Multi-Functional Land Use Is Not Self-Evident for European Farmers: A Critical Review
Schröder, Jaap J. ; Berge, Hein F.M. Ten; Bampa, Francesca ; Creamer, Rachel E. ; Giraldez-Cervera, Juan V. ; Henriksen, Christian B. ; Olesen, Jørgen E. ; Rutgers, Michiel ; Sandén, Taru ; Spiegel, Heide - \ 2020
Frontiers in Environmental Science 8 (2020). - ISSN 2296-665X
ecosystem services - land management - primary productivity - soil degradation - soil function - soil health - soil quality
Soils perform more functions than primary productivity. Examples of these functions are the recycling of nutrients, the regulation and purification of water, the regulation of the climate, and supporting biodiversity. These abilities are generally referred to as the soil quality. Soil management that favors primary productivity may have positive and negative impacts on the other functions, and vice versa, depending on soil and climatic conditions. All these functions are under pressure, particularly in intensive agriculture. In the absence of mandatory regulations, most European farmers give limited attention to other functions than primary productivity in spite of recommendations by scientists, society and policy makers to acknowledge the ecosystem services provided by soils. The present paper analyses the underlying causes of this limited attention for the multi-functionality of soils by farmers. It is concluded that their focus on primary productivity may stem from (1) insufficient visible proof for soil degradation and benefits of preventive measures over curative measures, (2) limited awareness or conviction of long-term synergies, (3) insufficient remuneration of ecosystem services by society or compensation of yield penalties in favor of these services, (4) lacking trustworthy knowledge about and support for multi-functional soil management, and (5) absence of incentives and regulations on soil management and their enforcement. All these shortcomings need to be addressed by advisors, scientists, and policy makers, whilst acknowledging the need for underpinning and differentiation of incentives and regulations.
Land use as a driver of soil fertility and biodiversity across an agricultural landscape in the Central Peruvian Andes
Valença, Anne W. De; Vanek, Steven J. ; Meza, Katherin ; Ccanto, Raul ; Olivera, Edgar ; Scurrah, Maria ; Lantinga, Egbert A. ; Fonte, Steven J. - \ 2017
Ecological Applications 27 (2017)4. - ISSN 1051-0761 - p. 1138 - 1154.
Andean forest - cropping systems - land use intensification - pasture - soil biology - soil degradation - soil macrofauna - vegetation
Land use change and intensification in agricultural landscapes of the Andean highlands have resulted in widespread soil degradation and a loss in soil-based ecosystem services and biodiversity. This trend threatens the sustainability of farming communities in the Andes, with important implications for food security and biodiversity conservation throughout the region. Based on these challenges, we sought to understand the impact of current and future land use practices on soil fertility and biodiversity, so as to inform landscape planning and management decisions for sustainable agroecosystem management. We worked with local communities to identify and map dominant land uses in an agricultural landscape surrounding Quilcas, Peru. These land uses existed within two elevations zones (low-medium, 3200-3800 m, and high elevation, 3800-4300 m). They included three types of low-medium elevation forests (eucalyptus, alder, and mixed/native species), five pasture management types (permanent pasture, temporal pasture [in fallow stage], degraded pasture, high-altitude permanent pasture, and high-altitude temporal pasture [in fallow stage]) and six cropping systems (forage crops, maize/beans, and potato under four types of management). Soil fertility was evaluated in surface soils (0-20 cm) with soil physicochemical parameters (e.g., pH, soil organic matter, available nutrients, texture), while soil biological properties were assessed using the abundance and diversity of soil macrofauna and ground cover vegetation. Our results indicated clear impacts of land use on soil fertility and biological communities. Altitude demonstrated the strongest effect on soil physicochemical properties, but management systems within the low-mid elevation zone also showed important differences in soil biological communities. In general, the less-disturbed forest and pasture systems supported more diverse soil communities than the more intensively managed croplands. Degraded soils demonstrated the lowest overall soil fertility and abundance of soil macrofauna, but this may be reversible via the planting of alder forests. Our findings also indicated significant covariation between soil physicochemical parameters, soil macrofauna, and ground vegetation. This suggests that management for any one of these soil properties may yield unintended cascading effects throughout the soil subsystem. In summary, our findings suggest that shifts in land use across the landscape are likely to have important impacts on soil functioning and biodiversity.
