Impact des techniques de conservation des eaux et des sols sur le rendement du sorgho au centre-nord du Burkina Faso

Face à la dégradation de leurs espaces vitaux, les populations du Burkina Faso en général, de la région de Dem en particulier, ont pris conscience de la nécessité d’enrayer ce fléau. Elles ont, seules ou avec l’appui des moyens techniques et financiers de l’État, des projets et des ONG, entrepris des travaux de conservation des eaux et des sols ainsi que d’agroforesterie. Après plus de deux décennies de pratiques, le paysage agraire de la région de Dem est aménagé en partie suivant différentes techniques : cordons pierreux, cordons d’Andropogon gayanus, paillage et zaï. Au cours de la campagne agricole 2002, des mesures ont été effectuées sur la croissance et le rendement du sorgho en fonction du type d’aménagement pratiqué. Tous les champs ont été choisis sur des topographies de bas glacis. Les résultats obtenus permettent d’affirmer que les techniques de conservation des eaux et des sols pratiquées dans la région de Dem sont bénéfiques pour les cultures et pour les communautés rurales. Les rendements de sorgho les meilleurs sont obtenus avec la pratique du zaï (1,730 t/ha), parce que cette technique allie fertilisation du sol par apport de compost ou de fumier et meilleure conservation de l’humidité après chaque pluie. Même le paillage qui, parmi les différentes techniques appliquées, donne les résultats les plus bas (0,77 t/ha), offre des rendements six fois supérieurs à ceux des parcelles sans aménagement (0,12 t/ha). L’impact positif des techniques de conservation des eaux et des sols sur le rendement du sorgho laisse entrevoir des possibilités d’accroissement de la production agricole, pour peu que les populations soient sensibilisées et que ces techniques soient améliorées pour une large diffusion auprès des paysans exploitant les mêmes types de sols, sous le même climat.Works of conservation of water and grounds and sorghum output in the Northern Center of Burkina Faso Face to the degradation of their vital spaces, the populations of Burkina Faso in general, area of Dem in particular became aware of the need for damming up the plague. They have, only or with the support of techniques of the State, the projects and ONG, undertaken work of conservation of water and grounds as well as the agroforestery. After more than two decades of practices, the agrarian landscape of the area of Dem still presents non made-up sectors; those arranged are it by various techniques: stony cords, cords of Andropogon gayanus, mulching, zaï. During the crop year 2002, measurements were taken on the growth and the output of the sorghum according to installations carried out. All the fields were selected on bottom glacis. The results obtained make it possible to affirm that the techniques of conservation of water and the grounds practised in the area of Dem are beneficial for the cultures and leaving for the populations. Indeed, the outputs are better with the practice of the zaï (1,730 t/ha), because this technique combines fertilization of the ground by contribution of compost or manure and conservation of moisture for one longer period after each rain. Even the mulching which, among the various techniques applied, gives the results low (0,77 t/ha), offers outputs six times higher than those of the pieces without installation (0,12 t/ha) on bottom glacis. The positive impact of the techniques of conservation of water and the grounds on the output of the sorghum shows the possibility to increase in the agricultural production, for little that the populations are sensitised and that these techniques are improved for a broad diffusion near the peasants exploiting the same types of grounds and under the same climate

Connaissance des OGMs et canaux d’information des acteurs au Burkina Faso

Pour subvenir aux besoins d’une population en croissance, les scientifiques proposent toujours de nouvelles technologies de production. Ces technologies ne sont pas toujours acceptées pour des raisons défendues par les groupes d’acteurs en présence. A la recherche de solutions pour améliorer la productivité agricole, les autorités du Burkina Faso se sont tournées vers l’utilisation des organismes génétiquement modifiés (OGM). L’étude vise à appréhender la connaissance des OGM et les principaux canaux d’information au Burkina Faso. Pour la réalisation de cette étude, une enquête a été conduite auprès de 272 personnes réparties dans 16 communes de trois provinces du Burkina Faso. L’étude a montré que sans discrimination du niveau d’instruction ou du genre, les acteurs ont une certaine connaissance des OGM. Les principaux canaux d’information sont le réseau d’encadrement des sociétés cotonnières (42%) et Internet (34%). Les réseaux d’encadrement sont effectifs dans la diffusion de l’information technologique. Dans la présente étude, il ressort que les technologies de communication sont efficaces pour une diffusion plus large.Mots clés : Burkina Faso ; OGM ; canaux d’information; niveau d’instruction

