36 research outputs found
Statut organique et microbiologique des sols dans des systÚmes agroforestiers et à jachÚre du Sénégal
RĂ©vision du genre Digitaria Haller (Poaceae) au SĂ©nĂ©gal : proposition dâune clĂ© de dĂ©termination pour une meilleure identification des espĂšces
Le genre Digitaria Haller (Poaceae) constitue lâun des genres les plus diversifiĂ©s des Poaceae du SĂ©nĂ©gal avec 19 espĂšces. Bien quâil y ait une monographie mondiale du genre, la dĂ©termination des espĂšces reste difficile et repose essentiellement sur les caractĂšres de lâappareil reproducteur. Ce travail, qui est une rĂ©vision du genre Digitaria au SĂ©nĂ©gal, est entrepris afin de rechercher des caractĂšres pertinents sur lâappareil vĂ©gĂ©tatif et dâamĂ©liorer lâidentification des espĂšces. Pour ce faire, une description dĂ©taillĂ©e des diffĂ©rents organes des spĂ©cimens Ă©tudiĂ©s est rĂ©alisĂ©e Ă lâaide dâune loupe binoculaire. Les rĂ©sultats de lâĂ©tude montrent que la pubescence de lâĂ©pillet est un caractĂšre essentiel pour lâidentification des espĂšces. De plus, les longueurs relatives de la glume supĂ©rieure et de la lemma infĂ©rieure sont trĂšs intĂ©ressantes pour la discrimination dâespĂšces affines. Toutefois, lâĂ©tude supplĂ©mentaire des organes vĂ©gĂ©tatifs de la plante adulte montre que certains caractĂšres vĂ©gĂ©tatifs pourraient contribuer considĂ©rablement Ă lâamĂ©lioration de lâidentification des espĂšces. Il sâagit du cycle biologique, de la pubescence de la ligule, de la marge du limbe, des noeuds et des entre-noeuds du chaume qui sont des caractĂšres plus faciles Ă observer. Une clĂ© de dĂ©termination basĂ©e sur des caractĂšres vĂ©gĂ©tatifs et reproducteurs des espĂšces est ainsi Ă©laborĂ©e.© 2015 International Formulae Group. All rights reserved.Mots clĂ©s: Digitaria, Poaceae, rĂ©vision, clĂ© de dĂ©termination, SĂ©nĂ©galEnglish Title: Review of Digitaria Haller (Poaceae) genus in Senegal: suggestion of a determination key for a better identification of speciesEnglish AbstractThe genus Digitaria Haller (Poaceae) is one of the most diversified genera of Poaceae in Senegal with 19 species. Although it has a worldwide monograph of the genus, the identification of species remains difficult and mainly based on the characteristics of the reproductive system. This work, which is a review of the genus  Digitaria in Senegal, is undertaken in order to search relevant characteristics on the vegetative system and to improve the identification of species. To do this, a detailed description of the various organs of the studied specimens is carried out using a binocular microscope. The results of the study show that the pubescence of the spikelet is an essential characteristic for the identification of species. Moreover, the relative lengths of the upper glume and lower lemma are very interesting for the discrimination of species closely related. However, the additional study of vegetative organs of the adult plant shows that some vegetative characteristics could contribute considerably to the improvement of the identification of species. It is the biological cycle, the pubescence of the ligule, the margin of the leaf blade, nodes and internodes of the thatch which are characteristics easier to observe. A key of determination based on vegetative and reproductive characteristics of species is thus worked out.© 2015 International Formulae Group. All rights reserved.Mots clĂ©s: Digitaria, Poaceae, review, key of determination, Senega
Village Baseline Study: Site Analysis Report for Kaffrine â Kaffrine, Senegal
The village baseline study of Toune MosquĂ©e village in the CCAFS benchmark site Kaffrine in Senegal took place from June 2 to 4, 2011. Natural resources in the village are in a progressive state of degradation. The âprotectedâ forest has almost disappeared, the soils have low fertility and are degraded, and crop production is not sufficient to meet the food needs of a family throughout the year. Families must buy food to fill the gap in production. For that they harvest and sell forest products, which creates a vicious cycle of resource degradation.
