Effet de la macrofaune et des modes de gestion de la fertilité sur le carbone d’un lixisol au Burkina Faso

La matière organique du sol est un élément déterminant de l’activité biologique, pour laquelle, la macrofaune du sol constitue un facteur important. Cette étude a été conduite pour appréhender les effets de la macrofaune et des modes de gestion de la fertilité des sols sur l’évolution du carbone d’un lixisol en zone semi-aride du Burkina Faso. Pour ce faire, un dispositif expérimental en split-plot à trois répétitions comprenant deux traitements principaux (parcelles avec et sans macrofaune) et quatre modes de gestion de la fertilité, a été mis en place. Les résultats ont montré que la macrofaune, les modes de gestion de la fertilité et leur interaction n’ont pas eu d’effet significatif (P > 0,05) sur le carbone total et l’indice de gestion du carbone à court terme. Toutefois, la macrofaune a augmenté l’indice de gestion du carbone de 35 % ; elle a également augmenté la teneur en carbone des différentes fractions granulométriques. L’interaction entre la macrofaune et les modes de gestion de la fertilité a amélioré le rendement du niébé. L’intensification écologique des agrosystèmes par un usage raisonné des pesticides chimiques de synthèse et un apport de matière organique, pourraient améliorer à long terme, la séquestration du carbone.Mots clés : Biologie des sols, séquestration du carbone, pesticides, Burkina Faso

The challenge of improving soil fertility in yam cropping systems of West Africa

Published online: 21 Nov 2017Yam (Dioscorea spp.) is a tuber crop grown for food security, income generation, and traditional medicine. This crop has a high cultural value for some of the groups growing it. Most of the production comes from West Africa where the increased demand has been covered by enlarging cultivated surfaces while the mean yield remained around 10 t tuber ha−1. In West Africa, yam is traditionally cultivated without input as the first crop after a long-term fallow as it is considered to require a high soil fertility. African soils, however, are being more and more degraded. The aims of this review were to show the importance of soil fertility for yam, discuss barriers that might limit the adoption of integrated soil fertility management (ISFM) in yam-based systems in West Africa, present the concept of innovation platforms (IPs) as a tool to foster collaboration between actors for designing innovations in yam-based systems and provide recommendations for future research. This review shows that the development of sustainable, feasible, and acceptable soil management innovations for yam requires research to be conducted in interdisciplinary teams including natural and social sciences and in a transdisciplinary manner involving relevant actors from the problem definition, to the co-design of soil management innovations, the evaluation of research results, their communication and their implementation. Finally, this research should be conducted in diverse biophysical and socio-economic settings to develop generic rules on soil/plant relationships in yam as affected by soil management and on how to adjust the innovation supply to specific contexts

Perceptions paysannes du changement climatique et strategies d’adaptation en riziculture pluviale de bas fond dans la region du Plateau Central du Burkina-Faso.: Farmer’s perceptions of climate change and adaptation strategies in lowland rainfed rice cultivation in the Central Plateau region of Burkina Faso.

Les changements climatiques et en particulier les évènements extrêmes, constituent une menace majeure pour la production agricole. Ses effets en riziculture pluviale sont la baisse des rendements et l’augmentation des importations. Cette étude a été conduite auprès de 101 producteurs dans 5 villages de la région du Plateau Central du Burkina Faso, afin d’analyser la compréhension de la perception paysanne du changement climatique ainsi que les stratégies mises au point par les producteurs de riz pluvial pour s’y adapter. Les résultats de l’étude indiquent que les producteurs ont conscience de ce que le climat a changé, l’impact le plus net en riziculture pluviale de bas-fonds étant la forte variation interannuelle, la modification du régime des vents, l'augmentation des poches de sècheresse entre juillet et septembre et les inondations fréquentes en mois d’août. Ces nouveaux défis ont conduit les riziculteurs à mettre aux points différents stratégies d’adaptation qui vont de la modification du calendrier cultural à la diversification des cultures. La mise en oeuvre de ces stratégies s’accompagne de changements importants au plan socioculturel, tels que l’introduction des travaux communautaires dans ces zones pour la mise en valeur des bas-fonds abandonnés il y’a de cela 20 ans. Dans ce contexte fait d’incertitudes et de mutations, des travaux de recherche sur la détermination de nouveaux calendriers culturaux et des méthodes de conservation des eaux des sols s’avèrent impératifs.ABSTRACT Climate change, and in particular extreme events, poses a major threat to agricultural production. Its effects in rain-fed rice farming are lower yields and increased imports. The study was conducted with 101 producers in 5 villages in the Central Plateau region of Burkina Faso to analyze the understanding of peasant perception of climate change and the strategies developed by rice producers to adapt to it. The results of the study indicate that producers are aware that the climate has changed, the net impact in low-lying rain rice farming is the high interannual variation, the change in the wind regime, the increase in between July and September and frequent flooding in August. These new challenges have led rice farmers to develop different adaptation strategies that range from changing the crop schedule to diversifying crops. The implementation of these strategies is accompanied by significant socio-cultural changes, such as the introduction of community work in these areas for the development of low-lying areas abandoned 20 years ago. In this context of uncertainty and mutation, research on the determination of new crop calendars and soil water conservation methods is imperative

Connaissance endogène de la classification et de la fertilité des sols en zone Sud-Soudanienne du Burkina Faso

Indigenous knowledge has been neglected by policy leaders and research for development. This study was carried out in October 2012 in two localities (Mahon and Diéri) located in the Kénédougou province (Burkina Faso). The aim was to valorize indigenous soil classification and soil fertility perception. We studied soil units along topographic units. The toposequences were selected according to geology and geomorphology. Soils classification was established in the field, based on semi structured interviews by using focus group method with tagba and sɛmɛ farmers. Visual method was used to describe topography, color, vegetation and tactile method was used to determine texture and coarse elements. The description was focused on the upper soil (0-20 cm) only. Soil composite samples were taken in the first 20 cm, to assess indigenous soil fertility perception. We found that soil classification criteria were based on topography and soil morphological characteristics and vegetation. Soils fertility was assessed on the basis of color and vegetation. In spite of a few minor variations in some soil qualities, soil physicochemical properties perception was consistent with laboratory results, proving tagba and sɛmɛ farmers had good knowledge on soil classification criteria

Connaissance endogène de la classification et de la fertilité des sols en zone Sud-Soudanienne du Burkina Faso

Indigenous knowledge has been neglected by policy leaders and research for development. This study was carried out in October 2012 in two localities (Mahon and Diéri) located in the Kénédougou province (Burkina Faso). The aim was to valorize indigenous soil classification and soil fertility perception. We studied soil units along topographic units. The toposequences were selected according to geology and geomorphology. Soils classification was established in the field, based on semi structured interviews by using focus group method with tagba and sɛmɛ farmers. Visual method was used to describe topography, color, vegetation and tactile method was used to determine texture and coarse elements. The description was focused on the upper soil (0-20 cm) only. Soil composite samples were taken in the first 20 cm, to assess indigenous soil fertility perception. We found that soil classification criteria were based on topography and soil morphological characteristics and vegetation. Soils fertility was assessed on the basis of color and vegetation. In spite of a few minor variations in some soil qualities, soil physicochemical properties perception was consistent with laboratory results, proving tagba and sɛmɛ farmers had good knowledge on soil classification criteria