Accessibility to the drinking water sources in Burkina Faso: the case study of Toessin and Bonogo villages

In Africa, accessibility to drinking water is major problem for rural population. This study analyzes accessibility to the drinking water source in two villages in Burkina Faso. Data were obtained from household’s surveys. In total, 221 households have been surveyed. Data analysis method is based on water accessibility of World Health Organization & United Nations Children Fund (2017) and Howard & Bartram (2003) approach. Results show that in Toessin village, more than half of the households have improved service or intermediate access to wells, whereas a small percentage have access to boreholes. Slightly over half of the households have a low service or a minimal access for the same quantities of water and sources. No household falls under the limited service state or does not have access to wells, whereas small number of the families do not have access to boreholes. In the Bonogo village, nearly one third of households have improved service or intermediate access to boreholes and a very small number of household have intermediate access to wells. The majority of the Bonogo household’s access to boreholes fall under the basic service or a minimal access category, whereas accessibility to wells under the same category constitute slightly over half of the household. However, only a very small number of household in Bonogo have a limited service or do not have access at boreholes and wells. Overall, in terms of accessibility to drinking water sources, the majority of households in Toessin falls under the improved service or intermediate/minimal access for wells, whilst in Bonogo, most households fall under the basic service or minimal access to boreholes. It is necessary to dig new boreholes in Toessin in order to improve access to the drinking water

Perception locale de la dynamique du peuplement ligneux des vingt dernières années au Sahel burkinabé

Le Sahel ouest-africain a longtemps souffert de narrations négatives sur les tendances de son environnement depuis les sévères sécheresses des années 1970. Beaucoup de travaux antérieurs ont porté principalement sur les causes et les conséquences de la dégradation des écosystèmes. Au Burkina Faso, malgré l’existence de quelques études ethnobotaniques sur la dynamique de l’environnement au Sahel, la recherche sur la vision locale dans l’analyse de l’évolution de la végétation reste insuffisante. À travers des entretiens individuels menés auprès des populations locales, cette étude évalue leur perception de la dynamique du peuplement ligneux. Cent quatre-vingt-quatorze questionnaires ont été administrés dans trois villages situés au nord du pays. Les résultats montrent que dans l’ensemble, la majorité des enquêtés sont conscients et ont une très forte perception de l’évolution négative du couvert végétal de leur milieu. Quelques interviewés perçoivent une amélioration de la végétation avec une différence significative entre les trois villages sites. Il est donc nécessaire de prendre en compte ces diverses visions individuelles dans l’établissement des modes de gestion et pour la conservation durable des ressources naturelles.West African Sahel suffered negative narrations about its environmental dynamic since the 1970s drought. Many conducted researches were mainly based on drivers and impacts of ecosystems degradation. Despite some ethno-botanic studies on environment dynamic in the Sahel area of Burkina Faso, there is a gap of knowledge on farmers’ perceptions. Using a survey of 194 household, this study analyzes the perceptions of woody vegetation dynamic by farmers in three villages sites located in the sahelian zone of Burkina Faso. In general, results show that the majority of household perceive land cover degradation. Some of the respondents reported an increasing of vegetation cover with a statistically significant difference among the three study sites. Based on these results it is important to take into account individual perceptions to support the sustainability of the natural resources conservation and management

Multi-Temporal Landsat Images and Ancillary Data for Land Use/Cover Change (LULCC) Detection in the Southwest of Burkina Faso, West Africa

