Global efforts to foster sustainable soil management
Kessler, C.A. - \ 2018
soil management - soil fertility management
On the role of soil organic matter for crop production in European arable farming
Hijbeek, Renske - \ 2017
Wageningen University. Promotor(en): M.K. van Ittersum, co-promotor(en): H.F.M. ten Berge. - Wageningen : Wageningen University - ISBN 9789463436632 - 211
soil fertility - soil fertility management - soil management - soil conservation - organic matter - soil organic matter - nitrogen - nitrogen fertilizers - green manures - manures - straw - soil carbon sequestration - cover crops - crop yield - yields - meta-analysis - food security - europe - drivers - barriers - bodemvruchtbaarheid - bodemvruchtbaarheidsbeheer - bodembeheer - bodembescherming - organische stof - organisch bodemmateriaal - stikstof - stikstofmeststoffen - groenbemesters - mest - stro - koolstofvastlegging in de bodem - dekgewassen - gewasopbrengst - opbrengsten - meta-analyse - voedselzekerheid - europa - chauffeurs - barrières
The aim of this thesis was to improve understanding of the role of organic inputs and soil organic matter (SOM) for crop production in contemporary arable farming in Europe. For this purpose, long-term experiments were analysed on the additional yield effect of organic inputs and savings in mineral fertiliser. In addition, a farm survey was conducted to find drivers and barriers for the use of organic inputs and to assess if arable farmers in Europe perceive a deficiency of SOM.
The findings in this thesis suggest that at least on the shorter term, on average, there seems to be no immediate threat from a deficiency of SOM to crop production in arable farming in Europe. The long-term experiments showed that with sufficient use of only mineral fertilisers, on average, similar yields could be attained over multiple years as with the combined use of organic inputs and mineral fertiliser. This was reflected in the farm survey, in which a large majority of farmers indicated not to perceive a deficiency of SOM. Analysis of long-term experiments also showed that more mineral fertiliser N was saved when using farmyard manure at high N rates (with mineral fertiliser application) than at low N rates (without mineral fertiliser application), based on comparisons at equal yield.
Specific crops and environments did benefit from organic inputs and more SOM in terms of crop production. Long-term experiments showed that organic inputs give benefit to crop production in wet climates and on sandy soils. In addition, farmers perceived a higher deficiency of SOM on steep slopes, sandy soils, wet and very dry climates. The additional yield effect of organic inputs was significant for potatoes. More in general, farmers who cultivated larger shares of their land with specialized crops (including potatoes, sugar beets, onions and other vegetables) than cereals perceived a higher deficiency of SOM. It seems that while the functions of SOM can be replaced with technical means to a large extent (e.g. tillage, use of mineral fertilisers), there are limits to this technical potential when environmental conditions are more extreme and crops are more demanding.
The farm survey revealed that farmers perceive a trade-off between improved soil quality on the one hand and increased pressures from weeds, pests and diseases and financial consequences on the other hand when using organic inputs. If policies aim to stimulate the maintenance or increase of SOM, more insight is needed into the conditions that regulate the pressures of weeds, pests and diseases in response to organic inputs. Financial consequences (at least on the short term) should also be accounted for. More importantly however, benefits from SOM for crop production cannot be taken for granted. Only in specific situations such benefits will exist. If European policies on SOM aim to include benefits for crop production, focus should be on areas with more extreme environmental conditions (very dry or wet climates, steep slopes, sandy soils), or cropping systems with more specialized or horticultural crops rather than cereals.
