4 research outputs found
Macrophytes Du Lac Iro Au Tchad : Diversité, Typologie Phytosociologique Et Pressions
Cette étude entreprise dans le lac Iro a portée sur l’estimation de la diversité macrophytique, l’identification des groupements végétaux, l’évaluation des potentielles menaces qui pèsent sur cette végétation et la détermination de la composition physico-chimique de l’eau. L’analyse des végétations a été faite par la technique des transects et la typologie des groupements végétaux par la méthode phytosociologique Braun-blanquetiste. L’estimation des indices de diversité et la discrimination des différents groupements végétaux ont été faites à l’aide du logiciel PAST. Plusieurs matériels ont été utilisés pour déterminer la qualité de l’eau. L’étude a permis de recenser 30 espèces reparties en 21 genres et 12 familles dont 96,42% d’Angiospermes et de 3,58% de Ptéridophytes. Les familles les mieux représentées sont les Poaceae, les Fabaceae et les Cyperaceae. Les espèces les plus fréquentes et présentes sur presque tous les transects sont : Echinochloa colona, Echinochloa stagnina, Neptunia oleracea, Ceratophyllum demersum et Pistia stratioites. Il a été distingué 6 groupements dont certains peuvent être intégrés dans des syntaxons existants dans d’autres écosystèmes lacustres. La qualité de l’eau est globalement favorable au développement des espèces aquatiques mais souvent polluée dans les parties très fréquentées. Les pressions qui s’exercent sur les phytocénoses du lac Iro témoignent de la vulnérabilité de cet écosystème.
This study in Lake Iro was focused on estimating macrophytic diversity, identifying plant groups, assessing potential threats to this vegetation, and determining the physico-chemical composition of water. Vegetation analysis was done by transect technology and plant group typology by the Braun-blanquetiste phytosociological method. The estimation of various diversity indices and the discrimination of different plant groups were made using the PAST software. Several materials were used to determine water quality. There were 30 species distributed among 21 genera and 12 families, of which 96,42% were Angiosperms and 3,58% were Pteridophytes. The best represented families were Poaceae, Fabaceae and Cyperaceae. The most frequent and present species on almost all transects were : Echinochloa colona, Echinochloa stagnina, Neptunia oleracea, Ceratophyllum demersum and Pistia stratioites. There were 6 groupings, some of which can be integrated into existing syntaxons in other lake ecosystems. Water quality was generally favorable to the development of aquatic species, but often polluted in areas of high frequency. Pressures on Lake Iro’s phytocenosis indicate the vulnerability of this ecosystem
Nodulation Responses of Four Food Crop Legumes to Cross-inoculation in the Guinea-savannah (Ngaoundere-cameroon) and Sudanian (Sarh-Chad) Zones
Abstract A cross-inoculation study on groundnut (Arachis hypogaea L.), bambara groundnut (Vigna subterranea L.), cowpea (Vigna unguiculata L.), and soybean (Glycine max L.) was carried out to screen potentially hight nodulating and nitrogen fixing Rhizobium strains suitable for important crops legumes in the Adamawa region (Cameroon) and middle-Chari region (Chad)
INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY Full Length Article Mycorrhiza-Rhizobium-Vigna subterranea Dual Symbiosis: Impact of Microbial Symbionts for Growth and Sustainable Yield Improvement
ABSTRACT Improvement of soil fertility and promotion of sustainable agriculture in Adamawa region is feasible if under-utilized crops such as bambara groundnut (Vigna subterranea) could be inoculated by Rhizobium and mycorrhiza strains in the field. An experiment was conducted in a completely randomized block design with five treatments; each of which was repeated thrice: control, Rhizobium, mycorrhiza, Rhizobium+mycorrhiza and chemical fertilizer. V. subterranea seeds used had a very high emerging capacity of between 92-100%. The soil organic matter was reduced by 20 to 30% after harvest, indicating their utilization for plant growth. Compared to un-inoculated plants, Rhizobium and mycorrhiza significantly (p ≤ 0.0007) increased nodulation and plant biomass at 30 and 60 DAP. The number of root nodules was reduced as from 50 days after planting, but increased in their dry weight, as an indication of their effectiveness to nodulation. The seed yield at harvest of Rhizobium+mycorrhiza treatment was boosted to three folds than that of control. Based on these results, it is suggested to prescribe the sustainable improvement of bambara groundnut production through Rhizobium+mycorrhiza inoculation