References
- Adegbenro R.O., Ojetade J.O., Muda S.A., Amusan A.A., Oguntade O.A., and Faturoti O.M. (2023): Characterization and suitability assessment of the soils of Iwo series for cocoa production in rainforest area Southwestern, Nigeria. Journal of Agricultural Science and Practice, 8(3): 45–52. https://doi.org/org/10.31248/JASP2023.411
- Afoakwa E.O. (2014): Cocoa Product ion and Processing Technology. (1st Ed.). Boca Raton, CRC Press. https://doi.org/org/10.1201/b16546
- Awwal Y.A., Maniyunda L.M. (2023): Toposequence effect on soil properties and suitability rating for selected crops in Northern Guinea Savanna, Nigeria. Journal of Agriculture and Environment 19(2): 215–235. https://doi.org/org/10.4314/jagrenv.v19i2.21
- Ayorinde K., Lawal R.M., Muibi K. (2015): Land Suitability Assessment for Cocoa Cultivation in Ife Central Local Government Area, Osun State. International Journal of Scientific Engineering and Research 3: 139–144. https://doi.org/org/10.4018/jagr.2012010107
- Bremner J.M., Mulvaney C.S. (1982): Nitrogen-Total. In A.L. Page, R.H. Miller, D.R. Keeney (Eds): Methods of Soil Analysis Part 2. Chemical and microbiological properties (pp. 595–624). Madison, American Societ y of Agronomy. https://doi.org/10.2134/agronmonogr9.2.2ed.c31
- Chapman J.D., Chapman H.M. (2001): The Forests of Taraba and Adamawa States, Nigeria: An ecological account and plant species checklist. Christchurch, University of Canterbury Press. https://doi.org/org/10.2307/4110842
- FAO (1976): A framework for land evaluation. Soils Bulletin 32. Rome, Food and Agriculture Organization of the United Nations.
- FAO (2006): Guidelines for Soil Description (4th ed.). Rome, Food and Agriculture Organization of the United Nations.
- GADM (2023): GADM database of Global Administrative Areas, version 4.1 [Data set]. GADM. https://gadm.org
- Google (2025): Google Earth Pro (version 7.3) [Computer software]. https://www.google.com/earth
- International Cocoa Organization (2023): Production of cocoa beans. Retrieved October 12, 2024. https://icco.org/wp-content/uploads/Production_QBCS-XLIX-No.-4.pdf
- Kehinde A.D., Ogundeji A.A. (2022): The simultaneous impact of access to credit and cooperative services on cocoa productivity in South-western Nigeria. Agriculture & Food Security 11: 11. https://doi.org/10.1186/s40066-021-00351-4
- Kongor J.E., Owusu M., Oduro-Yeboah, C. (2024): Cocoa production in the 2020s: challenges and solutions. CABI Agriculture and Bioscience 5: 102. https://doi.org/10.1186/s43170-024-00310-6
- Koulouri M., Giourga C. (2007): Land abandonment and slope gradient as key factors of soil erosion in Mediterranean terraced lands. Catena 69: 274–281. https://doi.org/org/10.1016/j.catena.2006.07.001
- Maniyunda L.M. (2012): Pedogenesis of a Lithosequence in the Northern Guinea Savanna of Kaduna State, Nigeria. Ph.D. Dissertation. Ahmadu Bello University Zaria, Nigeria. https://kubanni.abu.edu.ng/items/caee9deb-6616-4281-8289-0c51f5ba7e69
- McLean E.O. (1982): Soil pH and Lime Requirement. In: A.L. Page (Ed.): Methods of Soil Analysis Part 2 Chemical and Microbiological Properties (pp. 199–224). Madison, Soil Science Society of America Press. https://doi.org/10.2134/agronmonogr9.2.2ed.c12
- NASA POWER Data Access Viewer (2024): National Aeronautics and Space Administration Prediction of Worldwide Energy Resources (POWER) [Data set]. NASA. https://power.larc.nasa.gov
- Nelson D.W., Sommers L.E. (1996): Total carbon, organic carbon and organic matter. In D.L. Sparks, A.L. Page, P.A. Helmke, R.H. Loeppert, P.N. Soltanpour, M.A. Tabatabai, C.T. Johnston, M.E. Summer (Eds): Methods of Soil Analysis Part 3, Chemical Methods (pp. 960–1010). Madison, Soil Science Society of America Press. https://doi.org/org/10.2136/sssabookser5.3
- Ogunkunle A.O. (1993): Soil in land suitability evaluation: An example with oil palm in Nigeria. Soil Use and Management 9: 35–40. https://doi.org/org/10.1111/j.1475-2743.1993.tb00925.x
- Olasoji H.O., Ojetade J.O., Muda S. A., Amusan A.A. (2022): Characterisation, classification and suitability assessment of soils formed in granite and gneiss in humid area of southwestern Nigeria for cacao (Theobroma cacao) production. Tropical Agriculture 99: 11–26.
