MW02. Malawi: 2. Soil and terrain suitability

Maps: Malawi 2. Soil and terrain suitability

Territorial scope: country
Themes: 2, 3, 4

Soil suitability dataset description
This map set illustrates the spatial distribution of soil suitability for 11 important crops in Malawi: beans, cassava, cotton, groundnut, maize, millet, rice, sorghum, soybean, sweet potato, and tobacco.

The soil properties used for suitability assessment include soil depth, texture, drainage, flooding, salinity, cation exchange capacity (CEC), and acidity (pH). Among these, salinity, CEC, and pH are key fertility indicators.
Soil suitability is assessed and mapped for each of these properties using the empirical criteria and thresholds established by Sys et al. (1993)*, resulting in ‘Soil Factor Suitability’ maps. The overall soil suitability score was determined by the lowest rating among the individual soil property scores.

This map set for Malawi is based on the national soil map of Malawi, developed at a scale of 1:250,000 and its associated soil property database (Venema, 1990)**. For methodological details and further information, including interpretations of the various maps, is referred to Publication 115b (2018).

Soil suitability for beans

MW02.01. Suitability score for cation exchange capacity (CEC)
MW02.02. Suitability score for soil depth
MW02.03. Suitability score for soil drainage
MW02.04. Suitability score for flooding
MW02.05. Suitability score for soil acidity (pH)
MW02.06. Suitability score for soil salinity
MW02.07. Suitability score for soil texture
MW02.08. Combined soil suitability score

Soil suitability for cassava

MW02.09. Suitability score for cation exchange capacity (CEC)
MW02.10. Suitability score for soil depth
MW02.11. Suitability score for soil drainage
MW02.12. Suitability score for flooding
MW02.13. Suitability score for soil acidity (pH)
MW02.14. Suitability score for soil salinity
MW02.15. Suitability score for soil texture
MW02.16. Combined soil suitability score

Soil suitability for cotton

MW02.17. Suitability score for cation exchange capacity (CEC)
MW02.18. Suitability score for soil depth
MW02.19. Suitability score for soil drainage
MW02.20. Suitability score for flooding
MW02.21. Suitability score for soil acidity (pH)
MW02.22. Suitability score for soil salinity
MW02.23. Suitability score for soil texture
MW02.24. Combined soil suitability score

Soil suitability for groundnut

MW02.25. Suitability score for cation exchange capacity (CEC)
MW02.26. Suitability score for soil depth
MW02.27. Suitability score for soil drainage
MW02.28. Suitability score for flooding
MW02.29. Suitability score for soil acidity (pH)
MW02.30. Suitability score for soil salinity
MW02.31. Suitability score for soil texture
MW02.32. Combined soil suitability score

Soil suitability for maize

MW02.33. Suitability score for cation exchange capacity (CEC)
MW02.34. Suitability score for soil depth
MW02.35. Suitability score for soil drainage
MW02.36. Suitability score for flooding
MW02.37. Suitability score for soil acidity (pH)
MW02.38. Suitability score for soil salinity
MW02.39. Suitability score for soil texture
MW02.40. Combined soil suitability score

Soil suitability for millet

MW02.41. Suitability score for cation exchange capacity (CEC)
MW02.42. Suitability score for soil depth
MW02.43. Suitability score for soil drainage
MW02.44. Suitability score for flooding
MW02.45. Suitability score for soil acidity (pH)
MW02.46. Suitability score for soil salinity
MW02.47. Suitability score for soil texture
MW02.48. Combined soil suitability score

Soil suitability for rice

MW02.49. Suitability score for cation exchange capacity (CEC)
MW02.50. Suitability score for soil depth
MW02.51. Suitability score for soil drainage
MW02.52. Suitability score for flooding
MW02.53. Suitability score for soil acidity (pH)
MW02.54. Suitability score for soil salinity
MW02.55. Suitability score for soil texture
MW02.56. Combined soil suitability score

Soil suitability for sorghum

MW02.57. Suitability score for cation exchange capacity (CEC)
MW02.58. Suitability score for soil depth
MW02.59. Suitability score for soil drainage
MW02.60. Suitability score for flooding
MW02.61. Suitability score for soil acidity (pH)
MW02.62. Suitability score for soil salinity
MW02.63. Suitability score for soil texture
MW02.64. Combined soil suitability score

Soil suitability for soybean

MW02.65. Suitability score for cation exchange capacity (CEC)
MW02.66. Suitability score for soil depth
MW02.67. Suitability score for soil drainage
MW02.68. Suitability score for flooding
MW02.69. Suitability score for soil acidity (pH)
MW02.70. Suitability score for soil salinity
MW02.71. Suitability score for soil texture
MW02.72. Combined soil suitability score

Soil suitability for sweet potato

MW02.73. Suitability score for cation exchange capacity (CEC)
MW02.74. Suitability score for soil depth
MW02.75. Suitability score for soil drainage
MW02.76. Suitability score for flooding
MW02.77. Suitability score for soil acidity (pH)
MW02.78. Suitability score for soil salinity
MW02.79. Suitability score for soil texture
MW02.80. Combined soil suitability score

Soil suitability for tobacco

MW02.81. Suitability score for cation exchange capacity (CEC)
MW02.82. Suitability score for soil depth
MW02.83. Suitability score for soil drainage
MW02.84. Suitability score for flooding
MW02.85. Suitability score for soil acidity (pH)
MW02.86. Suitability score for soil salinity
MW02.87. Suitability score for soil texture
MW02.88. Combined soil suitability score

* Reference 1: Sys, C., Van Ranst, E., Debaveye, J. and Beernaert,F. 1993. Land evaluation. Part III. Crop Requirements. Agricultural Publications No. 7, General Administration for Development Cooperation, Brussels, Belgium,199 pp.
**Reference 2: Venema, J. 1990. Methods of description, classification and mapping of the physiography and soils of Malawi. Malawi Government, Ministry of Agriculture, Land Husbandry Branch/ United Nations Development Programme and Food and Agriculture Organisation of the United Nations. Lilongwe: UNDP/FAO.

Terrain suitability maps

Terrain suitability dataset description
All evaluated crops belong to the category of ‘upland crops.’ Terrain suitability for these crops was assessed based on local land slope, derived from the 30 m resolution SRTM DEM. The method for translating slope values into terrain suitability scores is detailed in Section 2.2.3 of Publication 115b (2018).

Two sets of terrain suitability scores were considered: one for the current climate and another for the projected climate in 2050. At lower slope levels, the scores remain unchanged. However, for slopes exceeding 8%, the suitability scores under the 2050 climate scenario are lower than those under current conditions. This adjustment accounts for the expected increase in rainfall intensity due to climate change.

MW02.89. Terrain suitability for upland crops under baseline 1960-1990 rainfall intensity
MW02.90. Terrain suitability for upland crops under assumed future rainfall intensitySoil suitability maps

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