Vruchtbare gronden: Integrale bodemvisie & Bodembeoordeling en verbetering
Haan, Janjo de - \ 2015
arable farming - soil degradation - tillage - soil fertility - biodiversity - ecosystem management - soil-landscape relationships - soil water - fields - nematoda - soil surveys - rotations
December 2015. Projectnummer 3750313900
More food from fertile grounds: Integrating approaches in order to improve soil fertility
Beek, C.L. van; Duivenbooden, N. van; Noij, G.J. ; Heesmans, H.I.M. - \ 2014
Wageningen : Alterra
bodemvruchtbaarheid - teeltsystemen - bodemdegradatie - afrika ten zuiden van de sahara - mest - soil fertility - cropping systems - soil degradation - africa south of sahara - manures
Soils represent a major natural capital asset and have enormous potential to increase agricultural production while, at the same time, combating climate change and contributing to green economic growth. Yet, every year more than €3 thousand million is lost due to soil degradation. To unlock the potential of soils, nutrients need to be used more efficiently. This can be achieved by improving the recycling of nutrients, increasing organic matter content and applying fertilizers of the right type in the right amounts, at the right time and in the right place. There are several pathways of change that have been proposed to increase the productive capacity of soils. However, with current trends – globalization, urbanization, resource scarcity and climate change – new approaches are required. In our view, such approaches should be based on Integrated Soil Fertility Management (ISFM), which includes the application of both mineral fertilizers and organic manures. Subsequently, ISFM should be supplemented with site-specific interventions and a better match between supply and demand of (locally available) nutrients to make the best use of available resources, reduce environmental impacts and enhance green economic growth. The Fertile Grounds Initiative (FGI) was designed as an coordinated strategy of collaboration between actors in nutrient management at various spatial scales. It is based on eight subcomponents, which bring together the supply and demand of nutrients within a specific geographical area to make optimum use of site-specific interventions and available nutrients, supplemented with external imports. We expect the FGI to make a significant practical contribution to sustainable development in areas with limited soil fertility and nutrient availability, while at the same time resolving problems arising from nutrient excess in certain parts of the country and from (urban) waste streams, turning these into economic assets.
Zaaien op dorre bodem : wereldwijde aanpak van verwoestijning
Lynden, Godert van - \ 2013
land degradation - rehabilitation - soil degradation - soil conservation - world - desertification
Exploring opportunities for diversification of specialized tobacco farms in the Northwest of Argentina
Chavez Clemente, M.D. - \ 2012
Wageningen University. Promotor(en): Alfons Oude Lansink, co-promotor(en): Paul Berentsen. - S.l. : s.n. - ISBN 9789461734204 - 161
tabak - gespecialiseerde landbouw - gewasproductie - landbouwbedrijven - diversificatie - specialisatie - inkomen - risico - bodemdegradatie - argentinië - tobacco - specialized farming - crop production - farms - diversification - specialization - income - risk - soil degradation - argentina
In the Northwest of Argentina tobacco (Nicotiana tabacum L.) is economically and socially important. Tobacco mono-cropping, excessive tillage and inadequate irrigation management cause soil degradation. This and also tobacco production dependence on government subsidies and concern about health damage from tobacco consumption calls for research on diversification. The aim of this thesis was to explore opportunities for diversification of specialized tobacco farms in the Northwest of Argentina.
The Impact of First-Generation Biofuels on the Depletion of the Global Phosphorus Reserve
Hein, L.G. ; Leemans, R. - \ 2012
Ambio 41 (2012)4. - ISSN 0044-7447 - p. 341 - 349.
cumulative carbon emissions - dangerous climate-change - soil degradation - energy - environment - trends - cycle
The large majority of biofuels to date is “first-generation” biofuel made from agricultural commodities. All first-generation biofuel production systems require phosphorus (P) fertilization. P is an essential plant nutrient, yet global reserves are finite. We argue that committing scarce P to biofuel production involves a trade-off between climate change mitigation and future food production. We examine biofuel production from seven types of feedstock, and find that biofuels at present consume around 2% of the global inorganic P fertilizer production. For all examined biofuels, with the possible exception of sugarcane, the contribution to P depletion exceeds the contribution to mitigating climate change. The relative benefits of biofuels can be increased through enhanced recycling of P, but high increases in P efficiency are required to balance climate change mitigation and P depletion impacts. We conclude that, with the current production systems, the production of first-generation biofuels compromises food production in the future.