- Olsen S.R., Sommers L.E. (1982): Phosphorus. In A.L. Page, R.H. Miller, D.R. Keeney (Eds): Methods of soil analysis Part 2 (pp. 403–430). Wisconsin, America Society of Agronomy Press.
- OpenStreetMap contributors (2024): Planet dump [Data set]. OpenStreetMap. https://www.openstreetmap.org
- Osei-Gyabaah A.P., Antwi M., Addo S., Osei P. (2023): Land suitability analysis for cocoa ( Theobroma cacao) production in the Sunyani municipality, Bono region, Ghana. Smart Agricultural Technology 5: 100262. https://doi.org/org/10.1016/j.atech.2023.100262
- Osujieke D., Obasi S. (2024): Status and Pedogenetic Distribution of Selected Extractable Micronutrients in Mambilla Plateau-Montane Soils of Nigeria. Bulgarian Journal of Soil Science 9: 145–159.
- Otekunrin O.A. (2025): Mapping cocoa research (Theobroma cacao L.) in Africa: production, trade outlook, and scientometric insights. Discover Agriculture 3: 111. https://doi.org/10.1007/s44279-025-00298-1
- Oyebiyi O.O., Fagbohun U.O., Egbinola O.A., Ojetade J.O., Muda S.A., Adewumi O.A. (2024): Evaluation of soil properties variability along a toposequence in Wasinmi, Southwest Nigeria. Agricultura Tropica et Subtropica, 57: 90–99. https://doi.org/10.2478/ats-2024-0009
- Rabia A.H. (2012): A GIS based land suitability assessment for agricultural planning in Kilte Awulaelo district, Ethiopia. In: Proceedings of the Soil science for the benefit of mankind and environment: 4th International Congress of ECSSS, EUROSOIL 2012 (pp. 1–10). Bari, Italy.
- Rojas-Briceño N.B., García L., Cotrina-Sánchez A., Goñas M., López S.R., López S.J.O., Oliva-Cruz M. (2022): Land Suitability for Cocoa Cultivation in Peru: AHP and MaxEnt Modeling in a GIS Environment. Agronomy 12: 2930. https://doi.org/10.3390/agronomy12122930
- Sales M.A., Sales S.C., Badayos R.B., Sanchez P.B. (2024): Land Suitability Evaluation of Cocoa (Theobroma cacao L.) Production Areas in Davao City, Philippines. Mindanao Journal of Science and Technology 22: 1–19.
- Sumner, M.E., Miller, W.P. (1996): Cation Exchange Capacity and Exchange Coefficients. In: D.L. Sparks (Ed.), Methods of Soil Analysis: Part 3 – Chemical Methods (pp. 1201–1230). Madison, Soil Science Society of America.
- Taghizadeh-Mehrjardi R., Nabiollahi K., Rasoli L., Kerry R., Scholten T. (2020): Land Suitability Assessment and Agricultural Production Sustainability Using Machine Learning Models. Agronomy 10: 573. https://doi.org/10.3390/agronomy10040573
- Thomas G.W. (1982): Exchangeablecations. In A.L. Page, R.H. Buxton, D.R. Miller Keeney (Eds.): Methods of Soil Analysis, Part 2, Chemical and Microbiological Properties (pp. 159–164). Madison, Soil Science Society of America.
- Thomas G.W. (1996): Soil pH and soil acidity. In L.D. Sparks (Ed.): Methods of soil analysis, Part 3 – Chemical methods (pp. 475–490). Madison, Soil Science Society of America.
- Tijani M.N. (2023): Geology of Nigeria. In A. Faniran, L.K. Jeje, O. A. Fashae, A.O. Olusola (Eds.): Landscapes and Landforms of Nigeria (pp. 3–32). Springer. https://doi.org/10.1007/978-3-031-17972-3_1.
- Udoh B.T., Ogunkunle A.O. (2012): Land Suitability Evaluation for Maize (Zea mays) Cultivated in a Humid Tropical Area of South Eastern Nigeria. Nigerian Journal of Soil Science 22: 1–10.
- USDA (2017): Soil survey manual (C. Ditzler, K. Scheffe, H. C. Monger, Eds.; USDA Handbook No. 18). Government Printing Office. https://www.nrcs.usda.gov/resources/guides-and-instructions/soil-survey-manual
- Van Asselen S., Verburg P.H. (2012): A Land System representation for global assessments and land-use modeling. Global Change Biology 18: 3125–3148. https://doi.org/10.1111/j.1365-2486.2012.02759.x
- Webster R., Oliver M.A. (2007): Geostatistics for Environmental Scientists (2nd Ed.). Cornwall, John Wiley & Sons.
- Weil R.R., Brady N.C. (2017): The Nature and Properties of Soils (15th Ed.). New York, Pearson Education Publisher.
- Wells J.M., Crow S.E., Sierra C. A. et al. (2022): Edaphic controls of soil organic carbon in tropical agricultural landscapes. Scientific Reports 12: 21574. https://doi.org/10.1038/s41598-022-24655-y