Journal of Geosciences and Geomatics
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Journal of Geosciences and Geomatics. 2018, 6(3), 124-137
DOI: 10.12691/jgg-6-3-3
Open AccessLiterature Review

Nature and Genesis of Vertisols and North Cameroon Management Experience: A Review

P. Azinwi Tamfuh1, 2, , E. Temgoua1, V.L. Onana3, P. Wotchoko4, F.O. Tabi1 and D. Bitom1

1Department of Soil Science, Faculty of agronomy and agricultural Sciences, University of Dschang, P.O. Box 222 Dschang, Cameroon

2Department of Mining and Mineral Engineering, National Higher Polytechnic Institute, University of Bamenda, P.O. Box 39 Bambili, Cameroon

3Department of Earth Science, Faculty of Science, University of Yaoundé I, P.O. Box 812 Yaoundé, Cameroon

4Department of Geology, Higher Teacher Training College, University of Bamenda, P.O. Box 39 Bambili, Cameroon

Pub. Date: October 24, 2018

Cite this paper:
P. Azinwi Tamfuh, E. Temgoua, V.L. Onana, P. Wotchoko, F.O. Tabi and D. Bitom. Nature and Genesis of Vertisols and North Cameroon Management Experience: A Review. Journal of Geosciences and Geomatics. 2018; 6(3):124-137. doi: 10.12691/jgg-6-3-3

Abstract

Vertisols are tropical soils that occur world-wide (335 million ha) with high agricultural and other engineering potentials. However, they are underutilized as most of their physical characteristics make management techniques difficult and highly localized. This paper aims to highlight the characteristics, genesis and management strategies of Vertisols for sustainable use. Two main types of Vertisols can be distinguished: topomorphic Vertisols with A(B)gC or difficult A(B)Cg profile and lithomorphic with A(B)C profile type. Vertisols generally show a dark colour, very high compacity, surficial desiccation cracks when dry, surface ponding when moist and large sub-surface slickensides. They contain at least 30% clay fraction, while smectite, cation exchange capacity and base saturation are very high. Lithomorphic Vertisols are developed on various parent rocks and topographic positions where weathering generates base-rich environments that promote smectite synthesis. The formation of topomorphic Vertisols is favoured by low landscape positions suitable for accumulation of basic cations. The latter cover very extensive surface areas of the globe mainly in tropical, semi-arid to (sub) humid and Mediterranean climates showing contrasting wet and dry seasons, while the former have limited geographical extensions and occur mainly in specific islands and volcanic regions. Swelling and shrinking upon wetting and drying is a major characteristic of Vertisols. Most of their properties and uses are dependent on shrink-swell behaviour. Micromorphologically, plasmic separations occur in all Vertisols especially in the middle part of the profile where shrink/swell is most pronounced. Most Vertisols fall under the A-7-5 and A-7-6 classes typical of inorganic clays of medium to very high plasticity designated as bad clays according to AASHTO. Vertisols present numerous interesting uses in the chemical industry, pharmaceutics, agronomy and environmental protection. Nevertheless, man-made structures on Vertisols are not advisable since large investments are needed to maintain and repair damaged infrastructure. In North Cameroon, vertisols cover about 1 200 000 hectares and agricultural management strategies are mainly tilted at moisture control, but also at fertility restoration.

Keywords:
vertisols smectite expansive clays fabric genesis management North Cameroon

Creative CommonsThis work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]  Dudal, R, Sols argileux foncés des régions tropicales et sub-tropicales, F.A.O., Rome, 1965, 172p.
 
[2]  FAO-UNESCO-ISRIC, Soil map of the world. Revised legend, World Soil Resources Report, FAO, Rome, 1990.
 
[3]  Grunwald, S, Vertisols. University of Florida, Florida, 2003. Available: http://soils. Ifas.ufl.edu. Accessed on 9/25/2018.
 
[4]  Kovda, I. V., Morghun, E.G. and Ryskov Y.G, “Structural-functional analysis of gilgai microcomplex soils: morphological features and dynamics of humidity”, Pochvovedeni, 11, 1326-1339, 1995.
 