Effecten bodem- en structuurverbeteraars : Onderzoek op klei- en zandgrond 2010-2015 eindrapportage
Balen, D.J.M. van; Topper, C.G. ; Geel, W.C.A. van; Berg, W. van den; Haas, M.J.G. de; Bussink, Wim ; Schoutsen, M.A. - \ 2016
Lelystad : Praktijkonderzoek Plant & Omgeving, onderdeel van Wageningen UR, Business Unit Akkerbouw, Groene Ruimte en Vollegrondsgroenten - 121
bodemkwaliteit - bodemstructuur - fysische bodemeigenschappen - chemische bodemeigenschappen - bodembiologie - bodemvruchtbaarheid - bodemvruchtbaarheidsbeheer - zware kleigronden - zandgronden - calciummeststoffen - biochar - soil quality - soil structure - soil physical properties - soil chemical properties - soil biology - soil fertility - soil fertility management - clay soils - sandy soils - calcium fertilizers - biochar
In de praktijk lopen telers vaak tegen problemen aan van een slechte bodemkwaliteit. Intensieve bouwplannen, steeds zwaardere mechanisatie, uitloging (Ca-uitspoeling), piekneerslagen en de schaalvergroting in de landbouw leiden tot vermindering van de fysische bodemvruchtbaarheid en de structuur van de bodem. Dit veroorzaakt: toenemende problemen bij de bewerkbaarheid van de bodem; minder efficiënt gebruik van meststoffen; verhoogd risico van uit- en afspoeling van nutriënten; wateroverlast; verlaging van de opbrengst. Om de bodemstructuur te verbeteren, worden door industrie en handel zogeheten bodemverbeteraars en kalkmeststoffen aangeboden. Er is een grote variatie in type producten, de wijze waarop ze werken en de mate waarin ze een directe dan wel indirecte invloed op de bodemvruchtbaarheid kunnen hebben. Objectieve informatie over het effect van deze producten op de gewasopbrengsten en de fysische, chemische en biologische bodemvruchtbaarheid ontbreekt. Uit eerdere proeven is bekend dat effecten van bodem verbeterende maatregelen vaak pas na enkele jaren zichtbaar worden. Om het effect van verschillende bodemverbeteraars op opbrengst en bodemeigenschappen op de langere termijn te toetsen, zijn proefvelden aangelegd op drie kleilocaties (Kollumerwaard, Lelystad en Westmaas) en twee zandlocaties (Vredepeel, Valthermond). Op deze proefvelden zijn bouwplannen toegepast die gangbaar zijn voor de betreffende regio. Eventuele positieve effecten worden sterker met het verstrijken der jaren. Bovendien zijn deze het duidelijkst te onderscheiden wanneer op alle locaties hetzelfde gewas wordt geteeld. Daarom stonden er in het laatste jaar op alle proefvelden aardappels. In de proef zijn de ontwikkeling van de gewasopbrengst, de gewaskwaliteit en de bodemeigenschappen gevolgd over een periode van zes jaar (2010-2015).
Tradeoffs around crop residue biomass in smallholder crop-livestock systems - What's next?
Tittonell, P.A. ; Gérard, B. ; Erenstein, O. - \ 2015
Agricultural Systems 134 (2015). - ISSN 0308-521X - p. 119 - 128.
sub-saharan africa - define conservation agriculture - soil fertility management - south-western niger - food-feed crops - ecological intensification - farming systems - impact assessment - appropriate use - 4th principle
Much has been written on the tradeoffs that smallholder farmers face when having to allocate their biomass resources among competing objectives such as feed, fuel, mulch, compost or the market. This paper summarises yet a new body of evidence from 10 studies on tradeoffs in the allocation of cereal crop residue biomass between soil management and livestock feeding in developing regions, published in the special issue of Agricultural Systems ‘Biomass use tradeoffs in cereal cropping systems: Lessons and implications from the developing world’. The studies cover a diversity of socio-ecological contexts, farming system types and scales of analysis. We reflect on their main findings and methodological progress, and on the new and not-so-new implications of these findings for research and action in the development agenda. We propose stylised graphical models to portray tradeoffs and plausible trajectories towards synergies, in the hope that such generalisations would prevent further efforts to ‘reinvent the wheel’ in the realm of tradeoffs analysis. We advocate an ex-post impact assessment of recent investments in systems research to help focus such research further and clearly define its future role in prioritizing and targeting development interventions.
Farm diversity, resource use efficiency and sustainable land management in the western highlands of Kenya
Mutoko, M.C. ; Hein, L.G. ; Shisanya, C.A. - \ 2014
Journal of Rural Studies 36 (2014). - ISSN 0743-0167 - p. 108 - 120.
soil fertility management - sub-saharan africa - technical efficiency - rural poverty - degradation - conservation - agriculture - impact - growth - maize
Sub-Saharan Africa (SSA) faces further population growth in the coming decades and it is essential to increase food production in rural areas. However, development programs to enhance agricultural productivity have achieved mixed results. This study investigates farm household responses to a changing agro-environment in one of the most densely populated rural districts in SSA and examines practical implications for the promotion of sustainable land management (SLM) practices. The specific objective is to analyze farm diversity and resource use efficiency and their implications for promoting SLM in the highlands of Western Kenya. We carried out an elaborate survey of 236 households, and applied multivariate analysis to analyze farm efficiency and livelihood strategies. We found major differences in responses to a changing agro-environment between five farm types in terms of resource endowment, income strategies and farm practices. Across farm types, efficiency was low indicating poor land productivity. Our study shows that there has been a lack of intensification in land use and that households are increasingly depending on off-farm income. Our findings have a number of implications to programs aiming to promote sustainable land management in SSA. We propose that successful implementation of such programs requires targeting areas highly reliant on agriculture and within these areas focus on households mostly dependent on farming to sustain their welfare. (C) 2014 Elsevier Ltd. All rights reserved.
