yield gap analysis and entry points for improving productivity on large oil palm plantations and smallholder farms in Ghana
    Rhebergen, Tiemen ; Fairhurst, Thomas ; Whitbread, Anthony ; Giller, Ken E. ; Zingore, Shamie - \ 2018
    Agricultural Systems 165 (2018). - ISSN 0308-521X - p. 14 - 25.
    Boundary line analysis - Crop recovery - Oil extraction rates - Sustainable intensification - Yield gap analysis

    Oil palm production must increase in Ghana to meet the increasing demand for palm oil and avoid costly imports. Although maximum fruit bunch (FB) yields of >20 t ha−1 yr−1 are achievable, average FB yields in Ghana are only 7 t ha−1 yr−1. Despite the pressing need to increase palm oil production and improve yields, knowledge of the underlying causes of poor yields in Ghana is lacking. Closing yield gaps in existing plantings in smallholdings and plantations offers great opportunities to increase oil production without area expansion, thus sparing land for other uses. This study sought to understand the magnitude and underlying causes of yield gaps in plantation and smallholder oil palm production systems in Ghana based on a detailed characterization of management practices and yield measurements over a two-year period. Using a boundary line analysis, the water-limited yield (Yw) over a planting cycle was defined as about 21 t ha−1 yr−1 FB, with yield gaps of 15.4 t ha−1 yr−1 FB at smallholder farms and 9.8 t ha−1 yr−1 FB at plantations. Poor management practices, including incomplete crop recovery (i.e., harvesting all suitable crop) and inadequate agronomic management were the main factors contributing to these yield gaps. Productivity losses were further exacerbated by low oil extraction rates by small-scale processors of 12% as compared to 21% by the large-scale processors. The potential losses in annual crude palm oil (CPO) during the crop plateau yield phase therefore exceed 5 and 3 t ha−1 yr−1 for small-scale and large-scale production systems respectively. Investment to reduce yield gaps by appropriate agronomic and yield recovery practices across all production systems, while improving access of smallholder producers to more efficient oil palm processing facilities, can make a significant contribution to closing the supply gap for palm oil in Ghana. The impact of such investments on large-scale plantations could result in a doubling of CPO production. Smallholder farmers could benefit the most with a fourteen-fold increase in CPO production and economic gains of >1 billion US$.

    Crop vs. tree : Can agronomic management reduce trade-offs in tree-crop interactions?
    Sida, Tesfaye Shiferaw ; Baudron, Frédéric ; Hadgu, Kiros ; Derero, Abayneh ; Giller, Ken E. - \ 2018
    Agriculture, Ecosystems and Environment 260 (2018). - ISSN 0167-8809 - p. 36 - 46.
    Agroforestry - Income diversification - Multifunctional landscape - Sustainable intensification - Trade-off analysis - Yield penalty
    Scattered trees dominate smallholder agricultural landscapes in Ethiopia, as in large parts of sub-Saharan Africa (SSA). While the inclusion of scattered trees could provide a viable pathway for sustainable intensification of these farming systems, they also lead to trade-offs. We carried out a study to: 1) explore the rationale of farmers to maintain on-farm trees beyond crop yield; 2) quantify the impact of agronomic practices on the outcome of tree-crop interactions; and 3) analyse partial economic trade-offs for selected on-farm tree species at farm scale. We recorded agronomic practices within the fields of 135 randomly selected farms from seedbed preparation to harvesting. A multivariate analysis showed that farmers maintained on-farm trees because of their direct timber, fencing, fuelwood, and charcoal production values. Trees generally had a significant negative effect on maize yield. Mean grain yields of 1683, 1994 and 1752 kg ha−1 under the canopies of Cordia, Croton and Acacia, respectively, were significantly lower than in their paired open field with mean yields of 4063, 3415 and 2418 kg ha−1. Besides, more income from trees was accompanied by less income from maize, highlighting trade-offs. However, agronomic practices such as early planting, variety used, improved weed management, fine seedbed preparation and higher rates of nitrogen fertilizer significantly reduced yield penalties associated with trees. We found an inverse relationship between land size and on-farm tree density, implying that the importance of trees increases for land-constrained farms. Given the expected decline in per capita land size, scattered trees will likely remain an integral part of these systems. Thus, utilizing ‘good agronomic practices’ will be vital to minimize tree-crop trade-offs in the future.