Risk assessment methodologies of soil threats in Europe: status and options for harmonization for risks by erosion, compaction, salinization, organic matter decline and landslides
Ano-Vidal, C. ; Ehlert, P.A.I. ; Hagyo, A. ; Heesmans, H.I.M. ; Kuikman, P.J. ; Oenema, O. ; Recatala-Boix, L. ; Simota, C. ; Tóth, G. ; Beek van, C. ; Akker van de, J. ; Zee, S.E.A.T.M. van der; Verzandvoort, S. - \ 2012
Luxembourg : Publications Office of the European Union (JCR scientific and technical reports ) - ISBN 9789279142918 - 84
risicoschatting - methodologie - bodemdegradatie - erosie - bodemverdichting - verzilting - organisch bodemmateriaal - aardverschuivingen - europa - risk assessment - methodology - soil degradation - erosion - soil compaction - salinization - soil organic matter - landslides - europe
The EU thematic strategy for soil protection recognizes that soil degradation through erosion, soil organic matter decline, compaction, salinization and landslides occurs in specific areas, and that these areas must be identified in an unequivocal way. Currently, there are various risk assessment methodologies (RAMs) and the question has risen to what extent these RAMs yield similar outcome and, if not, whether the outcome can be harmonized, i.e. whether the results of the various RAMs can be made compatible or comparable. In this study i) the current status of RAMs for erosion, soil organic matter decline, compaction, and salinization in the European Union (EU27) is reviewed, and ii) the need and the options for harmonization are assessed. The need for harmonization was defined as the likelihood of achieving different outcomes when using different RAMs, whereas the options for harmonization refer to the efforts that are required to harmonize soil RAMs. The current status of RAMSs in EU-27 was assessed on the basis of questionnaires, which were sent out to soil specialists and policy officers in all Member States. We received more than 100 (response rate >50%) completed questionnaires. It turned out that many of the so called RAMs are still incomplete; they are ‘process (or threat) quantifications’ rather than methodologies that assess the risk of a soil threat. Moreover, there were significant differences between RAMs for a soil threat in terms of (i) the notion of the threat, (ii) data collection, (iii) data processing, (iv) data interpretation, and (v) risk perception. The need for harmonization appeared highest for erosion and salinization, whereas the options for harmonization were best for SOM decline. Harmonization of soil RAMs may be very complex and for that reason not always feasible. We suggest two options that may facilitate unequivocal identification of risk (or priority) areas for soil threats, i) a two Tiered approach based on data availability and spatial scale and ii) generic harmonization, i.e. combining standardization and harmonization in a rather pragmatic way
Growing Sugarcane for Bioenergy – Effects on the Soil
Hartemink, A.E. - \ 2010
In: Proceedings 19th World Congress of Soil Science, Brisbane, Australia, 01 - 06 August, 2010. - - p. 13 - 15.
suikerriet - bodemdegradatie - verzuring - brandstofgewassen - uitspoelen - verliezen uit de bodem - verontreiniging - biobased economy - sugarcane - soil degradation - acidification - fuel crops - leaching - losses from soil - pollution - biobased economy
An increasing area of sugarcane is being growing for the production of bioenergy. Sugarcane puts a high demands on the soil due to the use of heavy machinery and because large amounts of nutrients are removed with the harvest. Biocides and inorganic fertilizers introduces risks of groundwater contamination, eutrophication of surface waters, soil pollution and acidification. This paper reviews the effect of commercial sugarcane production on soil chemical, physical and biological properties using data from the main producing areas. Although variation is considerable, soil organic C decreased in most soils under sugarcane and, also, soil acidification is common as a result of the use of N fertilizers. Increased bulk densities, lower water infiltration rates and lower aggregate stability occur in mechanized systems. There is some evidence for high leaching losses of fertilizer nutrients as well as herbicides and pesticides. Eutrophication of surface waters occurs in high-input systems. Sugarcane cultivation can substantially contribute to the supply of renewable energy, but that improved crop husbandry and precision farming principles are needed to sustain and improve the resource base on which production depends.
