Foliar inputs from indigenous agroforestry tree/shrub provide organic matter and nutrients to sustain crop production in the West African Sahelian region. This study aims at monitoring the decomposition and nutrients release of leafy biomass of selected agroforestry tree and shrub species. In Mali and Burkina Faso, fresh leaves were collected from leguminous trees (Faidherbia albida (Delile) A. Chev., Pterocarpus lucens Lepr.) and non-leguminous trees (Vitellaria paradoxa C.F. Gaertn., Khaya senegalensis (Desr.) A. Juss.) and in Senegal, fresh leaves were obtained from leguminous trees (Faidherbia albida (Delile) A. Chev., Pterocarpus lucens Lepr. and Piliostigma reticulatum (DC.) Hochst.) and the non-leguminous tree Guiera senegalensis J.F. Gmel. The leaf samples collected during the dry and rainy seasons were deployed for decomposition and nutrient release experiments using the litter bag technique. Average decomposition rate for this study was 0.23 k week− 1 whereby the rate of decomposition was 155
Acacia senegal (L.) Wild colonizes the Western Sahel of Mali. This agroforestry species plays an important role in the socio-economic life of local populations. The density of this species has declined sharply recently because of climate change and anthropogenic factors. However, the influence of this density on soil fertility has been documented in very few studies in Mali. This study reports the influence of the density of natural Acacia senegal stands on soil fertility. Three municipalities of the region (Gadiaba, Nioro, and Korokodjo) were selected for the study. At each site, three plots of 2500 m2 each were marked out. The Acacia woody stand within each plot was measured (basal circumference, total height, and circumference total height and circumference at 1.30 m). These measurements were preceded by an exhaustive inventory of the woody plants. Juvenile plants with a circumference of 10 cm were systematically counted and considered as regeneration. In parallel with these measurements, soil samples were taken from the tops and undersides of four-foot trees at the ends and centers of the plots. A 500 g composite sample was taken from these samples. These samples were sent to the Sotuba soil-water-plant laboratory for particle size and chemical analysis. Natural stands are very dense in Gadiaba, with an average of 690 plants/ha, medium density in Nioro, with 430 plants/ha, and very low density in Korokodjo, with 120 plants/ha. The natural stands in the study area are characterized by small, medium-diameter trees. At Gadiaba, the soil is sandy-loamy, while at Nioro and Korokodjo, the proportion of sand dominates at over 90%. The soils were all deficient in organic carbon, nitrogen, and assimilable phosphorus. Comparison of the magnesium content, sand, and silt proportions between the sites studied showed highly significant differences (p ˂ 0.001). The C/N ratios and phosphorus levels were not significantly different between the three sites. The C/N ratio is 4.55% at Gadiaba, 5.95% at Korokodjo and 3.36% at Nioro du Sahel. Phosphorus levels were 3.79% in Gadiaba, 1.73% in Korokodjo, and only 0.21% in Nioro du Sahel. For other mineral elements and pH, however, the differences are significant at the critical threshold of 5%. Therefore, it is important to identify suitable management methods for these resources.
Aims: The aim of this study was to assess the effect of plant extracts Azadirachta indica, Piper nigrum L, Acacia gummifera, Combretum micranthum, and Clenodium vulgare L on rice yellow mottle virus in rice. Study Design: The experiment was conducted in a Randomized Complete Block Design (RCBD) with five repetitions. The blocking factor was the sunshine. Place and Duration of Study: The study was carried out at the Microbiology and Microbial Biotechnology Research Laboratory (LaboREM-Biotech) of the Faculty of Sciences and Techniques, between June and November 2020. Methodology: The rice variety Kogoni91-1, which is highly susceptible to rice yellow mottle, was grown under greenhouse at the LaboREM-Biotech, inoculated with a highly virulent virus from the laboratory's collection and treated with plant extracts. Results: The results showed that rice plants treated with the combination of plant extracts from C. micranthum, A. indica, and C. vulgare recorded higher grain and aerial biomass yields than the positive control and very close to those of the negative control. Similarly, plants treated with black pepper extracts showed a number of spikelets, a yield and an aerial biomass higher than those of the positive control and very close to those of the negative control. Conclusion: Using plant extracts to combat rice yellow mottle could be an alternative to the application of chemical pesticides harmful to human and animal health.
Small mammals are regular inhabitants of urban centres worldwide. The house mouse Mus musculus and rats of the genus Rattus, major invasive alien species, are increasingly present, particularly in West Africa where house mice and black rats (Rattus rattus) are frequently met in commensal small mammal communities. We studied the case of Bamako the capital of Mali, through intensive city-wide trapping, and found a strong dominance of invasive alien species over native ones, with house mouse representing more than half and the brown rat (Rattus norvegicus) nearly one quarter of the captures. Shrews (Crocidura olivieri) and multimammate rats (Mastomys natalensis) represented the main native species still found in the city. The spatial and ecological determinants of these species’ distribution were analysed, showing segregation between species at different spatial scales. At the housing unit scale, M. musculus and M. natalensis appeared associated with inner parts of buildings, while R. norvegicus and C. olivieri occured at the interface between the indoor and outdoor environments. At the city scale, invasive species were more abundant in older quarters than in more recent peripheral ones. This was particularly true for the house mouse which probably colonized Bamako during the 21st century, while the brown and the black rats had done so a century before. This process of invasion of a native community of small mammals by cosmopolitan invasive species is discussed in a regional context, as are the potential consequences it may have in terms of public health and social well-being.
