Annex A

The characteristics of the soil groups

Code Soil type Brief description
AC Acrisols These are soils that are characterized by low activity clay. Most extensive on acid rock weathering, notably in strongly weathered clays, which are undergoing further degradation. Low-input farming on Acrisols is not very rewarding. Undemanding, acidity-tolerant cash crops such as pineapple, cashew or rubber can be grown with some success.
AN Andosols These are black soils of volcanic landscapes. Parent material is mainly volcanic ash. Andosols have a high potential for agricultural production
AR Arenosols Soils having a texture, which is loamy sand or coarser to a depth of at least 100 cm from the soil surface. Arenosols occur in vastly different environments and possibilities to use them for agriculture vary accordingly. All Arenosols have a coarse texture, accountable for the generally high permeability and low water and nutrient storage capacity. Arenosols are further marked by ease of cultivation, rooting and harvesting of root and tuber crops.
CM Cambisols Medium and fine-textured materials derived from a wide range of rocks, mostly in colluvial, alluvial or aeolian deposits. Cambisols make good agricultural land and are intensively used. The Eutric Cambisols are among the most productive soils on earth. Cambisols on steep slopes are best kept under forest; this is particularly true for Cambisols in highlands.
FR Ferralsols Red and yellow tropical soils.  Parent material: strongly weathered material on old, stable geomorphic surfaces; more in weathering material from basic rock than in siliceous material. Have low water holding capacity. The chemical fertility of Ferralsols is poor; weatherable minerals are absent and cation retention by the mineral soil fraction is weak.
FL Fluvisols Soils developed in alluvial deposits. Environment: periodically flooded areas alluvial plains, river fans, valleys and (tidal) marshes. Fluvisols are normally planted annual crops and orchards and many are used for grazing. Flood control, drainage and/or irrigation are normally required.
GL Gleysols Gleysols holds wetland soils that, unless drained, are saturated with groundwater for long enough periods to develop a characteristic “gleyic colour pattern”. Parent material consists of a wide range of unconsolidated materials, mainly fluvial, marine and lacustrine sediments of Pleistocene or Holocene age, with basic to acidic mineralogy. Adequately drained Gleysols can be used for arable cropping, dairy farming or horticulture.
LT Lithosols Lithosols, which are found in all the agroecological zones of Africa, are very shallow, occurring mainly on steep slopes often with exposed rock debris. These soils are at risk of very severe erosion.
LV Luvisols Soils in which clay is washed down from the surface soil to an accumulation horizon at some depth. Parent material is a wide variety of unconsolidated materials including glacial till, and aeolian, alluvial and colluvial deposits. Luvisols are fertile soils and suitable for a wide range of agricultural uses.
NT Nitosols Nitisols accommodates deep, well-drained, red, tropical soils with diffuse horizon boundaries and a subsurface horizon with more than 30 percent clay and moderate to strong angular blocky structure elements. Nitisols are predominantly found in level to hilly land under tropical rain forest or savannah vegetation. Nitisols permit deep rooting and make these soils quite resistant to erosion. The good workability of Nitisols, their good internal drainage and fair water holding properties are complemented by chemical (fertility) properties that compare favourably to those of most other tropical soils.
PL Planosols Planosols holds soils with bleached, light-coloured, eluvial surface horizon that shows signs of periodic water stagnation with abrupt textural discontinuity. Many planosols areas are not used for agriculture.
PZ Podzoluvisols Podzol has an ash-grey, strongly leached eluvial horizon under a dark surface horizon with organic matter, and above a brown to very dark brown. The low nutrient status, low level of available moisture and low soil-pH make Podzols unattractive soils for arable farming. Podzols have some potential for forestry and extensive grazing.
RG Regosols Soils with no significant profile development. Regosols are extensive in eroding lands, in particular in arid and semi-arid areas and in mountain regions. They are not used for cultivation but mainly serve as source of murram for various civil works.
SC Solonchaks The most extensive occurrences of Solonchaks are in inland areas where evapotranspiration is considerably greater than precipitation, at least during a greater part of the year. Salts dissolved in the soil moisture remain behind after evaporation/transpiration of the water and accumulate at the surface of the soil or at some depth. Excessive accumulation of salts in solonchaks affects plant growth.
VR Vertisols Vertisols are heavy clay soils with a high proportion of swelling. These soils form deep wide cracks from the surface downward when they dry out, which happens in most years. Vertisols become very hard in the dry season and are sticky in the wet season. Vertisols are productive soils if properly managed.
X Xerosols Aridic (dry) soils. A horizon and an aridic moisture regime; lacking permafrost within 200 cm of the surface.
Y Yermosols Aridic (dry) soils, soil horizon that is typical of deserts. A horizon and an aridic moisture regime; lacking permafrost within 200 cm of the surface.