The male and female groups identified 35 organisations operating in the village including informal groups, state services, associations, NGOs and Muslim brotherhoods. While 18 of those work on food security issues, only 4 are involved in the management and protection of natural resources. Very few agricultural extension and training opportunities target women despite the womenâs significant role in agriculture and livestock production.
Women obtain information on livestock feeding techniques from people and organisations such as the horticultural project, womenâs associations, and water and forest services. Men get information on soil inputs and soil fertility management from other farmers, organisations, radio and television, and from community leaders, notably the office of the village chief and the mosque on Fridays. The radio is the form of media most commonly used by the women but few women own a radio
Chapitre 8. Dynamique de stockage du carbone dans les sols du Sénégal
Introduction Au Sénégal, la dynamique de stockage du carbone dans les sols est souvent estimée par des approches de modélisation (Tschakert et al., 2004 ; Parton et al., 2004 ; Woomer et al., 2004 ; Lufafa et al., 2008 ; Stoorvogel et al., 2009 ; DiÚye et al., 2012 ; Touré et al., 2013 ; Loum et al., 2014). Quelques études expérimentales ont également été réalisées (Elberling et al., 2003 ; Manlay et al., 2002 ; Masse et al., 2004). La teneur des sols en carbone est généralement faible, de mo..
Adaptation Actions in Africa: Evidence that Gender Matters
This paper presents the initial data analyses of the CCAFS gender survey implemented in four sites in Africa. Using descriptive statistics we show gender differences in terms of perceptions of climate change, awareness and adoption of climate smart agricultural (CSA) practices, and types and sources of agro-climatic information in the four sites.We find that both men and women are experiencing changes in long-run weather patterns and that they are changing their behaviours in response; albeit relatively minor shifts in existing agricultural practices. For example, the most prevalent changes reported include switching crop varieties, switching types of crops and changing planting dates. As expected, women are less aware of many CSA practices. Encouragingly, this same pattern does not hold when it comes to adoption; in many cases, in East Africa in particular, women, when aware, are more likely than or just as likely as men to adopt CSA practices. In West Africa, overall, the adoption of these practices was much lower. In addition, we see that access to information from different sources varies greatly between men and women and among the sites; however, promisingly, those with access to information report using it to make changes to their agricultural practices. Our findings suggest that targeting women with climate and agricultural information is likely to result in uptake of new agricultural practices for adaptation
Carbone des sols en Afrique
Les sols sont une ressource essentielle Ă prĂ©server pour la production dâaliments, de fibres, de biomasse, pour la filtration de lâeau, la prĂ©servation de la biodiversitĂ© et le stockage du carbone. En tant que rĂ©servoirs de carbone, les sols sont par ailleurs appelĂ©s Ă jouer un rĂŽle primordial dans la lutte contre lâaugmentation de la concentration de gaz Ă effet de serre. Ils sont ainsi au centre des objectifs de dĂ©veloppement durable (ODD) des Nations unies, notamment les ODD 2 « Faim zĂ©ro », 13 « Lutte contre le changement climatique », 15 « Vie terrestre », 12 « Consommation et production responsables » ou encore 1 « Pas de pauvretĂ© ». Cet ouvrage prĂ©sente un Ă©tat des lieux des sols africains dans toute leur diversitĂ©, mais au-delĂ , il documente les capacitĂ©s de stockage de carbone selon les types de sols et leurs usages en Afrique. Il propose Ă©galement des recommandations autour de lâacquisition et de lâinterprĂ©tation des donnĂ©es, ainsi que des options pour prĂ©server, voire augmenter les stocks de carbone dans les sols. Tous les chercheurs et acteurs du dĂ©veloppement impliquĂ©s dans les recherches sur le rĂŽle du carbone des sols sont concernĂ©s par cette synthĂšse collective. Fruit dâune collaboration entre chercheurs africains et europĂ©ens, ce livre insiste sur la nĂ©cessitĂ© de prendre en compte la grande variĂ©tĂ© des contextes agricoles et forestiers africains pour amĂ©liorer nos connaissances sur les capacitĂ©s de stockage de carbone des sols et lutter contre le changement climatique