How good is GLASOD?
Sonneveld, B. ; Dent, D.L. - \ 2009
Journal of Environmental Management 90 (2009)1. - ISSN 0301-4797 - p. 274 - 283.
ordered logit model - soil degradation - land degradation - erosion - example - costs - gis
The Global Assessment of Soil Degradation (GLASOD) has been the most influential global appraisal of land quality in terms of environmental policy. However, its expert judgments were never tested for their consistency and could not be reproduced at unvisited sites, while the relationship between the GLASOD assessments of land degradation and the social and economic impact of that degradation remains unclear. Yet, other methodologies that Could respond to urgent calls for an updated assessment of the global environmental quality are not operational or, at best, in progress. Therefore, we evaluate the reliability and social relevance of the GLASOD approach and assess its candidacy for new global environmental assessments. The Study concentrates on the African continent, capitalizing on new GIS data to delineate and define the characteristics of GLASOD map units. Consistency is tested by comparing expert judgments on soil degradation hazard for similar combinations of biophysical conditions and land use. Reproducibility is evaluated by estimating an ordered logit model that relates the qualitative land degradation classes to easily available information on explanatory variables, the results of which can be used to assess the land degradation at unvisited sites. Finally, a cross-sectional analysis investigates the relation between GLASOD assessments and crop production data at sub-national scale and its association with the prevalence of malnutrition. The GLASOD assessments prove to be only moderately consistent and hardly reproducible, while the counter-intuitive trend with crop production reveals the complexity of the production-degradation relationship. It appears that increasing prevalence of malnutrition coincides with poor agro-productive conditions and highly degraded land. The GLASOD approach can be improved by resolving the differences in conceptualization among experts and by defining the boundaries of the ordered classes in the same units as independent, quantitative land degradation data
|Soil use and management
Hartemink, A.E. ; McBratney, A.B. ; White, R.E. - \ 2009
London [etc.] : Earthscan (Earthscan reference collections ) - ISBN 9781844076468 - 328
bodemkunde - bodembeheer - bodemdegradatie - bodemvruchtbaarheid - soil science - soil management - soil degradation - soil fertility
This four-volume set, edited by leading experts in soil science, brings together in one collection a series of papers that have been fundamental to the development of soil science as a defined discipline. Volume 3 on Soil Use and Management covers: - Soil evaluation and land use planning - Soil and water conservation - Soil fertility and plant nutrition - Soil engineering and technology - Soil degradation control, remediation and reclamation
Organic and conservation agriculture, the best of both worlds?
Sukkel, W. - \ 2008
In: ECOMIT: Proceedings of the 5th International Scientific Conference on Sustainable Farming Systems, Piestany, Slovakia, 5-7 November 2008. - Piestany : Slovak Association for Sustainable Agriculture - ISBN 9788096960316 - p. 14 - 16.
klimaatverandering - bodemdegradatie - biologische landbouw - organische stof - brandstofgewassen - koolstofvastlegging in de bodem - biobased economy - climatic change - soil degradation - organic farming - organic matter - fuel crops - soil carbon sequestration - biobased economy
In millions of years huge amounts of organic matter were stored in the soil as organic matter or fossil energy carriers as oil, gas and coal. We make use of these stocks to supply us with energy and to be able to grow plants for our needs. However what has been stored in our soils for millions of years we now are depleting in a few hundred years. The amount of organic matter we return back to the soil is in general too low to maintain its capacity for plant production on the long term. Various studies show there is a decrease of organic matter in arable soils all over the world.
Boomkwekerij en aardkunde in Nederland
Maas, G.J. ; Reuler, H. van - \ 2008
Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-werkdocument 113) - 32
boomkwekerijen - landbouwsector - landgebruik - bodemdegradatie - landschap - geomorfologie - forest nurseries - agricultural sector - land use - soil degradation - landscape - geomorphology
In opdracht van het Planbureau voor de Leefomgeving (PBL) is een verkennend onderzoek uitgevoerd naar het effect van de sector boomkwekerij op de kwaliteiten van het landschap die samenhangen met het reliëf en de bodem. De vraag in dit onderzoek is of er teeltmethoden in de boomkwekerij worden gehanteerd die een grotere impact hebben op bodem en reliëf dan algemeen landbouwkundig gebruik en die leiden tot het beschadigen of verdwijnen van aardkundige kwaliteiten, met name het reliëf.