Fostering technological transition to sustainable land management through stakeholder collaboration in the western highlands of Kenya
Mutoko, M.C. ; Shisanya, C.A. ; Hein, L.G. - \ 2014
Land Use Policy 41 (2014). - ISSN 0264-8377 - p. 110 - 120.
natural-resource management - agricultural input subsidy - soil fertility management - productivity - perceptions - experiences - knowledge
Application of sustainable land management (SLM) practices is essential to lessen the negative impacts of land degradation on rural welfare in sub-Saharan Africa. Scaling-up of SLM technologies requires collaboration of diverse stakeholders across multiple scales. We follow inter-disciplinary approaches to evaluate prospects for wider promotion of SLM practices in the western highlands of Kenya. Findings from this study reveal that only 10 per cent of farmers are properly implementing the available SLM practices. Agricultural productivity is low and there is high dependence on benefits extracted from the forest resource. A positive correlation (rho = 0.8) was found between stakeholder co-operation and success level of SLM projects. Results clearly show reasonable prospects such as some technology adoption activities and organisation of local actors that are necessary for triggering the transformation process to sustainable state of productivity. Nevertheless, technological transition could likely succeed if facilitated by enhanced stakeholder collaboration, a supportive policy environment and substantial resource mobilisation. We suggest the application of a context-specific transition management approach in this area in order to learn lessons on governance of transformative environmental programmes for similar socio-ecological systems in SSA. (C) 2014 Elsevier Ltd. All rights reserved.
Benefits of legume–maize rotations: Assessing the impact of diversity on the productivity of smallholders in Western Kenya
Ojiem, J.O. ; Franke, A.C. ; Vanlauwe, B. ; Ridder, N. de; Giller, K.E. - \ 2014
Field Crops Research 168 (2014). - ISSN 0378-4290 - p. 75 - 85.
soil fertility management - crop-livestock systems - on-farm productivity - soybean glycine-max - cattle manure - sustainable intensification - exploring diversity - semiarid kenya - degraded soils - nitrogen
Agricultural intensification of farming systems in sub-Saharan Africa is a prerequisite to alleviate rural poverty and improve livelihoods. Legumes have shown great potential to enhance system productivity. On-farm experiments were conducted in different agro-ecological zones (AEZ) in Western Kenya to assess the agronomic and economic benefits of promising legumes. In each zone, trials were established in fields of high, medium and low fertility to assess the effect of soil fertility heterogeneity on legume productivity and subsequent maize yield. Common bean, soybean, groundnut, lima bean, lablab, velvet bean, crotalaria, and jackbean were grown in the short rains season, followed by maize in the long rains season. Alongside, continuous maize treatments fertilised at different rates were established. AEZs and soil fertility gradients within these zones greatly affected crop productivity, returns to land and labour of rotations, as well as the relative performance of rotations. Poorer soil fertility and AEZs with lower rainfall gave smaller legume and maize yields and consequently, smaller returns to land and labour. The cultivation of legumes increased maize yields in the subsequent long rains season compared with continuous maize receiving fertiliser at a similar rate, while the increase of maize after green manure legumes was stronger than that after grain legumes. Maize yield responded strongly to increasing amounts of N applied as legume residues with diminishing returns to legume-N application rates above 100 kg N ha-1. In the low potential zones, factors other than improved N availability likely also stimulated maize yield. Rotations with grain legumes generally provided better returns than those with green manures. Intercropping bean with maize in the long rains season provided an additional bean yield that did not come at the expense of maize yield and improved returns to land and labour, but more so in the high potential zones. The results demonstrate the strong impact of biophysical diversity on the productivity of the legumes and suggest the need for careful targeting of legume technologies to the different biophysical conditions.
