42 research outputs found
Linking up: The role of institutions and farmers in forage seed exchange networks of Southeast Asia
In Southeast Asia, access to improved forages remains a challenge for smallholder farmers and limits livestock production. We compared seed exchange networks supporting two contrasting livestock production systems to identify bottlenecks in seed availability and determine the influences of the market, institutions, and cultural context of seed exchange, using interview-based methods for âseed tracingâ and network analysis. Government agencies were the primary sources of high-quality genetic materials, with secondary diffusion in the Philippines dairy case being dominated by key individuals in active cooperatives. In the Vietnamese beef-oriented production context, farmer to farmer dissemination was more substantial. In both cases, formal actors dominated where botanical seed was exchanged, while farmers frequently exchanged vegetatively propagated materials among themselves. To improve access to forage seed in these contexts, government agencies and development actors should coordinate quality seed production upstream while supporting the creation of appropriate training, structures, and incentives for seed exchange network improvement downstream
Crop-livestock integration provides opportunities to mitigate environmental trade-offs in transitioning smallholder agricultural systems of the Greater Mekong Subregion
CONTEXT: The Greater Mekong Subregion has been undergoing rapid agricultural transformation over the last
decades, as traditional diverse subsistence-oriented agriculture is evolving towards intensified commercial
production systems. Negative environmental impacts often include deforestation, nutrient pollution, and
greenhouse gas (GHG) emissions.
OBJECTIVE: This study aims to explore the potential of crop-livestock integration to mitigate trade-offs between
economic and environmental impacts of smallholder farming systems at different stages of agricultural transition
and degrees of agricultural diversity across the Greater Mekong Subregion.
METHODS: We chose a âmiddle groundâ between detailed modeling of few, representative farming systems and
modeling of large household populations. 24 low and high diversity farms were selected in Laos (Xieng Khouang
province), Cambodia (Ratanakiri province) and Vietnam (Central Highlands) from a survey dataset of 1300
households. These farming systems were simulated with the whole-farm bio-economic and multi-objective
optimization model FarmDESIGN, calculating operating profit, GHG emissions and nitrogen (N) balance. Two
optimizations (âbusiness as usualâ vs. âcrop-livestock integrationâ) were performed, generating âsolution spacesâ or
alternative configurations aiming to maximize profitability, keep farm N balanced and minimize GHG emissions.
RESULTS AND CONCLUSIONS: Agricultural systems across the sites differed in their production orientation and
management practices, representing various stages of agricultural transition. Nitrogen balances varied between
sites, being negative in Ratanakiri (average 20.5 kg N ha 1 y 1) and Xieng Khouang ( 36.5 kg N ha 1 y 1) and
positive in the Central Highlands (73 kg N ha 1 y 1). Negative balances point to unsustainable mining of nutrients
due to sale of cash crops without sufficient inputs, and positive balances to the risk of environmental
contamination. Total GHG emissions ranged from 0.52â8.12 t CO2e ha 1 and were not significantly impacted by
stage of agricultural transformation or agricultural diversity. GHG sources in Ratanakiri and Xieng Khouang were
determined by crop residue burning while in Central Highlands fertilizer and livestock were main emitters. High
diversity farms obtained higher operating profits (10,379 USD y 1) than low diversity farms (4584 USD y 1).
Crop-livestock integration, a combination of measures including introduction of improved forages grasses,
manure recycling and residue feeding, and reduction of residue burning, resulted in larger âsolution spacesâ, thus
providing farmers with more options to mitigate agro-environmental trade-offs.
SIGNIFICANCE: These findings underline the potential of crop-livestock integration to support sustainable
intensification pathways in the Greater Mekong region. Public and private investment in further research and
extension is needed to develop and scale context-specific crop-livestock integration practices
Wave patterns generated by an axisymmetric obstacle in a two-layer flow
Gravity waves generated by a moving obstacle in a two-layer stratified fluid are investigated. The experimental configuration is three-dimensional with an axisymmetric obstacle which is towed in one of the two layers. The experimental method used in the present study is based on a stereoscopic technique allowing the 3D reconstruction of the interface between the two layers. Investigation into the wave pattern as a function of the Froude number, Fr, based on the relative density of the fluid layers and the velocity of the towed obstacle is presented. Specific attention is paid to the transcritical regime for which Fr is close to one. Potential energy trapped in the wave field patterns is also extracted from the experimental results and is analyzed as a function of both the Froude number, Fr, and the transcritical similarity parameter Î. In particular, a remarkable increase in the potential energy around Fr = 1 is observed and a scaling allowing to assemble data resulting from different experimental parameters is proposed
LivestockPlus: The sustainable intensification of forage-based agricultural systems to improve livelihoods and ecosystem services in the tropics
As global demand for livestock products (such as meat, milk, and eggs) is expected to double by 2050, necessary
increases to future production must be reconciled with negative environmental impacts that livestock cause. This
paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the
sustainable intensification of mixed cropâforageâlivestockâtree systems in the tropics by producing multiple social,
economic, and environmental benefits. Sustainable intensification not only improves the productivity of tropical
forage-based systems but also reduces the ecological footprint of livestock production and generates a diversity of
ecosystem services (ES), such as improved soil quality and reduced erosion, sedimentation, and greenhouse gas
(GHG) emissions. Integrating improved grass and legume forages into mixed production systems (cropâlivestock,
treeâlivestock, cropâtreeâlivestock) can restore degraded lands and enhance system resilience to drought and
waterlogging associated with climate change. When properly managed tropical forages accumulate large amounts
of carbon in soil, fix atmospheric nitrogen (legumes), inhibit nitrification in soil and reduce nitrous oxide emissions
(grasses), and reduce GHG emissions per unit livestock product.
The LivestockPlus concept is defined as the sustainable intensification of forage-based systems, which is based
on three interrelated intensification processes: genetic intensification â the development and use of superior
grass and legume cultivars for increased livestock productivity; ecological intensification â the development and
application of improved farm and natural resource management practices; and socio-economic intensification
â the improvement of local and national institutions and policies, which enable refinements of technologies
and support their enduring use. Increases in livestock productivity will require coordinated efforts to develop
supportive government, non-government organization, and private sector policies that foster investments and
fair market compensation for both the products and ES provided. Effective research-for-development efforts that
promote agricultural and environmental benefits of forage-based systems can contribute towards implemention of
LivestockPlus across a variety of geographic, political, and socio-economic contexts
Stereoscopic and velocimetric reconstructions of the free surface topography of antidune flows
Automatic Body Analysis For Mixed Reality
al time and allows one to interact in these input/output screens through natural gesture and speech. Transfiction systems are intended for intuitive interaction in a non-obtrusive manner, This work is supported by the Walloon Region under FIRST EUROPE Objectif 3 grant EPH3310300R0132/215069 and the grant CICYT TIC2001-0996 of the Spanish Government. 2 allowing one to develop a novel media and to offer users rich and engaging experiences. Figure 1: Transfiction concept. 2. System Implementation Figure 2: Typical Transfiction situations (background image on the left is CastermanSchuiten) . One of the peculiarities of the Transfiction system is the willingness to have it performing in real-time on standard PC architecture. Real-time is indeed mandatory in terms of design for users to enjoy the experience in settings using the magic mirror paradigm (cf. figure 2): achieved framerate after all treatments (from acquisition to rendering, including analysis) must be superior to 15 fps