Typologie et logique socio-économique des systèmes de culture associant céréales et légumineuses dans les agro-écosystèmes soudano-sahéliens du Burkina Faso

Dans la zone soudano-sahélienne du Burkina Faso, les associations mixtes céréales-légumineuses dominent les surfaces cultivées annuellement. Cependant, les rendements sont faibles et ne couvrent souvent pas les besoins alimentaires des exploitations qui les pratiquent. Afin d’améliorer la productivité de ces associations, il est nécessaire de comprendre la logique socio-économique de leurs mises en oeuvre. Dans cette optique, 60 exploitations agricoles familiales (EA) ont été enquêtées dans la région Nord du Burkina. Des analyses en correspondances multiples (ACM) font ressortir 4 types de systèmes de culture caractérisés d’une part par le niveau d’apport de matière organique et la fréquence de désherbage et d’autre part, par la présence de structures pérennes de conservation des eaux et des sols. La fertilisation organique et le désherbage fréquent sont associés aux EA les mieux pourvues en main d’oeuvre familiale, en petits ruminants et surfaces agricoles. L’âge de l’exploitant agricole et le nombre d’épouses sont de bons indicateurs des moyens économiques de l’EA. La plupart des recettes monétaires annuelles par EA varient dans la gamme très large de 25 à 300 KFCFA. Ces aspects doivent être pris en compte en vue de raisonner des propositions techniques adaptées à la diversité des EA de cette région.© 2016 International Formulae Group. All rights reserved.Mots clés: ACM, associations mixtes céréales-légumineuses, typologie des systèmes de culture, logique socioéconomique, Burkina FasoEnglish Title: Typology and socio-economic logic of cropping systems in Sub-Saharan agro-ecosystems of Burkina FasoEnglish AbstractIn Sub-Saharan zone of Burkina Faso, legumes and cereals mixed cultivation systems occupy most of the cultivated area. However, yields are low and often do not cover the food needs of farms that practise them. In order to improve the productivity of these intercropping systems, it is necessary to understand the socio-economic logic of their implementation. To this purpose, sixty family farms were surveyed in the northern region of Burkina Faso. Multiple correspondences analysis (MCA) showed four types of cropping systems characterized on one hand by the level of organic matter intake and weeding frequency and on the other hand, by the presence of permanent structures for water and soil conservation. Organic matter fertilization and frequent weeding are associated with farms with high family labor, livestock (especially small ruminants) and high cultivated area, while 70% of farmers have an off-farm activity. The age of household head and the number of their wives are good indicators of farmers’ income. Most of farmers’ monetary recipes vary widely from 25 to 300 KFCFA. These aspects must be taken into consideration for reasoning suitable technical recommendations for the farmer’s in this region.© 2016 International Formulae Group. All rights reserved.Keywords: MCA, legumes and cereals mixed cultivation systems, typology of cropping systems, socioeconomic logic, Burkina Fas

Use and management of biodiversity by smallholder farmers in semi-arid West Africa

Strategies that strengthen and use biodiversity are crucial for sustained food production and livelihoods in semi-arid West Africa. The objective of this paper was to examine the role of biodiversity in sustaining diverse forms of multifunctional farming practices while at the same time providing ecological services to subsistence-oriented farming families in the region of study through mechanisms as (a) crop species diversification, (b) management of spatial heterogeneity, and (c) diversification of nutrition-sensitive landscapes. Our analysis shows that crop associations between cereals and legumes or between perennials and annuals, have overall positive effects on soil characteristics and often improve crop yields. Soil heterogeneity is produced by woody perennials and termites. Local management provides opportunities to collect a diversity of nutrition-rich species year-round and sustain household nutrition.</p

Ramial wood amendments (Piliostigma reticulatum) mitigate degradation of tropical soils but do not replenish nutrient exports

Restoring degraded soils to support food production is a major challenge for West African smallholders who have developed local innovations to counter further degradation. The objective of this study was to evaluate a local farmer's technique that uses ramial wood (RW) as soil amendment (Piliostigma reticulatum shrub). Three treatments were applied in an experimental plot in Burkina Faso: control (no amendment), low RW (3 Mg fresh mass·ha−1·yr−1), and high RW (12 Mg fresh mass·ha−1·yr−1). RW was chipped to <5‐cm pieces and either buried or mulched. Topsoil carbon (C), nitrogen (N), and phosphorus (P) in control and low‐RW treatments declined after 7 years of continuous sorghum cultivation. Use of high‐RW amendment stabilized soil C content while N and P declined, thus not replenishing nutrient exports. Net contribution to soil C in the layer measuring 0–15 cm was 15% of the applied C in the high‐RW amendments. Although biomass and grain yields were higher in high‐RW treatments, crop productivity declined throughout the experiment for all treatments. Termite casts on RW treatments evidenced the potential role of wood‐foraging termites in diluting the impact of RW on soil fertility build‐up and soil water content. We conclude that mitigating soil degradation under semiarid conditions in Burkina Faso would require large amounts of woody amendments, particularly if the level of termite activity is high. Additional nutrient sources would be needed to compensate for removal in exported products so that biomass and grain production can be stabilized or increased.Estación Experimental Agropecuaria BarilocheFil: Félix, Georges F. Wageningen University. Farming Systems Ecology; HolandaFil: Clermont-Dauphin, Cathy. Montpellier SupAgro- Centre de Coopération Internationale en Recherche Agronomique pour le Développement-Institut National de la Recherche Agronomique. Eco&Sols; FranciaFil: Hien, Edmond. Laboratoire Mixte International. Intensification Ecologique des Sols Cultivés en Afrique de l'Ouest; Burkina FasoFil: Groot, Jeroen C.J. Wageningen University. Farming Systems Ecology; HolandaFil: Penche, Aurelien. Laboratoire Mixte International. Intensification Ecologique des Sols Cultivés en Afrique de l'Ouest; Burkina FasoFil: Barthès, Bernard G. Universidad Montpellier; FranciaFil: Manlay, Raphaël J. AgroParisTech; FranciaFil: Tittonell, Pablo Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Cournac, Laurent. Montpellier SupAgro- Centre de Coopération Internationale en Recherche Agronomique pour le Développement-Institut National de la Recherche Agronomique. Eco&Sols; Franci