Integrated analysis of land use changes and their impacts on agrarian livelihoods in the western highlands of Kenya
Mutoko, M.C. ; Hein, L.G. ; Bartholomeus, H. - \ 2014
Agricultural Systems 128 (2014). - ISSN 0308-521X - p. 1 - 12.
soil fertility management - proximate causes - cover - deforestation - africa - sustainability - expansion - dynamics - district - growth
Land degradation is affecting rural livelihoods across sub-Saharan Africa. Promoting sustainable land management requires a thorough understanding of land use change drivers, processes and effects. However, in most African countries reliable data for such investigations are missing. We therefore test an integrated approach to analyse land use dynamics, combining remote sensing images, an in-depth quantitative survey, stakeholder interviews and local statistics. We analyse land dynamics and agricultural production over a 25-year period in Vihiga District, Western Kenya. Specifically, we examine how land use has changed in this period, the main drivers for land use change, and the main effects of these changes on agricultural production. Vihiga District is one of the most densely populated rural areas in Africa. We find that the district has undergone rapid land use change in the past 25 years. In particular, there has been a major conversion of forest and bare land to agricultural land use. Often, it is stated that increasing population pressure triggers agricultural intensification; however, we find little evidence of such a process in Vihiga District. Productivity of tea and, to a lesser extent, vegetables increased but the yields of maize and beans, the most common crops, fluctuated around a ton per hectare. Overall, per capita food crop production dropped by 28% during the past two decades. Our study shows that high and increasing population pressures do not necessarily lead to agricultural intensification, and that there is a need to consider more explicitly off-farm income in development and land management policies and projects.
Deconstructing and unpacking scientific controversies in intensification and sustainability: why the tensions in concepts and values?
Struik, P.C. ; Kuyper, T.W. ; Brussaard, L. ; Leeuwis, C. - \ 2014
Current Opinion in Environmental Sustainability 8 (2014). - ISSN 1877-3435 - p. 80 - 88.
soil fertility management - resource use efficiency - food security - agricultural sustainability - ecological intensification - sugar-beet - innovation - quality - systems - conservation
Assuming ‘ceteris paribus’ in terms of the viability of the planet during the coming half-century or so, the rising needs of a burgeoning, but also increasingly rich and demanding world population will drastically change agriculture. Crop yields and animal productivity will have to increase substantially, with the risk of further depleting the resource base and degrading the environment, making food production both the culprit and the victim. Future food security therefore depends on development of technologies that increase the efficiency of resource use and prevent externalization of costs. The current trend is towards intensification, especially more output per production unit so as to increase input efficiency. Whether that trend is sustainable is a matter of strong debate among scientists and policy-makers alike. The big question is how to produce more food with much fewer resources. Sustainable intensification (i.e., increasing agricultural output while keeping the ecological footprint as small as possible) for some is an oxymoron, unless real progress can be made in ecological intensification, that is, increasing agricultural output by capitalizing on ecological processes in agro-ecosystems. Definitions of intensification and sustainability vary greatly. The way these concepts are being used in different disciplines causes tensions and hides trade-offs instead of making them explicit. Inter-disciplinarity and boundary-crossing in terminology and concepts are needed. Implicitly, the operationalization of intensification and sustainability implies appreciation of and choices for values, an issue that is often overlooked and sometimes even denied in the natural sciences. The multidimensional nature of intensification needs to be linked to the various notions of sustainability, acknowledging a hierarchy of considerations underlying decision-making on trade-offs, thus allowing political and moral arguments to play a proper role in the strategy towards sustainable intensification. We make a plea to create clarity in assumptions, norms and values in that decision-making process. Acknowledging that win-win situations are rare and that (some) choices have to be made on non-scientific grounds makes the debate more transparent and its outcome more acceptable both to the scientific community and society at large.
Bemestingsplan verdient meer aandacht
Verloop, J. ; Abbink, G. ; Haan, M.H.A. de - \ 2014
V-focus 11 (2014)4. - ISSN 1574-1575 - p. 32 - 33.
melkveehouderij - mestbehoeftebepaling - graslandbeheer - zea mays - bodemvruchtbaarheidsbeheer - dairy farming - fertilizer requirement determination - grassland management - zea mays - soil fertility management
Resultaten van de KringloopWijzer laten grote verschillen zien in stikstof- en fosfaatopbrengsten, die op verschillende bedrijven worden bereikt in maïs- en grasland. Deels wordt dat veroorzaakt door de manier waarop de bemesting wordt uitgevoerd. Met perceelsgericht bemesten kan de potentie van het land meer worden benut.
