Morphological, mineralogical and geochemical features of topomorphic vertisols used for sorghum production in North Cameroon

Authors : Simon Djakba BASGA, Jean Pierre TEMGA, Désiré TSOZUÉ, Nicodème DANBÉ, Jean Pierre NGUETNKAM

Pages : 346-354

Doi:10.18393/ejss.460841

View : 72 | Download : 15

Publication Date : 2018-10-01

Article Type : Research Paper

Abstract :In the present study, two topomorphic vertisols profiles used for sorghum production were described and characterized. After macroscopic characterization, physicochemical, mineralogical and geochemical analyses were made. Physicochemical analyses were made by standard methods while mineralogy was determined on clay fraction insert ignore into journalissuearticles values(˂2µm); by X-ray diffraction coupled to Fourier transform infrared spectroscopy. Geochemical analysis was determined on 180µm fraction by inductively coupled plasma- Atomic Emission Spectroscopy insert ignore into journalissuearticles values(ICP-AES); and mass spectrometry insert ignore into journalissuearticles values(ICP-MS);. Results revealed that studied vertisols were average deep, less differentiated with desiccations cracks and gilgai micro relief. The angular blocky structure and clayey texture were observed. They were alkaline insert ignore into journalissuearticles values(7.3 ≤ pH water ≤ 8.4); and recorded a low to moderate organic matter and nitrogen contents. Cation exchange capacity was high reaching 52.24 meq 100g -1 and exchangeable cations were moderates with Ca 2+ insert ignore into journalissuearticles values(3.69- 29.6 meq 100g -1 ); the most represented cation. Vertisols were made of smectites associated to kaolinite and a lesser content of quartz. Illites and calcite were also identified in some horizons. On the geochemical point of view, Si02 insert ignore into journalissuearticles values(55.87- 83.64%);, Al 2 O 3 insert ignore into journalissuearticles values(6.08-20.25%);, Fe 2 O 3 insert ignore into journalissuearticles values(2.09-6.39%); and K 2 O insert ignore into journalissuearticles values(1.43-2.24 %); were the dominant oxides. Traces elements were represented essentially by Ba insert ignore into journalissuearticles values(518-1202 mg kg -1 );, Zr insert ignore into journalissuearticles values(334-685 mg kg -1 ); and Sr insert ignore into journalissuearticles values(71-190 mg kg -1 );. The overall features are suitable to dry season sorghum production. The amount of smectites seemed to be an important factor affecting their water holding capacity on which dry season sorghum production depends. Improved cropping systems have to be developed to sustain productivity in vertisols with low smectites and where annual rainfall is lesser.
Keywords : Topomorphic vertisols, clay, smectites, dry season sorghum, North Cameroon

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