    Crop yield gap and stability in organic and conventional farming systems
    Schrama, M. ; Haan, J.J. de; Kroonen, M. ; Verstegen, H. ; Putten, W.H. Van der - \ 2018
    Agriculture, Ecosystems and Environment 256 (2018). - ISSN 0167-8809 - p. 123 - 130.
    Ecological intensification - Nutrient leaching - Soil communities - Spatial stability - Sustainable intensification - Variability
    A key challenge for sustainable intensification of agriculture is to produce increasing amounts of food and feed with minimal biodiversity loss, nutrient leaching, and greenhouse gas emissions. Organic farming is considered more sustainable, however, less productive than conventional farming. We analysed results from an experiment started under identical soil conditions comparing one organic and two conventional farming systems. Initially, yields in the organic farming system were lower, but approached those of both conventional systems after 10–13 years, while requiring lower nitrogen inputs. Unexpectedly, organic farming resulted in lower coefficient of variation, indicating enhanced spatial stability, of pH, nutrient mineralization, nutrient availability, and abundance of soil biota. Organic farming also resulted in improved soil structure with higher organic matter concentrations and higher soil aggregation, a profound reduction in groundwater nitrate concentrations, and fewer plant-parasitic nematodes. Temporal stability between the three farming systems was similar, but when excluding years of Phytophthora outbreaks in potato, temporal stability was higher in the organic farming system. There are two non-mutually exclusive mechanistic explanations for these results. First, the enhanced spatial stability in the organic farming system could result from changes in resource-based (i.e. bottom-up) processes, which coincides with the observed higher nutrient provisioning throughout the season in soils with more organic matter. Second, enhanced resource inputs may also affect stability via increased predator-based (i.e. top-down) control. According to this explanation, predators stabilize population dynamics of soil organisms, which is supported by the observed higher soil food web biomass in the organic farming system.We conclude that closure of the yield gap between organic and conventional farming can be a matter of time and that organic farming may result in greater spatial stability of soil biotic and abiotic properties and soil processes. This is likely due to the time required to fundamentally alter soil properties.
    Soyabean response to rhizobium inoculation across sub-Saharan Africa : Patterns of variation and the role of promiscuity
    Heerwaarden, Joost van; Baijukya, Frederick ; Kyei-Boahen, Stephen ; Adjei-nsiah, Samuel ; Ebanyat, Peter ; Kamai, Nkeki ; Wolde-Meskel, Endalkachew ; Kanampiu, Fred ; Vanlauwe, Bernard ; Giller, Ken - \ 2018
    Agriculture, Ecosystems and Environment 261 (2018). - ISSN 0167-8809 - p. 211 - 218.
    Bradyrhizobium - Promiscuous varieties - Response variability - Smallholder farmers - Soyabean - Sub saharan Africa - Sustainable intensification
    Improving bacterial nitrogen fixation in grain legumes is central to sustainable intensification of agriculture in sub-Saharan Africa. In the case of soyabean, two main approaches have been pursued: first, promiscuous varieties were developed to form effective symbiosis with locally abundant nitrogen fixing bacteria. Second, inoculation with elite bacterial strains is being promoted. Analyses of the success of these approaches in tropical smallholder systems are scarce. It is unclear how current promiscuous and non-promiscuous soyabean varieties perform in inoculated and uninoculated fields, and the extent of variation in inoculation response across regions and environmental conditions remains to be determined.We present an analysis of on-farm yields and inoculation responses across ten countries in Sub Saharan Africa, including both promiscuous and non-promiscuous varieties. By combining data from a core set of replicated on-farm trials with that from a large number of farmer-managed try-outs, we study the potential for inoculation to increase yields in both variety types and evaluate the magnitude and variability of response.Average yields were estimated to be 1343 and 1227. kg/ha with and without inoculation respectively. Inoculation response varied widely between trials and locations, with no clear spatial patterns at larger scales and without evidence that this variation could be explained by yield constraints or environmental conditions. On average, specific varieties had similar uninoculated yields, while responding more strongly to inoculation. Side-by side comparisons revealed that stronger responses were observed at sites where promiscuous varieties had superior uninoculated yields, suggesting the availability of compatible, effective bacteria as a yield limiting factor and as a determinant of the magnitude of inoculation response.