The 'One cow per poor family' programme: Current and potential fodder availability within smallholder farming systems in southwest Rwanda
Klapwijk, C.J. ; Bucagu, C. ; Wijk, M.T. van; Udo, H.M.J. ; Vanlauwe, B. ; Munyanziza, E. ; Giller, K.E. - \ 2014
Agricultural Systems 131 (2014). - ISSN 0308-521X - p. 11 - 22.
soil fertility management - exploring diversity - resource-allocation - central highlands - western kenya - napier grass - agroforestry - productivity - variability - growth
Livestock is an essential component of smallholder farming systems in the East African highlands. The ‘One cow per poor family’ programme was initiated in Rwanda as part of a poverty alleviation strategy, aiming to increase the livestock population. A four month-study was conducted in Umurera village (Simbi sector), southern Rwanda with the objectives to (1) quantify the on-farm fodder availability, (2) quantify the amount and quality of fodder on offer to livestock, (3) analyse potential fodder availability under five future scenarios and (4) evaluate the implications and feasibility of the programme. Farmers’ surveys, measurements of field sizes, together with daily measurements of fodder on offer, milk production and fodder refusals were conducted. Feeds used were diverse, comprising grasses (53%), banana plant parts (25%), residues of several crops (9%) and other plants (10%). Herbs collected from valley-bottoms, uncultivated grasses and crop residues were predominant fodder types on poorer (Resource group 1 – RG1) farms while Pennisetum and Calliandra were predominant fodder types for moderate (RG2) and better resource endowed (RG3) farms. The amount of fodder on offer for cattle ranged from 20 to 179 kg fresh weight animal-1 day-1 (9–47 kg DM). The milk yield ranged between 1.3 and 4.6 L day-1. The amount of Pennisetum and Calliandra fodder available decreased in the dry season with a concomitant increase in reliance on banana leaves and pseudo-stems. The poorest farmers (RG1) were not able to feed a local cow under all scenarios. RG2 farmers can sustain a local cow during both seasons when using all possible fodder resources, but can sustain a European cow under just two scenarios during the rainy season. RG3 farmers can feed a European cow during the rainy season under all scenarios and for four scenarios during the dry season. We conclude that the ‘One cow per poor family’ programme needs to be adjusted to increase its effectiveness. Our main recommendations are to shift to livestock that require less fodder, for example local cattle or small ruminants such as goats.
Livelihood strategies, resilience and transformability in African agroecosystems
Tittonell, P.A. - \ 2014
Agricultural Systems 126 (2014). - ISSN 0308-521X - p. 3 - 14.
soil fertility management - social-ecological systems - western kenya - exploring diversity - makanya catchment - smallholder farms - poverty traps - heterogeneity - agriculture - tanzania
Aiming to translate resilience thinking theory into farming systems design practice, this paper examines fundamental properties of complex systems dynamics and their relation with the mechanisms that govern resilience and transformability in African smallholder agriculture. Agroecosystems dynamics emerge from the aggregation of diverse livelihood strategies in response to changes in the agroecosystem context, and are characterised by non-linearity, irreversibility, convergence/divergence and hysteresis. I examine a number of case studies from Africa to verify three guiding hypotheses in connection to the diversity of rural livelihood strategies: (1) diversity as alternative system regimes; (2) diversity as the result of transformability; (3) diversity determined by changing agricultural contexts. The hierarchy of constraints that determine the space for manoeuvring in agroecosystems is described through the analogy of the Matryoshka nesting dolls: each system level confines and is confined by their immediate sub- and supra-systems. Agricultural contexts, as defined by agro-ecological potential, demography and market connectivity are also dynamic and their trajectory can be described as shifts across stability domains. An example from Kenya shows that household diversity can be described as alternative system regimes, through hysteretic rather than continuous, reversible models. In some particular cases diversity emerges from divergent pathways that may have implied radical transformations in the past, as shown here for rural livelihoods in northern Cameroun. A comparative analysis of East African agroecosystems shows that thresholds in specific variables that may point to the existence of possible tipping points are rather elusive and largely site specific, requiring systematic categorisation of agricultural contexts. While agroecology needs to provide the knowledge base for the ecological intensification of smallholder landscapes, policy and market developments are needed to deal with the Matryoshka effect – or with interactions that are presumably panarchical in certain cases. Desirable shifts in farming systems can only be stimulated by working on both ends simultaneously.