[5]  Kovda, I., Goryachkin, S., Lebedeva, M., Chizhikova, N., Kulikov, A. and Badmaev, N, “Vertic soils and Vertisols in cryogenic environments of southern Siberia, Russia”. Geoderma, 288, 184-195, 2017.
 
[6]  Podwojewski, P, “The occurrence and interpretation of carbonate and sulphate minerals in a sequence of Vertisols in New Caledonia”. Geoderma, 65, 223-248, 1995.
 
[7]  Duchaufour, P, Handbook of pedology: sol-vegetation- environment. Masson, Paris, 1997, 291p.
 
[8]  Podwojewski, P, Gibbsic Vertisols of the New Caledonia in their pedologcal environment, Thèse Doct., Université de Louis-Pasteur, Strasbourg, 1992, 238p.
 
[9]  Nguetnkam, J. P., Kamga, R., Villiéras Ekodeck, G. E. and Yvon, J, “Weathering response of granite in tropical zones. Example of two sequences studied in Cameroon (Central Africa)”, Etude et Gestion des Sols, 14 (1), 13-41, 2007.
 
[10]  Pal, D.K., Wani, SP. and Sahrawat K,L, “Vertisols of tropical Indian Enviroments: pedology and Edaphology”, Geoderma, 189-190, 28-49, 2012.
 
[11]  Eswaran, H. and Cook, T, “Classification and management related properties of Vertisols,” In proceedings of the of a Conference held at ILCA on the management of Vertisols in Sub-Saharan Africa,. Jutsi, S. C., Haque, I.. McIntire J. and shares J. (Eds)., Adis Ababa, Ethiopia, 64-84.
 
[12]  Raunet, M, “Quelques clés morpho-pédologiques pour le Nord Cameroun á l’usage des agronomes”, CIRAD, Montpellier, 2003, 24p.
 
[13]  Nguetnkam, J.P, Les argiles des Vertisols et des sols fersiallitiques de l’Extrême nord Cameroun: Genèse, propriétés cristallochimiques et texturales, typologie et applications à la décoloration des huiles végétales, Thèse Doct. Etat. Univ. Ydé I, Yaounde, 2004, 218 p.
 
[14]  F.A.O, Guidelines for soil description, a framework for international classification, correlation and communication. FAO-ISRIC-IUSS, 4th edition, Rome, 2006, 128p.
 
[15]  Aydinalp, C, “Some important properties and classification of Vertisols under Mediterranean climate”, African Journal of Agricultural Research, 6 449-452, 2010.
 
[16]  Bocquier, G, Génèse et évolution de deux toposéquences des sols tropicaux du Tchad. Interprétation biogéochimique, ORSTOM, Paris, 1973, 350p.
 
[17]  Djoufac Woumfo, E., Elimbi, N., Pancder, G., Nyada, R. N. and Njopwouo, D, “Caractérisations physico-chimiques et minéralogiques des Vertisols de Garoua (Nord Cameroun)”. J. Ann. Chim. Sci. Mat, 1, 75-90, 2006.
 
[18]  Kamgang Kabeyene, B. V., Likibi B., Ndome Effoudou, P.E. and Ekodeck, G. E, “Mineralogy and geochemistry of vertisols at Ferngo, Lake Chad basin: their potential as raw materials for fired bricks”, Ann. Fac. Scie. Univ. Yaoundé I., série Science de la Nature et de la Vie, 38 (1), 30-44, 2011.
 
[19]  Temga, J.P., Nguetnkam, J.P., Balo, M.A., Basga, S.D. and Bitom, D, “Morphological, physico-chemical, mineralogical and geochemical properties of vertisols used in bricks production in the Logone Valley (Cameroon, Central Africa)”, International Reseearch Journal of Geology and Mining, 5(1), 20-30, 2015.
 
[20]  Nguetnkam, J. P., Kamga, R., Villiéras, F., Ekodeck, G. E. and Yvon, J, “Assessing the bleaching capacity of some Cameroonian clays on vegetable oil”, Applied Clay Science, 39, (3-4), 113-121. 2008.
 
[21]  USDA, Soil classification. A comparative system (7th approximation, USDA, Washington DC, 1960, 265p.
 