Beyond the desertification narrative: a framework for agricultural drought in semi-arid East Africa
Slegers, M.F.W. ; Stroosnijder, L. - \ 2008
Ambio 37 (2008)5. - ISSN 0044-7447 - p. 372 - 380.
environmental crisis - soil degradation - land degradation - climate-change - stable states - burkina-faso - dry spell - management - rainfall - systems
In the 20th century, much research was done on desertification. Desertification developed into a complex and vague construct that means land degradation under specific conditions. Projects focusing on land degradation in semiarid East Africa have met with limited success because farmers prioritize drought as the major productivity-reducing problem. Yet studies on long-term rainfall trends have not confirmed that droughts are more frequent. In this article, we combine drought and land degradation effects into an Agricultural Drought Framework, which departs from the farmers' prioritization of drought and accommodates scientists' concern for land degradation. It includes meteorological drought, soil water drought, and soil nutrient drought. The framework increases insight into how different land degradation processes influence the vulnerability of land and farmers to drought. A focus on increased rainwater use efficiency will address both problems of land degradation and drought, thereby improving productivity and food security in semiarid East Africa.
Long-term global availability of food: continued abundance or new scarcity?
Koning, N.B.J. ; Ittersum, M.K. van; Becx, G.A. ; Boekel, M.A.J.S. van; Brandenburg, W.A. ; Broek, J.A. van den; Goudriaan, J. ; Hofwegen, G. van; Jongeneel, R.A. ; Schiere, J.B. ; Smies, M. - \ 2008
NJAS Wageningen Journal of Life Sciences 55 (2008)3. - ISSN 1573-5214 - p. 229 - 292.
voedselzekerheid - voedselprijzen - productiemogelijkheden - voedselvoorziening - honger - armoede - populatiegroei - biobrandstoffen - food security - food prices - production possibilities - food supply - hunger - poverty - population growth - biofuels - precision agriculture - use efficiency - climate-change - bioenergy production - developing-countries - economic-development - production systems - specialized dairy - green-revolution - soil degradation
During the 20th century hunger has become a problem of poverty amidst plenty rather than absolute food scarcity. The question is whether this will remain so or whether the hunger of the poor will once more be exacerbated by rising food prices. In this paper we discuss biophysical conditions, social forces and non-linear interactions that may critically influence the global availability of food in the long term. Until 2050, the global demand for primary phytomass for food will more than double, while competing claims to natural resources for other purposes (including biobased non-foods) will increase. A sober assessment of the earth¿s biophysical potential for biomass production, which recognizes competing claims and unavoidable losses, suggests that this is in itself still large enough for accommodating this rising demand. However, the exploitation of this biophysical potential proceeds through technical paradigms that set a relative maximum to food production. In addition, socio-economic mechanisms make the food economy run up against a ceiling even before this maximum is reached. As a consequence, current developments may well entail a new trend change in international markets. These developments include the depletion of land and water reserves, the stagnation of the potential yields of major crops, the rise in energy prices, and the way in which systemic socio-economic factors lead to a strong underutilization of production possibilities in the developing world. Given these conditions, the avoidance of steep rises in food prices may depend on the timely relaxation of socio-economic constraints in developing countries and on timely breakthroughs in sustainable yield increases, biorefinement and non-farm production systems. Myopic expectations make it doubtful whether spontaneous market forces will provide the necessary incentives for this, which may be reason for societal actors to consider the need for more active policies
The relation between geometry, hydrology and stability of complex hillslopes examined using low-dimensional hydrological models
Talebi, A. - \ 2008
Wageningen University. Promotor(en): P.A. Troch; Remko Uijlenhoet. - [S.l.] : S.n. - ISBN 9789085047889 - 120
landdegradatie - bodemdegradatie - heuvels - hellingen - topografie - stabiliteit - hydrologie - meetkunde - wiskundige modellen - land degradation - soil degradation - hill land - slopes - topography - stability - hydrology - geometry - mathematical models
Key words: Hillslope geometry, Hillslope hydrology, Hillslope stability, Complex hillslopes, Modeling shallow landslides, HSB model, HSB-SM model.