Regenwormen op het melkveebedrijf : handreiking voor herkennen, benutten en managen
Eekeren, N.J.M. van; Bokhorst, J. ; Deru, J. ; Wit, J. de - \ 2014
Driebergen : Louis Bolk Instituut (Rapport / Louis Bolk Instituut 2014-004 LbD) - 37 p.
aardwormen - bodemkwaliteit - bodemvruchtbaarheid - bodemvruchtbaarheidsbeheer - melkveehouderij - bodembiologie - graslanden - bouwland - graslandbeheer - earthworms - soil quality - soil fertility - soil fertility management - dairy farming - soil biology - grasslands - arable land - grassland management
In deze brochure worden handreikingen gegeven voor de praktijk, waarbij zowel strooiselbewonende, bodembewonende en pendelende regenwormen aan bod komen.
Elferink, E. ; Alterra - Centrum Landschap, - \ 2014
bodemvruchtbaarheid - bodemvruchtbaarheidsbeheer - bodemkwaliteit - bio-energie - voedingsstoffen - mineralenboekhouding - biobased economy - soil fertility - soil fertility management - soil quality - bioenergy - nutrients - nutrient accounting system - biobased economy
In opdracht van Rijksdienst voor Ondernemend Nederland hebben Alterra en CLM de meetlat BioESoil ontwikkeld. BioESoil geeft inzicht in: verliezen van nutriënten tijdens de productie van bioenergie, de potentiele terugvoer van nutriënten middels residuen en het effect op de bodem organische stof. De meetlat is zo ontworpen dat deze gebruiksvriendelijk is van opzet. BioESoil is wereldwijd toepasbaar en geschikt voor grootschalige en kleinschalige bio-energie producenten en gebruikers.
Agriculture and nature: Trouble and strife?
Baudron, F. ; Giller, K.E. - \ 2014
Biological Conservation 170 (2014). - ISSN 0006-3207 - p. 232 - 245.
soil fertility management - agri-environment schemes - land-use change - biodiversity conservation - habitat fragmentation - food-production - tropical conservation - farmland biodiversity - protect biodiversity - organic agriculture
Global demand for agricultural products is expected to double in the next decades, putting tremendous pressure on agriculture to produce more. The bulk of this increase will come from developing countries, which host most biodiversity-rich areas of the planet. Whilst most biodiversity is found in production landscapes shared with people, where agriculture represents an increasing threat, international conservation organisations continue to focus on the maintenance and expansion of the network of protected areas. When conservation organisations partner with agricultural programmes, they promote low input, extensive agriculture. Combined with the focus on protected areas, this may exacerbate rather than mitigate conflicts between biodiversity conservation and agricultural production. Two models have been proposed to increase agricultural production whilst minimising the negative consequences for biodiversity: ‘land sparing’ and ‘land sharing’. Although often polarized in debates, both are realistic solutions, depending on the local circumstances. We propose a number of criteria that could guide the choice towards one or the other. We conclude that general principles to be considered in both land sparing and land sharing are: managing spillover effects, maintaining resilience and ecosystem services, accounting for landscape structure, reducing losses and wastes, improving access to agricultural products in developing countries and changing consumption patterns in developed countries, and developing supportive markets and policies.
Whole-farm nitrogen cycling and intensification of crop-livestock systems in the highlands of Madagascar: An application of network analysis
Alvarez, S. ; Rufino, M.C. ; Vayssières, J. ; Salgado, P. ; Tittonell, P.A. ; Tillard, E. ; Bocquier, F. - \ 2014
Agricultural Systems 126 (2014). - ISSN 0308-521X - p. 25 - 37.