[22]  Butt, C.R.M, “Physical weathering and dispersion,” In Regolith exploration geochemistry in tropical and sub-tropical terrains, Govette C.J.S (Ed.), Handbook of exploration geochemistry, Elsevier 4, London, 1992, 96-113.
 
[23]  Özsoy, G. and Aksoy, E, “Characterization, classification and agricultural usage of Vertisols developed on neogen aged calcareous marl parent materials”, .Journal of Biological and Environmental Sciences, 1, 5-10, 2007.
 
[24]  McGarry, D, “The structure and grain size distribution of Vertisols,” In Vertisols and technologies for their management, Ahmad, N. and Mermut, A, (Eds.), Developments on Soil Science 24, Elsevier, Amsterdam,. 231-259, 1996.
 
[25]  Eswaran, H., Beinroth, F.H., Reich, P.F. and Quandt, L.A, “Guy D. Smith memorial slide collection,” in Vertisols: their properties, classification, distribution and management, USDA Natural Resources Conservation Service, Washington, DC, 1999.
 
[26]  Mohr, E.C.J., Van Baren, F.A. and Van Schuylenborgh, J, “Tropical soils”, Mouton, The ratio law applied under field conditions”. Plant and Soil, 19, 33-48. 1972.
 
[27]  Debele, B, “The Vertisols of Ethiopia: their properties, classification and management,” In Proceedings of the Fifth Meeting of the Eastern African soil Correlation and Land Evaluation Sub-Committee, F.A.O., (Ed.), World soil resources report, 56, Rome,. 31-54, 1985.
 
[28]  Azinwi Tamfuh, P., Djoufac Woumfo E., Bitom, D., Njopwouo, D, “Petrological, physico-chemical and mechanical study of the topomorphic Vertisol of the sudano-sahelian region of north Cameroon”. The Bentham Open Geology Journal, 5, 33-55, 2011.
 
[29]  Azinwi Tamfuh, P, “Petrological, physico-chemical and mechanical study of the Benue watershed Vertisols (North Cameroon): spatial analysis and agricultural potential evaluation”. PhD thesis, University of Yaoundé I, Yaoundé, Cameroon, 2012, 183p.
 
[30]  Corbeels, M, “Adoption potential for conservation agriculture in Africa: a newly developed assessment approach (QAToCA) applied in Kenya and Tanzania. Land Degradation and Development, 26, 133-141, 2015.
 
[31]  Likibi, B, Altérologie des formations superficielles de la région de Maroua et potentialités de leur valorisation. Thèse Doct., Université de Yaoundé 1, Yaoundé, Cameroun, 2010, 251p.
 
[32]  Ahmad N, “Occurrence and distribution of Vertisols” In Vertisols and technologies for their management, Ahmad N. and Mermut A., Eds, Developments in Soil Science, 24, Elsevier, Amsterdam, 1996, 1-41.
 
[33]  Ambassa-Kiki, R., Aboubakar, Y. and Boulama, T, Zero-tillage for rice production on Cameroonian Vertisols. Soil and Tillage Research , 39.75-77, 1996.
 
[34]  Nordt, L. C. and Driese, S. G, “Hydropedological model of vertisol formation along the Gulf Coast Prairie land resource area of Texas”, Hydrology and Earth Systems Sciences, 13, 2039-2053, 2009.
 
[35]  Fisseha, I, Micro and macronutrient distributions in Ethiopian Vertisol landscapes, Hohenheimer Bodenkundliche, 2, Universität Hohenheim, Stuttgart, 1992, 202p.
 
[36]  Yerima, B. P. K., Van Ranst, E., Sertsu, S. and Verdoodt, A, “Pedogenic impacts on the distribution of total and available Fe, Mn, Cu, Zn, Cd, Pb and Co contents of Vertisols and vertic inceptisols of the Bale Mountain area of Ethiopia”. African Journal of Agricultural Research, 8(44), 5429-5439, 2013.
 
[37]  Nalovic, Lj, “Etudes des éléments traces et leurs distributions dans quelques types de sols malgaches”, Cah. ORSTOM, sér. Pédol, 17, 133-181, 1969.
 