    Agricultural intensification scenarios, household food availability and greenhouse gas emissions in Rwanda : Ex-ante impacts and trade-offs
    Paul, B.K. ; Frelat, R. ; Birnholz, C. ; Ebong, C. ; Gahigi, A. ; Groot, J.C.J. ; Herrero, M. ; Kagabo, D.M. ; Notenbaert, A. ; Vanlauwe, B. ; Wijk, M.T. van - \ 2018
    Agricultural Systems 163 (2018). - ISSN 0308-521X - p. 16 - 26.
    Climate smart agriculture - Ex-ante impact assessment - Household modeling - Low carbon development - Sub-Saharan Africa - Sustainable intensification
    Rwanda's agricultural sector is facing severe challenges of increasing environmental degradation, resulting in declining productivity. The problem is likely to be further aggravated by the growing population pressure. A viable pathway is climate smart agriculture, aiming at the triple win of improving food security and climate change adaptation, while contributing to mitigation if possible. The Government of Rwanda has initiated ambitious policies and programs aiming at low emission agricultural development. Crop focused policies include the Crop Intensification Program (CIP) which facilitates access to inorganic fertilizer and improved seeds. In the livestock subsector, zero-grazing and improved livestock feeding are encouraged, and the Girinka program provides poor farm households with a crossbred dairy cow. In this study, we aimed at assessing the potential impact of these policy programs on food availability and greenhouse gas (GHG) emissions of 884 households across different agro-ecologies and farming systems in Rwanda. Household level calculations were used to assess the contribution of current crops, livestock and off-farm activities to food availability and GHG emissions. Across all sites, 46% of households were below the 2500kcalMAE-1 yr-1 line, with lower food availability in the Southern and Eastern Rwanda. Consumed and sold food crops were the mainstay of food availability, contributing between 81.2% (low FA class) to 53.1% (high FA class). Livestock and off-farm income were the most important pathways to higher FA. Baseline GHG emissions were low, ranging between 395 and 1506kg CO2e hh-1 yr-1 per site, and livestock related emissions from enteric fermentation (47.6-48.9%) and manure (26.7-31.8%) were the largest contributors to total GHG emissions across sites and FA classes. GHG emissions increased with FA, with 50% of the total GHG being emitted by 22% of the households with the highest FA scores. Scenario assessment of the three policy options showed strong differences in potential impacts: Girinka only reached one third of the household population, but acted highly pro-poor by decreasing the households below the 2500kcalMAE-1 yr-1 line from 46% to 35%. However, Girinka also increased GHG by 1174kg CO2e hh-1 yr-1, and can therefore not be considered climate-smart. Improved livestock feeding was the least equitable strategy, decreasing food insufficient households by only 3%. However, it increased median FA by 755kcalMAE-1 yr-1 at a small GHG increase (50kg CO2e hh-1 yr-1). Therefore, it is a promising option to reach the CSA triple win. Crop and soil improvement resulted in the smallest increase in median FA (FA by 755kcalMAE-1 yr-1), and decreasing the proportion of households below 2500kcalMAE-1 yr-1 by 6%. This came only at minimal increase in GHG emissions (23kg CO2e hh-1 yr-1). All policy programs had different potential impacts and trade-offs on different sections of the farm household population. Quick calculations like the ones presented in this study can assist in policy dialogue and stakeholder engagement to better select and prioritize policies and development programs, despite the complexity of its impacts and trade-offs.