Accurate quantification of land use/cover change (LULCC) is important for efficient environmental management, especially in regions that are extremely affected by climate variability and continuous population growth such as West Africa. In this context, accurate LULC classification and statistically sound change area estimates are essential for a better understanding of LULCC processes. This study aimed at comparing mono-temporal and multi-temporal LULC classifications as well as their combination with ancillary data and to determine LULCC across the heterogeneous landscape of southwest Burkina Faso using accurate classification results. Landsat data (1999, 2006 and 2011) and ancillary data served as input features for the random forest classifier algorithm. Five LULC classes were identified: woodland, mixed vegetation, bare surface, water and agricultural area. A reference database was established using different sources including high-resolution images, aerial photo and field data. LULCC and LULC classification accuracies, area and area uncertainty were computed based on the method of adjusted error matrices. The results revealed that multi-temporal classification significantly outperformed those solely based on mono-temporal data in the study area. However, combining mono-temporal imagery and ancillary data for LULC classification had the same accuracy level as multi-temporal classification which is an indication that this combination is an efficient alternative to multi-temporal classification in the study region, where cloud free images are rare. The LULCC map obtained had an overall accuracy of 92%. Natural vegetation loss was estimated to be 17.9% ± 2.5% between 1999 and 2011. The study area experienced an increase in agricultural area and bare surface at the expense of woodland and mixed vegetation, which attests to the ongoing deforestation. These results can serve as means of regional and global land cover products validation, as they provide a new validated data set with uncertainty estimates in heterogeneous ecosystems prone to classification Errors

Perception locale de la dynamique du peuplement ligneux des vingt dernières années au Sahel burkinabé

West African Sahel suffered negative narrations about its environmental dynamic since the 1970s drought. Many conducted researches were mainly based on drivers and impacts of ecosystems degradation. Despite some ethno-botanic studies on environment dynamic in the Sahel area of Burkina Faso, there is a gap of knowledge on farmers’ perceptions. Using a survey of 194 household, this study analyzes the perceptions of woody vegetation dynamic by farmers in three villages sites located in the sahelian zone of Burkina Faso. In general, results show that the majority of household perceive land cover degradation. Some of the respondents reported an increasing of vegetation cover with a statistically significant difference among the three study sites. Based on these results it is important to take into account individual perceptions to support the sustainability of the natural resources conservation and management

MODIS NDVI trends and fractional land cover change for improved assessments of vegetation degradation in Burkina Faso, West Africa

Reduction of natural vegetation cover in the savannah of West Africa constitutes a pressing environmental concern that may lead to soil degradation. With the aim to assess the degradation of natural vegetation in the savannah of Burkina Faso, this study combined NDVI trends and fractional Land Use/Cover Change (LULCC). Fractional LULCC maps, derived from the aggregation of a 30 m Landsat LULCC map (1999–2011) to 250 m resolution of MODIS, were used to assess natural vegetation conversions in the small-scale spatial patterns of savannah landscapes. Mann-Kendall's monotonic trend test was applied to 250 m MODIS NDVI time series (2000–2011) to assess modifications of natural vegetation cover. Finally, the Spearman's correlation was employed to determine the relationship of natural vegetation degradation with environmental factors. The study revealed a vast conversion of natural vegetation into agriculture (15.9%) and non-vegetated area (1.8%) between 1999 and 2011. Significant decreasing NDVI trends (p < .05) indicated negative modifications of natural vegetation (2000–2011 period) occurring along the protected areas borders and in fragmented landscapes characterized by disruption of continuity in natural vegetation. Spearman's correlation showed that accessibility, climatic and topographic conditions favored natural vegetation degradation. The results can enable the development of efficient land degradation policies

La difficile territorialisation de la gestion de l’eau au Burkina Faso : une lecture au filtre de la théorie de la proximité

Our paper aims to analyze the modalities of coordination among local actors who are involved in integrated water resources management. So as to understand the dynamics of territorialization, we ground our analysis in the proximity framework to highlight that social and spatial relations around water resources are unbalanced. How this spatial inequality is taken into account may favor, or on the contrary, harm the sustainability of coordination. The approach in terms of proximity allows us to account for the complex articulation between the processes of territorial construction and the subsidiarity and participation principles presented as gage of IWRM success