[38]  Buhmann, C. and Schloeman, J. L, “A mineralogical characterization of Vertisols from the northern regions of the Republic of South Africa”, Geoderma, 66, 239-257, 1995.
 
[39]  Blokhuis, W. A, “Morphology and genesis of Vertisols,” In 12th International Congress of Soil Science of 8--16 February 1982 on Vertisols and rice soils of the tropics, Indian Society of Soil Science, New Delhi, 1982, 23-45.
 
[40]  Newman, A. L, Vertisols in Texas: some comments, USDA-SCS, Texas, 1988, 206p.
 
[41]  Dudal, R. and Eswaran, H, “Distribution, properties and classification of Vertisols,” In Vertisols: their distribution, properties, classification, and management, Wilding L. P. and Puentes R.(Eds.), Technical Monograph No. 18, Texas AandM University Printing Center, College Station, Texas, 1988, 1-22.
 
[42]  Bourgeon, G, “Esquisse sur les grandes zones des sols du Sud de l’Inde”. Cah. ORSTOM, sér. Pédol, 24 (4), 303-328, 1988.
 
[43]  Gavaud, M., Muller, J. P. and Fromaget, M, “Les étapes de l’évolution des sols dans les alluvions de la Bénoué (Nord Cameroun). Cah. ORSTOM, sér. Pédol, 14, 321-335, 1976.
 
[44]  Azinwi Tamfuh, P, Djoufac Woumfo, E., Tabi, FO., Angue-Abossolo, M. and Bitom, D, “Geostatistical modeling and agricultural perspectives of Vertisol properties in the Benue floodplain of North Cameroon” Global Advanced Research Journal of Agricultural Science, 7(7), 197-216, 2018a.
 
[45]  Azinwi Tamfuh P, Djoufac Woumfo E, Temgoua E, Boukong A. and Bitom D, “Moisture, moisture-related properties and agricultural management strategies of the Benue floodplain Vertisols in North Cameroon”, African Journal of Agricultural Research 13 (33), 1730-1746, 2018b.
 
[46]  Page, S.L.J, “Effects of the physical properties of two tropical Cotton soils on their permanent wilting point and relative humidity, in relation to survival and distribution of Meloidogyne acronea”, Revue Nématologique, 7 (3): 227-232, 1984.
 
[47]  Coulombe, C.E., Dixon J.B. and Wilding, L.P, “.Mineralogy and physical chemistry of Vertisols.” In Vertisols and technology for their management, Ahmad, M. and Mermut, A, (Eds.), Texas A and M University, Texas, Elsevier Science Publishers, 2006, 115-200.
 
[48]  Blokhuis, W. A., Slager S. and van Schagon, R. H, “Plasmic fabrics of two Sudan Vertisols”, Geoderma, 4, 127-137, 1970.
 
[49]  Bellinfante, N., Paneque, G., Olmedo, J. and Banos, C, “Micromorphological study of Vertisols in Southern Spain,” In Soil microscopy, Rutherford, G. K. (ed.), Queen’s University, Ontario, Canada, 1974, 296-305.
 
[50]  Blokhuis, W.A., Kooistra, M.J., and Wilding, L.P, “Micromorphology of cracking clayey soils (Vertisols),” in Soil Micromorphology: A Basic and Applied Science, Douglas, L.A., (ed.),: New York, Elsevier Pub. Co., Developments in Soil Science, 19, 1990, 23-148.
 
[51]  Brewer, R, Fabric and mineral analysis on soils,. Willey and Sons , London, 1964.
 
[52]  Mermut, A.R., Seghal, J. L. and Stoops, G, “Micromorphology of swell-shrink soils”. In Transactions of International Workshop on Swell-Shrink soils: classification, management and use potential of swell-shrink soils held in Nagpur (India) of 24-28 Oct 1988, National Bureau of Soil Survey and Land Use Planning (Eds.), Nagpur, 1988, 127-144.
 
[53]  Yaalon, D.H. and Kalmar, D, “Dynamics of cracking and swelling clay soils: displacement of skeletal grains, optimum depth of slickensides and rate of intrapedogenic turbation, Earth Surf Proc, 3, 31-42, 1978.
 