The hydrologic response of a hillslope to rainfall involves a complex, transient saturated-unsaturated interaction that usually leads to a water table rise. An increase of saturated groundwater flow can act as the triggering mechanism for slope failure. To account for the three-dimensional hillslope shape in which the groundwater flow and storage processes take place, simple (low-dimensional) but physically realistic models that represent hydrological processes at the hillslope scales are needed for reliable simulation of hillslope stability at the landscape scale. In this thesis the focus is on investigating the relation between hillslope geometry, hillslope hydrology and slope stability in complex hillslopes and hollows.
Several models have been presented in this thesis which examine the stability of nine characteristic hillslope types (landform elements) with three different profile curvatures (concave, straight and convex) and three different plan shapes (convergent, parallel and divergent). In addition to testing our models for nine characteristic hillslope types, a general relationship between plan shape and profile curvature of landform elements and the factor of safety is derived for a predefined hillslope length scale. Our results show that slope stability increases when profile curvature changes from concave to convex. In terms of plan shapes, changing from convergent to divergent, slope stability increases for all length profiles. Our analyses also show that the minimum safety factor occurs when the rate of subsurface flow is maximum. In fact, by increasing the subsurface flow, stability decreases for all hillslope shapes. Moreover, after a certain period of rainfall, the convergent hillslopes with concave and straight profiles become unstable faster than others whilst divergent convex hillslopes remain stable (even after intense rainfall). We also demonstrate that in hillslopes with non-constant soil depth (possible deep landslides), the ones with convex profiles and convergent plan shapes have slip surfaces with the minimum safety factor near the outlet region. Finally, we demonstrate that, in addition to bedrock slope, hillslope shape as represented by plan shape and profile curvature is an important control on hillslope stability.
With respect to the relation between rainfall occurrence and slope instability, a probabilistic model of rainfall-induced shallow landslides in complex hollows is also presented to investigate the relation between return period of rainfall, deposit thickness and landslide occurrence. A long term analysis of shallow landslides by the presented model illustrates that all hollows show a quite different behavior from the stability view point. Finally, we conclude that incorporating a more realistic description of hollow hydrology (the hillslope-storage Boussinesq model instead of the kinematic wave model) in landslide probability models is necessary, especially for hollows with a high convergence degree, which are more susceptible to landsliding. This model helps to theoretically investigate the relationship between return period of rainfall and landslide occurrence related to soil production (deposit thickness) in complex hollows.
In summary this thesis aims to understand theoretically how hydrological processes (subsurface flow and water table dynamics) affect slope stability in complex hillslopes and hollows. The presented models can widely be applied in many investigations of hillslope stability analysis because of their relative simplicity (low-dimensional).
Molendijk, L.P.G. ; Wolf, P.L. de; Breukers, M.L.H. - \ 2007
bodem - bodembescherming - bodemdegradatie - landgebruik - landbouwontwikkeling - landbouwbeleid - bodemkwaliteit - vergelijkend onderzoek - fytosanitair beleid - soil - soil conservation - soil degradation - land use - agricultural development - agricultural policy - soil quality - comparative research - phytosanitary policies
Toenemende wisselingen van gebruikers van grondpercelen (huurder, pachter) kunnen ertoe leiden dat er minder aandacht is voor bodemgezondheid. Daardoor bestaat het risico dat de basiskwaliteit van de Nederlandse percelen verslechtert. Dit staat haaks op het belang van de Nederlandse landbouw om zich een goede uitgangspositie in de vrije markt te verwerven door zich vooral toe te leggen op de teelt van uitgangsmateriaal met een hoge toegevoegde waard
Effecten van biomassaketens op landgebruik en bodemkwaliteit in Nederland : ontwikkeling van een toetsingskader
Hanegraaf, M.C. ; Molenaar, S.W. ; Elbersen, H.W. ; Annevelink, E. - \ 2007
Wageningen [etc.] : Nutriënten Management Instituut (Rapport / Nutri├½nten Management Instituut NMI 1183) - 56
landgebruik - duurzaamheid (sustainability) - biomassa - biomassa productie - bodemdegradatie - organisch bodemmateriaal - milieubeheer - bio-energie - bescherming - nederland - bodemkwaliteit - biobased economy - land use - sustainability - biomass - biomass production - soil degradation - soil organic matter - environmental management - bioenergy - protection - netherlands - soil quality - biobased economy
In opdracht van TCB (Technische Commissie Bodembescherming) heeft NMI een onderzoek uitgevoerd naar de mogelijke positieve en negatieve effecten van bio-energie op de bodemchemie.