    A Functional Land Management conceptual framework under soil drainage and land use scenarios
    Coyle, Cait ; Creamer, Rachel E. ; Schulte, Rogier P.O. ; O'Sullivan, Lilian ; Jordan, Phil - \ 2016
    Environmental Science & Policy 56 (2016). - ISSN 1462-9011 - p. 39 - 48.
    Agriculture - Ecosystem service - Soil functions - Sustainable intensification

    Agricultural soils offer multiple soil functions, which contribute to a range of ecosystem services, and the demand for the primary production function is expected to increase with a growing world population. Other key functions on agricultural land have been identified as water purification, carbon sequestration, habitat biodiversity and nutrient cycling, which all need to be considered for sustainable intensification. All soils perform all functions simultaneously, but the variation in the capacity of soils to supply these functions is reviewed in terms of defined land use types (arable, bio-energy, broadleaf forest, coniferous forest, managed grassland, other grassland and Natura 2000) and extended to include the influence of soil drainage characteristics (well, moderately/imperfect, poor and peat). This latter consideration is particularly important in the European Atlantic pedo-climatic zone; the spatial scale of this review. This review develops a conceptual framework on the multi-functional capacity of soils, termed Functional Land Management, to facilitate the effective design and assessment of agri-environmental policies. A final functional soil matrix is presented as an approach to show the consequential changes to the capacity of the five soil functions associated with land use change on soils with contrasting drainage characteristics. Where policy prioritises the enhancement of particular functions, the matrix indicates the potential trade-offs for individual functions or the overall impact on the multi-functional capacity of soil. The conceptual framework is also applied by land use area in a case study, using the Republic of Ireland as an example, to show how the principle of multi-functional land use planning can be readily implemented.

    Report of the kick off meeting of the Knowledge Network on Sustainable Intensification (KNSI), 3 June 2016, Wageningen
    Bura, M. ; Boekhorst, D. te - \ 2016
    FACCE-JPI
    FACCE - FACCE JPI - KNSI - Sustainable intensification - knowlegde network - agriculture - food security - climate change - FACCE JPI - knowledge network - sustainable intensification - FACCE-JPI - Bioeconomy
    Determinants of crop-livestock integration in Brazil : Evidence from the household and regional levels
    Dias Bernardes Gil, Juliana ; Garrett, R. ; Berger, T. - \ 2016
    Land Use Policy 59 (2016). - ISSN 0264-8377 - p. 557 - 568.
    Agricultural technology diffusion - Integrated systems - Land cover change - Pasture degradation - Sustainable intensification

    Integrated crop-livestock systems (iCL) are advocated as a promising strategy to increase agricultural production and rehabilitate degraded pastures while mitigating GHG emissions. Although iCL in Brazil has increased over the past few years, it still occupies a small share of the country's total agricultural area. We investigate the determinants of iCL occurrence in Mato Grosso state, a globally important producer of beef cattle and grains that has experienced rapid land cover change and environmental degradation in recent decades. Our analysis encompasses two typical cases of iCL in Mato Grosso (the rotation of soy followed by pasture, and soy followed by maize and pasture) as well as biophysical, socioeconomic, and institutional factors observable at the household and/or municipality levels that may influence the wide-scale occurrence of iCL. Evidence at both scales suggests that knowledge and supply chain infrastructure play an important role in early occurrence of iCL, as they are more common in regions closer to iCL research stations and processing facilities of grains and cattle. On average iCL adopters are more educated and have better access to technical assistance and sector information than specialized farmers or ranchers. Most iCLs are concentrated near established soy areas and greater similarity exists between municipalities with iCL and soy-dominant municipalities vs. pasture-dominant municipalities. Our findings reveal the importance of specific conditions for iCL occurrence and iCL promotion in livestock-dominant regions. Incentives targeted at ranchers are crucial for the achievement of the Brazilian Government's goal to restore degraded pastures through agricultural intensification.

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