[54]  Yerima, B.P.K.., Calhoun, F.G., Senkayi, A.L. and Dixon, J.B, Occurrence of interstratified kaolinite-smectite in El Salvador “Vertisols”, Soil Science Society of America Journal, 49, 462-466, 1985.
 
[55]  Yerima, B.P.K., Wilding, L.P. and Hallmark CT, “Statistical relationships among selected properties of Northern Cameroon vertisols and associated alfisols” Soil Science Society of American Journal, 53, 1758-1763, 1989.
 
[56]  Bucher, F. and Sailie, E.L, “Swelling behaviour of tropical black clays, “ in Proceedings of the 8th African Regional Conference on Soil mechanics and Foundation Engineering, Harare,. 81-86, 1984.
 
[57]  Fassil Kebede, “Silicon status and its relationship with major physico-chemical properties of vertisols in of Northern Highlands of Ethiopia,” College of Dryland Agriculture and Natural Ressources Management Journal, 1, 74-81, 2009.
 
[58]  Ruxton, B. P, “Measure of the degree of chemical weathering of rocks, Journal of Geology, 76, 518-527, 1968.
 
[59]  Price, J.R. and Velbel, M. A, Chemical weathering indices applied to weathering profiles developed on heterogeneous felsic metamorphic parent rocks. Chemical Geology, 202, 397-441, 2003.
 
[60]  Azinwi Tamfuh, P., Djoufac Woumfo, E., Tabi, F.O., Boukong, A., Mvondo Ze, A.D., Bitom, D. and Kamgang Kabeyene, VB, “Morphology, physicochemical characteristics, nutritional status and fertility capability classification of the Benue floodplain Vertisols in North Cameroon”, Journal of Geography, Environment and Earth Science International 6(1), 1-15, 2016.
 
[61]  Chan, K.Y., The Late Hodgson, A.S., Bowman, A.M, “Degradation of Australian vertisols after conversion from native grassland to continuous cropping in a semi-arid sub-tropical environment”, Tropical Grasslands, 29, 210-217, 1995.
 
[62]  Murthy, R.S., Bhattacharjee, J.C., Landey, R. J. and Pofalli, R. M, “Distribution, characteristics and classification of Vertisols,” In the 12th International Congress of Soil Science on Vertisols and rice soils of the tropics, New Delhi, 1982, 3-22.
 
[63]  Gardner, E.A., Coughlan, K.J. and Silburn, D.M, “Soil water measurement and on Vertisols in Queensland (Australia),” Proceeding of a Conference held at ILCA on the management of Vertisols in Sub-Saharan Africa, S.C. Jutzi, I. Haque, J. McIntire and Jes Shares (EdS), ILCA, Addis Ababa, Ethiopia, 1988, 131-164.
 
[64]  Yerima, B.P.K., Van Ranst, E. and Verdoodt, A, “Use of correlation relationships to enhance understanding of pedogenic processes and use potential of vertisols and vertic inceptisols of the Bale mountain area of Ethiopia, Tropicultura 27(4), 223-232, 2009.
 
[65]  Gidigasu, S. S. R. and Gawu, S. K. Y, “The Mode of formation, nature and geotechnical characteristics of black cotton soils - A Review”, Standard Scientific Research and Essays, 1 (14), 377-390, 2013.
 
[66]  Pal, D.K., Wani, S.P. and Sahrawat, K.L, “Vertisols of tropical Indian environments: Pedology and edaphology”, Geoderma, 189-190, 28-49, 2012.
 
[67]  Soil Survey Staff, Keys to soil taxonomy, United States Dept. of Agriculture, Natural Resource Conservation Service, Washington, DC 2014.
 
[68]  Soil Survey Staff, Soil taxonomy: a basic system of soil classification for making and interpreting soil surveys, Agriculture handbook no. 436, Soil Conservation Service, US Dept. of Agriculture, Washington, DC, 1975.
 