soil fertility management - nutrient balances - exploring diversity - efficiencies - resource - manure - flows - kenya - conservation - agriculture
Food insecurity, soil fertility depletion and strong competition for biomass are commonly observed in smallholder crop-livestock systems. The objective of this study was to explore options to improve farm-level nitrogen cycling, productivity and economic performance through the analysis of N flows within four contrasting crop-livestock farm systems of Madagascar highlands. Farms were conceptualized as networks where the compartments were the household and their farming activities, all connected by N flows. Indicators assessing network size and cycling, and the organization and diversity of the N flows, were compared with system productivity, food self-sufficiency, and gross margins for the current situation and under four scenarios of intensification (i) dairy production increased by increasing N inputs as supplementary feed; (ii) crop production increased by increasing N inputs as mineral fertilizer; (iii) manure management improved to increase N conservation during storage and application to soils; (iv) a combination of the two most economically attractive scenarios (i and iii). The four case study farms represent local diversity differing widely in terms of network size, with total annual system N throughput ranging from 113 to 1037kgN per capita, and in terms of N cycling, from 3 to 41kgN per capita per year. They differed less in terms of external dependence, from 0.26 to 0.41kgN kgN-1. Improving N conservation through improved manure management (scenario iii) had a positive impact on gross margin, and this in combination with increased concentrate supply (scenario iv) led to increases in whole-farm N use efficiencies from 2% to 50%, in N cycling from 9% to 68% and in food self-sufficiency from 12% to 37% across farm types. Gross margin was the most sensitive indicator to changes in management. Intensification through scenario iv had the highest impact on farm productivity, gross margin, food self-sufficiency, and environment sustainability (N use efficiency, capacity of the soil to stock N)
Farmers' Perceptions of Land Degradation and their Investments in Land Management: a Case Study in the Cental Rift Valley of Ethiopia
Adimassu, Zenebe ; Kessler, A. ; Yirga, C. - \ 2013
Environmental Management 51 (2013)5. - ISSN 0364-152X - p. 989 - 998.
soil fertility management - conservation practices - nutrient balances - tenure security - south wello - highlands - adoption - smallholders - erosion - area
To combat land degradation in the Central Rift Valley (CRV) of Ethiopia, farmers are of crucial importance. If farmers perceive land degradation as a problem, the chance that they invest in land management measures will be enhanced. This study presents farmers’ perceptions of land degradation and their investments in land management, and to what extent the latter are influenced by these perceptions. Water erosion and fertility depletion are taken as main indicators of land degradation, and the results show that farmers perceive an increase in both indicators over the last decade. They are aware of it and consider it as a problem. Nevertheless, farmers’ investments to control water erosion and soil fertility depletion are very limited in the CRV. Results also show that farmers’ awareness of both water erosion and soil fertility decline as a problem is not significantly associated with their investments in land management. Hence, even farmers who perceive land degradation on their fields and are concerned about its increase over the last decade do not significantly invest more in water erosion and soil fertility control measures than farmers who do not perceive these phenomena. Further research is needed to assess which other factors might influence farmers’ investments in land management, especially factors related to socioeconomic characteristics of farm households and plot characteristics which were not addressed by this study.
Maismoeheid bestrijden met vruchtwisseling
Groten, Jos - \ 2013
zea mays - dairy farming - arable farming - soil fertility management - soil fertility - cropping systems - rotations - soil quality - green manures
Can we define the term 'farming systems'? A question of scale : Guest Editorial
Giller, K.E. - \ 2013
Outlook on Agriculture 42 (2013)3. - ISSN 0030-7270 - p. 149 - 153.
soil fertility management - smallholder farms - exploring diversity - resource-allocation - western kenya - land-use - variability - methodology - space
Participatory trials and farmers' social realities: understanding the adoption of legume technologies in a Malawian farmer community
Pircher, T. ; Almekinders, C.J.M. ; Kamanga, B.C.G. - \ 2013
International Journal of Agricultural Sustainability 11 (2013)3. - ISSN 1473-5903 - p. 252 - 263.
soil fertility management - africa - poverty - improvement - lessons - crop
This article presents results from a study exploring the reasons for low adoption of legume technologies to improve soil fertility by farmers from a community in central Malawi who took part in participatory trials. This study explores the influence of gender roles in agriculture and land ownership and socio-economic differentiation in the community. Because most women do not own land and are traditionally responsible for legume crops, they have little interest in managing soil fertility for maize crops. Men are not interested in using legumes in maize-cropping systems. Some are too poor: this group needs to complement their subsistence maize production with paid labour on the farms of better-off farmers; restricting the labour availability for their own farming activities. Wealthier farmers have access to, and prefer to use chemical fertilizer and cattle manure. Take-up rates among the middle group of farmers were also low. This study discusses how these (and other) factors influence the (non-)adoption of maize-legume technologies in Malawi and the effectiveness of participatory research. It emphasizes how differentiated farmer-realities affect the uptake of technologies identified as promising in participatory field evaluations.