Facteurs déterminants l’adoption des mesures de gestion intégrée de la fertilité des sols (GIFS) au nord du Bénin : une application du modèle probit multivarié au cas de producteurs de maïs

La baisse du niveau de fertilité des terres cultivables du fait des pratiques agricoles inadaptées, de la déforestation et du changement climatique reste l’une des contraintes majeures de l’agriculture béninoise. Les mesures de Gestion Intégrée de la Fertilité des Sols (GIFS) en sont une des approches de gestion durales des terres à l’échelle des exploitations agricoles. Ainsi, l’étude a fait usage d’un modèle probit multivarié pour identifier les déterminants de l’adoption des mesures de GIFS au sein des exploitations agricoles productrices de maïs au Nord-Bénin. Elle a été conduite sur un échantillon de 100 producteurs de maïs sélectionnés suivant un sondage aléatoire stratifié. Les résultats ont révélé l’existence d’une interdépendance et de complémentarités dans l’adoption des différentes mesures de GIFS. Aussi, la majorité des producteurs de maïs enquêtés préfèrent adopter une combinaison de deux mesures de GIFS (32%) ou de trois mesures (26%). Par ailleurs, la distance du village au champ, l’appartenance à un groupement, le contact avec la vulgarisation, la superficie  emblavée en maïs, la taille du cheptel et le nombre d’actifs agricoles restent les principaux facteurs déterminants l’adoption de ces mesures de GIFS par les producteurs.Mots clés : Bénin, changement climatique, gestion durable des terres, Gestion Intégrée de la Fertilité des Sols, pratiques agricoles, probit multivarié. English title: Adoption of integrated soil fertility management measures in northern Benin: an application of the multivariate probit model to the case of maize producers The decline in the level of fertility of arable land due to unsuitable agricultural practices, deforestation and climate change remains one of the major constraints of agriculture in Benin. Integrated Soil Fertility Management measures (GIFS) are one of the sustainable land management approaches that have been promoted at the level of farmers’ communities. Thus, the study made use of a multivariate probit model to identify the determinants of the adoption of GIFS measures within maize-producing farms in North Benin. It was carried out on a sample of 100 maize farmers selected following a stratified random survey. The results revealed the existence of interdependence and complementarities in the adoption of different GIFS measures. The majority of maize producers surveyed prefer to adopt a combination of two (32%) or three GIFS measures (26%). In addition, the distance from the village to the field, the membership of a group, the contact with the extension service, the area sown with maize, the size of the herd and the number of agricultural workers were identified as the important factors determining the adoption of these GIFS methods by producers.Keywords: Benin, climate change, sustainable land management, Integrated Soil Fertility Management measures, agricultural practices, multivariate probit

Dynamical Ising-like model for the two-step spin-crossover systems

In order to reproduce the two-step relaxation observed experimentally in spin-crossover systems, we investigate analytically the static and the dynamic properties of a two-sublattice Ising-like Hamiltonian. The formalism is based on a stochastic master equation approach. It is solved in the mean-field approximation, and yields two coupled differential equations that correspond to the HS fractions of the sublattices A and [email protected] ; [email protected]

Pressure and Temperature Spin Crossover Sensors with Optical Detection

Iron(II) spin crossover molecular materials are made of coordination centres switchable between two states by temperature, pressure or a visible light irradiation. The relevant macroscopic parameter which monitors the magnetic state of a given solid is the high-spin (HS) fraction denoted nHS, i.e., the relative population of HS molecules. Each spin crossover material is distinguished by a transition temperature T1/2 where 50% of active molecules have switched to the low-spin (LS) state. In strongly interacting systems, the thermal spin switching occurs abruptly at T1/2. Applying pressure induces a shift from HS to LS states, which is the direct consequence of the lower volume for the LS molecule. Each material has thus a well defined pressure value P1/2. In both cases the spin state change is easily detectable by optical means thanks to a thermo/piezochromic effect that is often encountered in these materials. In this contribution, we discuss potential use of spin crossover molecular materials as temperature and pressure sensors with optical detection. The ones presenting smooth transitions behaviour, which have not been seriously considered for any application, are spotlighted as potential sensors which should stimulate a large interest on this well investigated class of materials

Performance-Based Financing to Strengthen the Health System in Benin: Challenging the Mainstream Approach

Abstract Background: Performance-based financing (PBF) is often proposed as a way to improve health system performance. In Benin, PBF was launched in 2012 through a World Bank-supported project. The Belgian Development Agency (BTC) followed suit through a health system strengthening (HSS) project. This paper analyses and draws lessons from the experience of BTC-supported PBF alternative approach – especially with regards to institutional aspects, the role of demand-side actors, ownership, and cost-effectiveness – and explores the mechanisms at stake so as to better understand how the “PBF package” functions and produces effects. Methods: An exploratory, theory-driven evaluation approach was adopted. Causal mechanisms through which PBF is hypothesised to impact on results were singled out and explored. This paper stems from the co-authors’ capitalisation of experiences; mixed methods were used to collect, triangulate and analyse information. Results are structured along Witter et al framework. Results: Influence of context is strong over PBF in Benin; the policy is donor-driven. BTC did not adopt the World Bank’s mainstream PBF model, but developed an alternative approach in line with its HSS support programme, which is grounded on existing domestic institutions. The main features of this approach are described (decentralised governance, peer review verification, counter-verification entrusted to health service users’ platforms), as well as its adaptive process. PBF has contributed to strengthen various aspects of the health system and led to modest progress in utilisation of health services, but noticeable improvements in healthcare quality. Three mechanisms explaining observed outcomes within the context are described: comprehensive HSS at district level; acting on health workers’ motivation through a complex package of incentives; and increased accountability by reinforcing dialogue with demand-side actors. Cost-effectiveness and sustainability issues are also discussed. Conclusion: BTC’s alternative PBF approach is both promising in terms of effects, ownership and sustainability, and less resource consuming. This experience testifies that PBF is not a uniform or rigid model, and opens the policy ground for recipient governments to put their own emphasis and priorities and design ad hoc models adapted to their context specificities. However, integrating PBF within the normal functioning of local health systems, in line with other reforms, is a big challenge