[69]  USAID/BRRI (United States Agency for International Development/Building and Road Research Institute), Laterite and Lateritic Soils and other Problem Soils of Africa, An Engineering Study Report, AID/CSD – 2164, 1971, 290p.
 
[70]  Thompson, C. H. and Beckman, G. C, “Gilgai on Australian black earths and some of its effects on plants”. Trop. Agriculture, 59, 149-156, 1982.
 
[71]  Seini-Boukar, L., Floret, C. and Pontanier, R, Degradation of savannah soils and reduction of water available for the vegetation: the case of northern Cameroon Vertisols. Cameroon Journal of Soil Science, 72 (4), 459-488, 1992.
 
[72]  Stace, H.C.T., Hubble, G.D., Brewer, R., Northcote, K.H., Sleeman, J.R., et al, A handbook of Australian soils, Relim Tech. Publ., S. Australia, 1968.
 
[73]  Jewitt, T.N., Law, R.D. and Virgo, K.J, Outlook on Agriculture 10, 33, 1979.
 
[74]  Swindale, L.D, “Developing, Testing and transferring improved Vertisol technology, the Indian experience,” In Proceedings of a conference held at ILCA on the Management of Vertisols in sub-Saharan Africa on 31st August-4th September 1987, .Jutz, Haque, S.C., ,McIntire, J. and Stares, J.E.S, (Eds), Addis Ababa, 1987, 13-43.
 
[75]  Virgo, K.J. and Munro, R.N, Soil and erosion features of the Central Plateau Region of Tigrai, Ethiopia. Geoderma, 20(2), 131-257, 1978.
 
[76]  Patil, N. G., Pal, D. K., Mandal, C. and Mandal, D. K, Soil water retention characteristics of Vertisols and pedotransfer functions based on nearest neighbour and neural networks approaches to estimate available water capacity. Journal of irrigation and drainage engineering, 138, 177-184, 2012.
 
[77]  Mamo, T., Haque, I. and Camara, C.S, “Phosphorus status of some Ethiopian Highland Vertisols”, in proceedings of a Conference held at ILCA on the Management of Vertisols in Sub-Saharan Africa, S. C. Jutsi, I. Haque, J. McIntire and J. shares (Eds.), Addis Ababa, Ethiopia, 1988, 232-249.
 
[78]  Shainberg, I., Alperrovitch, N. and Keren, R, “Effect of magnesium on hydraulic conductivity of Na-smectite- sand mixtures”, Clays and Clay Minerals, 36, 432-438, 1988.
 
[79]  Fredlund, D. G, “Geotechnical problems associated with swelling clays”, In Vertisols and technologies for their management, Ahmad, N. and Mermut, A. (eds.), Developments in Soil Science, 24, Elsevier, Amsterdam, 1996, 499-521.
 
[80]  Skempton, A.W, “The colloidal activity of clays”, In Proceedings of a 3rd International Conference on Soil Mechanics and Foundation Engineering, 1, 57-61, 1953.
 
[81]  ASTM, “Classification of soils for engineering purpose, In Annual book of American Society for Testing Minerals Standards, American Society for Testing Materials (Ed.), 4 (8), 1985, 395-408.
 
[82]  Nyakach, S., Owido, F.O.S. and Oyando, J. Effect of firing time and temperature on selected physical properties of black cotton soils. Journal of Agricultural Science and Engineering, 3 (1), 1-12, 2017.
 
[83]  Kamga, R., Nguetnkam, J.P. and Villeras, F, “Caractérisation des argiles du Nord Cameroun en vue de leur utilisation dans la décoloration des huiles végétales”, In Proceedings of the First Conference on the Valorisation of Clay Minerals in Cameroon, Nkoumbou, C. and Njopwouo, D, (Eds.), Univ. of Yaoundé I, Yaoundé , 2001, 247-257.
 
[84]  Temga, J.P., Balo Madi, A., Basga Djagba, S., Zo’o Zame, P., Bitom, D.L, “Lime- and – sand stabilisation of clayey materials from the Logone Valley (Lake Chad basin) for their utilization as building materials”, Journal of Building Engineering, 19, 472-479, 2018.
 
