Remineralization of a Dystric Ferralsol Using Basalt and Tephra Dusts, Effective Microorganisms Manure and NPK 20-10-10 for Radish (Raphanus sativus) Production in Bamougoum (Cameroon Western Highlands)

This paper studies the effect of basalt and tephra dusts, as alternatives to chemical fertilizers, on soil fertility and Radish (Raphanus sativus) production. The experiment was conducted in the field and in the laboratory in the years 2017 and 2018 on two separate plots so as to annul residual effects of fertilizers). The experimental design in the field was a randomized complete block design (56 m2 ), including five treatments and three replications: control (T0), basalt dust (T1), tephra dust (T2), effective micro-organism (EM) fertilizer (T3) and NPK 20-10-10 (T4). The main results show the following decreasing trend based on yield: T1>T3>T0>T4>T2. The best yields appear in T1 and T3 probably because they supplied the highest levels of soil nutrients to match the needs of the crops. Although T2 plants performed poorly, soil properties like pH.H2O (6.14 to 6.49), sum of exchangeable bases, base saturation, available phosphorus and cation balance were improved after tephra treatment. T2 plants might have performed poorly due to intrinsic properties of the tephra dust like low availability of trace elements compared to T1 and T3. T4 plants show the highest number of leaves, leaf area index and plant height. The Fe, Mn, Cu and Zn levels in bulbs and leaves will not pose danger of toxicity to human upon consumption and could serve as nutrient supplement for children and expectant mothers. The most profitable treatment is T1 permitting to recommend the popularization of basalt dust for radish cultivation as an alternative to chemical fertilizers

Tchabal Gangdaba Massif in the Cameroon volcanic line : a bimodal association

International audienc

Micronutrient Composition of Soils and Supported Solanum scabrum in Bafut Sub-division (North-West Cameroon)

Soil-plant metal interaction is vital in plant metabolism and on effects related to deficiency and toxicity, yet has received very little attention in terms of research in developing countries. The aim of the present study was to investigate the composition of Zn, Cu, Mn and Fe in soils and grown huckleberry (Solanum scabrum) in Bafut Sub-division (North-West Cameroon). Soils and huckleberry samples were collected in North and South Bafut in the rainy and dry seasons. The micronutrient levels in Solanum scabrum and soils were measured by Atomic Absorption Spectrometry. The results revealed that the metal levels of the soils were within the permissible range for agricultural soils. In the vegetables, only Fe and Mn, the most represented metals, were within the adequate and normal levels for optimum plant growth and human consumption, while Cu and Zn contents suggested a dietary intake deficiency for the inhabitants of the study area. The soil-metal transfer factors were globally less than 1 (0.03 to 0.95), lowest for Cu and highest for Fe. Between sites, Fe contents were fairly higher in South Bafut soils, while Zn, Mn and Cu were higher in North Bafut soils. These differences could be explained by the variation in the nature of parent rock in both localities and the slightly acidic soil pH which influences the solubility, mobility and bioavailability of soil nutrients. Between seasons, there was no significant difference (P<.05) between metal concentrations of soils and Solanum scabrum, except for Cu in the dry season vegetables. The present work suggests that S. scabrumcould serve as a cheaper source of micronutrients especially Fe and Mn for the local inhabitants of Bafut and beyond. &nbsp

Geohazards (floods and landslides) in the Ndop plain, Cameroon volcanic line

The Ndop Plain, located along the Cameroon Volcanic Line (CVL), is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually) and landslides (occasionally) occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people) tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide) maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered

Petrographic, morpho-structural and geophysical study of the quartzite deposit in the central part of Pouma, Littoral-Cameroon

The characterization of the Pouma-Cameroon quartzite deposit with the aim of determining its lateral extension along the Douala-Yaoundé axis required, among other things, the examination of the petrographic and morpho-structural domain as well as the determination of the electrical properties of the formations in the study area. 24 vertical electrical sounding points were carried out using a Schlumberger type electrode configuration; also, 7 manual auger boreholes were carried out, these resulted on one hand in the following types of curves: KH, QH, AKH, H, HK, AK, HA, A; and on the other hand to lithological logs with a clayey sandy texture, gravelly clayey sand to lateritic. The calculation of the densities as well as the petro-structural studies made it possible to confirm the geological context of the study area. The various results obtained permitted us to locate the fresh quartzite formation at the center of the study area. It stretches along the Douala-Yaoundé axis over 1871.4 m for the fresh formation and 1991 m for the slightly altered formation