Ecology of tree roots in substrates of The Hague
Arhipova, L. ; Spijker, J.H. ; Kopinga, J. - \ 2007
Wageningen : Alterra (Alterra-rapport 1590) - 111
wortels - straatbomen - stedelijke gebieden - groeimedia - rizosfeer - substraten - bodemdegradatie - kationenuitwisselingcapaciteit - waterafstotende gronden - hydrofobiciteit - nederland - zuid-holland - roots - street trees - urban areas - growing media - rhizosphere - substrates - soil degradation - cation exchange capacity - water repellent soils - hydrophobicity - netherlands - zuid-holland
The ecology of uniformly and non-uniformly distributed roots in layered and/or heterogeneous substrates, especially sand-peat-clay mixes, have been studied from literature and through a case study. There is a strong interaction between soil layering and/or heterogeneity and local root growth and local branching rate. In principle, the minimum area of root surface that a plant needs is very low. Real situations have much higher root surface areas for several reasons, one being the absence of synchronisation and synlocation of supply and demand of nutrients and water
Practice makes perfect: participatory innovation in soil fertility management to improve rural livelihoods in East Africa
Jager, A. de - \ 2007
Wageningen University. Promotor(en): Herman van Keulen; Ken Giller; Cees Leeuwis. - [S.l.] : S.n. - ISBN 9789085048428 - 218
bodemvruchtbaarheid - voedingsstoffenbalans - kringlopen - bodemdegradatie - bedrijfssystemenonderzoek - kleine landbouwbedrijven - boeren - oost-afrika - soil fertility - nutrient balance - cycling - soil degradation - farming systems research - small farms - farmers - east africa
Keywords: soil nutrient balances, soil fertility degradation, East Africa , participatory innovation, experiential learning, farmer field schools, smallholder agriculture
Maintaining and improving soil fertility is crucial for Africa to attain the Millennium Development Goals. Fertile soil and balanced soil nutrient management are major foundations for sustainable food production, contribute to a sound management of natural resources and assist in controlling environmental degradation such as erosion, loss of biodiversity, pollution of water sources and acidification. This thesis describes the development of an inter-disciplinary diagnostic tool to assess impacts of farm management practices on nutrient balances and the use of the tool in participative research and innovation approaches in East Africa over a ten-year period from 1995 to 2005.
The structured conceptual framework and related NUTMON approach facilitate a comprehensive description and analysis of management practices in complex smallholder farming systems. The approach has been successfully applied in a variety of projects addressing soil fertility degradation in Africa and Asia . A wide audience from both the research and development communities have been exposed to the approach. The integration of biophysical, financial and livelihood aspects in the analyses proved essential to assist effective decision making by farm households. The quantitative analysis based on farmers’ own data and observations, complements other participative tools and contributed to learning and innovation processes within households.
The various projects which implemented the approach showed that negative soil nutrient balances and high incidence of poverty prevail in most of the farming systems in East Africa . However, huge variations between geographical areas and individual farms were observed. Farmers often successfully integrated technical innovations in existing farm management systems, whereby combinations of application of organic manure and fertilizers appeared to be the most effective strategy. The research has shown that, once smallholders are equipped with knowledge and the capacity to learn, are empowered in organizations and connected to markets and the private sector, they can substantially improve their rural livelihoods. Therefore a focus on participatory experiential learning approaches and farmer organizations that result in new arrangements in innovation systems needs to be mainstreamed in rural development projects. Experiences show that the sustainability of group learning processes increases considerably when the groups engage successfully in commercial activities at the same time.
Innovations in soil fertility management were most successful and had the greatest impact on livelihoods in areas with both high agricultural potential and access to large urban markets. Investments in soil management or other technologies can be realised more easily by smallholders when they have opportunities to generate cash through commercial sales and value-addition, or when they have access to non-farm income. In more marginal areas most investments in inputs and technologies were financially unattractive or risky. In these areas priority needs be given to creating a more conducive environment for smallholders to do business and explore alternatives to food crop production.