[85]  Hubble, G. D., Isbell, R. F. and Northcote, K. H, “Features of Australian soils, In Soils: an Australian viewpoint, Division of soils, Csiro Publishers, Melbourne, 1983, 17-47.
 
[86]  McGarity J.W., Hoult E. H. and So H. B. “The properties and utilization of cracking clay soils”, in Reviews in Rural Science, 5, University of New England, Armidale, 1984, 57-68.
 
[87]  Folorunso, O.A., Ohu, O.J. and Adeniji, F.A, “The role of soil spatial variability investigation in the management of the Chad basin vertisols on N. E. Nigeria”, Soil Technology, 1(2), 149-156, 1986.
 
[88]  Folorunso, O.A., Njoku, E.A. and Kwakye, P. K, “The role of soil spatial variability investigations in the management of the Chad basin vertisols of North East Nigeria”, In Proceedings of a Conference held at ILCA on the Management of Vertisols in Sub-Saharan Africa, Eds Jutsi, S. C., Haque, I., McIntire, J., shares J, ILCA, Addis Ababa, Ethiopia, 1988, 125-126.
 
[89]  Mainam, J., Zinck, A. and Van Ranst, E, “Variation in the soil properties and crop characteristics due to soil erosion at plot scale in the semi-arid zone of Cameroon”, In Savanes africaines : des espaces en mutation, des acteurs face à de nouveaux défis, Jamin, J.Y., Seiny Boukar, L., Floret, C., (Eds.), CIRAD, Montpellier, 18-22, 2003.
 
[90]  Wilding, L.P. and Tessier, D, Genesis of Vertisols: shrink-swell phenomena, their distribution, properties, classification and management, Texas A and M University Press, College Station, 1988, 193p.
 
[91]  Wilding, L.P. and Coulombe, C,E, “Expansive soils: distribution, morphology and genesis”, in Proceedings NATO-ARW on clay swelling and expansive soils, .Baveya, P., McBride, M.B Kluwer, Eds, Academic Press, Dordrecht, 1996.
 
[92]  Buol, S.W., Hole, F.D., McCracken, R.J. and Southard, R.J, Soil genesis and classification, Lowa St. University Press, 1997.
 
[93]  Pal, D.K, Cracking clay soils (vertisols): pedology, mineralogy and taxonomy. In A treatise of Indian and Tropical soils (Chapter 2), Springer International Publishing AG, 9-42, 2017.
 
[94]  Brady, N. C. and Weil, R.R, The nature and properties of soils. 12th ed, Prentice-Hall, London, 1999.
 
[95]  Podwojewski, P, “Les Vertisols de la Nouvelles Calédonie”. Cah. ORSTOM, Sér. pédol.14 (4), 279-301, 1988.
 
[96]  Goe, M, “Effect of tillage frequency of clay soils on the draught of the Ethiopian ard (MARESHA)”, in Proceedings of a Conference held at ILCA on the Management of Vertisols in Sub-Saharan Africa, Jutsi, S. C., Haque, I., McIntire J. and shares, J, Eds, ILCA, Adis Ababa, 1988, 380-381.
 
[97]  Latham, M. and Ahn, P.M, “Networking on Vertisol management concepts, problems and developments”, In proceedings of a Conference held at ILCA on the Management of Vertisols in Sub-Saharan Africa,. Jutsi, S.C., Haque, I., McIntire, J. and shares, J, Eds., Adis Ababa, Ethiopia, 1988, 399-411.
 
[98]  Mahmoud, M. A, “Rain-fed agriculture and farming systems on Vertisols”, in proceedings of a Conference held at ILCA on the Management of Vertisols in Sub-Saharan Africa, Jutsi, S. C., Haque, I., McIntire J. and shares, J, Eds, ILCA, Adis Ababa, Addis Ababa, 1988, 335-336.
 
[99]  Krohn, J.P. and Slossen, J.E, “Assessment of expansive soils in the United states”, In Proceedings of the 4th International Conference on expansive soils, Colorado, 1980, 596-608.
 
[100]  Holtz, R. D. and Kovacs, W. D, Introduction to Geotechnical Engineering. Ecole Polytechnique de Montréal, Montréal, 1981, 808p.
 