The Pan-African post-collision Hosséré Mana plutonic complex and associated Gapi Stock (Western Cameroon Domain, Cameroon): Petrology, mineralogy and geochemistry

International audienceIn the Cameroon Pan-African orogenic belt, the West Cameroon Domain (WCD) is characterized by the apparent lack of Archean-Paleoproterozoic relicts, the development of Neoproterozoic basins and abundant plutonic massifs. The Hosséré Mana plutonic complex (HMPC) and the Gapi gabbroic stock are located in the vicinity of the Cretaceous Ngaou Boh granite complex and the Neogene Tchabal Gangbada basanite-trachyte-rhyolite volcanic plateau. They comprise clinopyroxene + amphibole ± olivine leucogabbro, clinopyroxene + amphibole monzogabbro, biotite + amphibole ± clinopyroxene monzodiorite, porphyritic and foliated biotite ± muscovite monzogranite. Two parallel trends of Mg#, displayed by leucogabbro (0.66–0.61) - monzogabbro (0.57–0.37), and by monzodiorite (0.66–0.55) -monzogranite (0.47–0.33), evidence two contrasting igneous suites, magnesian tholeiitic and magnesian high-K alkali-calcic to calc-alkaline (I-type). Primitive mantle-normalized patterns of the tholeiitic suite are fractionated, with no significant HFSE anomalies, suggesting a garnet-bearing enriched peridotite source. Primitive mantle-normalized patterns of the high-K alkali-calcic to calc-alkaline suite include more fractionated felsic types and display NbTa negative anomalies, suggesting another source with amphibole - garnet in the residue and possible origin of felsic rocks by partial melting of mafic lower crust with garnet and titanite-rutile in the residue. In leucogabbro, fairly low Sri (0.70538) and little negative εNd(750 Ma) (+0.2), with a TDM single-stage Nd model age of 1.42 Ga, are consistent with magmas extracted near the lithosphere – asthenosphere boundary from an enriched mantle source close to BSE (Bulk Silicate Earth). In monzodiorite, little higher Sri (0.70628) and strongly negative εNd(560 Ma) (−8.8), with a TDM single-stage Nd model age of 1.64 Ga, point to a supplementary (lithospheric?) mantle source metasomatized by subduction products. HMPC and GS massifs, emplaced in a syn-to post-kinematic environment after the major collision stage, illustrate coeval magnesian tholeiitic and magnesian high-K alkali-calcic calc-alkaline (I-type) igneous suites, in which primary magmas were tapped from different mantle sources, followed by younger felsic suite issued from garnet-bearing lower crustal source

Effect of Soil Geomechanical Properties and Geo-Environmental Factors on Landslide Predisposition at Mount Oku, Cameroon

In this work, we explored a novel approach to integrate both geo-environmental and soil geomechanical parameters in a landslide susceptibility model. A total of 179 shallow to deep landslides were identified using Google Earth images and field observations. Moreover, soil geomechanical properties of 11 representative soil samples were analyzed. The relationship between soil properties was evaluated using the Pearson correlation coe cient and geotechnical diagrams. Membership values were assigned to each soil property class, using the fuzzy membership method. The information value method allowed computing the weight value of geo-environmental factor classes. From the soil geomechanical membership values and the geo-environmental factor weights, three landslide predisposition models were produced, two separate models and one combined model. The results of the soil testing allowed classifying the soils in the study area as highly plastic clays, with high water content, swelling, and shrinkage potential. Some geo-environmental factor classes revealed their landslide prediction ability by displaying high weight values. While the model with only soil properties tended to underrate unstable and stable areas, the model combining soil properties and geo-environmental factors allowed a more precise identification of stability conditions. The geo-environmental factors model and the model combining geo-environmental factors and soil properties displayed predictive powers of 80 and 93%, respectively. It can be concluded that the spatial analysis of soil geomechanical properties can play a major role in the detection of landslide prone areas, which is of great interest for site selection and planning with respect to sustainable development at Mount Oku