[101]  Jones, D.E and Holtz, W.G, “Expansive soils, the hidden disaster”, American Society of Civil Engineering Journal, 31, 87-89, 1973.
 
[102]  Ségalen, P, “Les sols et la géomorphologie du Cameroun”. Cah. ORSTOM, sér. Pédol., 5, 137-187, 1967.
 
[103]  Pias, J, “Contribution à l’étude des formations sédimentaires tertiaires et quartenaires de la cuvette Tchadienne et des sols qui en dérivent”, Cah. ORSTOM, Sér. Pédol., 16(3-4), 366-377, 1969.
 
[104]  Gavaud, M., Rieffel J.M. et Muller, J.P, Les sols de la vallée de la Bénoué, de Lagdo jusqu’au confluent du Faro. ORSTOM, Bondy, 1975. 690p.
 
[105]  Brabant, P. et Gavaud, M, Les sols et les ressources en terres du Nord Cameroun (Province du Nord et de l’Extrệme Nord). ORSTOM-MESRES-IRA, Paris, 1985, 285p.
 
[106]  Obale-Ebanga, F., Sevink, J., de Groot W. and Nolte, C, “Myths of slash and burn on physical degradation of savannah soils: impacts on Vertisols in North Cameroon. Soil Use and Management, 19, 83-86, 2002.
 
[107]  Diaz, N., Dietrich, F., Cailleau, G., Sebag, D., Ngounou Ngatcha, B. and Verrecchia, E.P, “Can mima-like mounds be Vertisol relics (Far North Region of Cameroon, Chad Basin)?” GEMOR, 2016.
 
[108]  Ekodeck, G.E. et Eno Belinga, S.M, () Les dépôts superficiels gonflants du Nord Cameroun: causes et conséquences de leur comportement géotechnique, Les Annales de la Faculté des Sciences, 21-22, 39-46, 1977.
 
[109]  Yerima, B.P.K., Soil genesis, phosphorus and micronutrients of selected Vertisols and associated Alfisols of Northern Cameroon. Ph.D thesis. Texas A and M University, College Station, 1986, 342p.
 
[110]  Gavaud, M., Rieffel, J.M. et Muller J.P, Les sols de la vallée de la Bénoué, de Lagdo jusqu’au confluent du Faro, ORSTOM, Bondy, 1975, 690p.
 
[111]  Brabant, J, “Selection of sites for Vertisol network: distinction between types of Vertisols”, IBSRAM Proceedings, 6, IBSRAM, Paris, 1987, 65-70.
 
[112]  Seignobos, C, “Harde et karral du Nord Cameroun, leur perception par les populations agropastorales du Diamaré”, in Les terres harde : caractérisation et réhabilitation dans le bassin du Lac Tchad, Cahier Science, CIRAD-Foret, Paris, 1993, 9-28.
 
[113]  Brabant, P. et Gavaud, M, Les sols et les ressources en terres du Nord Cameroun (Province du Nord et de l’Extrême Nord), ORSTOM-MESRES-IRA, Paris, 1985, 285p.
 
[114]  Mathieu, B., Duboisset, A., Gautier, D., Papy, F. and Dore, T, “Different levels to understand the spatial organization of muskwari’s cropping system”, In Actes du colloque international sur l’Organisation spatiale et gestion des ressources et des territoires ruraux, of 25 - 27 february 2003, Dugué, P., Jouve, Ph., Eds., .Montpellier, 2002.
 
[115]  Wafo Tabopda, G., Fotsing, J.-M. and Huaman, D, “Evolution du couvert végétal dans la réserve forestière de Laf-Madjam(Extrême Nord du Cameroun) de 1976 à 2003”, in Anais XII Simpósio Brasileiro de Sensoriamento Remoto, Goiânia, Brasil, 16-21 abril 2005, INPE, 2005, 3379- 3386.
 
[116]  Wafo Tabopda, G. and Fotsing J.-M, Les aires protégées de l’Extrême-Nord Cameroun entre politiques de conservation et pratiques locales, Sciences de l’Homme et Société, Thèse Doc, Université d’Orléans, 2008.