Variation of Soil Chemical Properties Over Nigerian Savanna

Abstract

An analysis of relationships between selected soil chemical properties and parameters of parent material, climate and relief was undertaken for the savanna of north central Nigeria. Step by step examination of individual properties and the environmental parameters reveals numerous invariably disparate relationships often explicable in terms of local conditions. However, an analysis of covariance involving all variables shows that variations in base elements and cation exchange capacity are more strongly related to lithology than climatic or relief parameters. Soil pH and base saturation percentage, on the other hand, are influenced more by rainfall than parent material, altitude and slope position. Temperature and slope gradient are relatively unimportant in the variability of all soil properties. On the whole, the soil properties show significantly greater values over basalt, shale and alluvium than gneiss, schist and colluvium which in turn show greater values than sandstone, granite, granite gneiss, aeolian and ironpan‐rich deposits. Exchangeable cations and cation exchange capacity increase with an increase in rainfall, altitude and downslope position while pH and base saturation per cent show a decreasing trend.

Suitable Models for Describing Sulphate Desorption Kinetics in Selected Bauchi North Soils of Varying Parent Materials in the Nigerian Sudan Savanna

“…Such differences are expected since the soils developed from different parent materials. This observation corroborates the findings of Jaiyeoba (2006) for soil derived from different parent materials in Nigeria.…”

Spatial variability of uncultivated soils in derived savanna

“…The CEC differed among the locations, with higher values at Nsukka on a higher altitude than at Obimo and Ibagwa-aka on lower altitudes, probably due to local lithological modifications arising primarily from the small differences in altitude (Jaiyeoba, 1996). The CEC was higher under the secondary forest than under the grassland and bare-soil fallows for which values were similar, thus suggesting that maintenance of grassland fallow does not improve soil fertility over bare-soil fallow.…”

“…The negligible differences in soil pH among the locations could be due to the similarity in the parent material and rainfall amount (Jaiyeoba, 1996). Again, the similarity in pH among the land uses suggests that the soils are of high buffering capacity.…”

Spectral estimation of wetland carbon dioxide exchange

“…The factors contributed to the variability in the soil CEC in the order location > land use > depth zone. The CEC differed among the locations, with higher values at Nsukka on a higher altitude than at Obimo and Ibagwa-aka on lower altitudes, probably due to local lithological modifications arising primarily from the small differences in altitude (Jaiyeoba, 1996). The CEC was higher under the secondary forest than under the grassland and bare-soil fallows for which values were similar, thus suggesting that maintenance of grassland fallow does not improve soil fertility over bare-soil fallow.…”

“…The spatial variability in soil pH was low compared with that in the SOM concentration and CEC of the soils (Table 4). The negligible differences in soil pH among the locations could be due to the similarity in the parent material and rainfall amount (Jaiyeoba, 1996). Again, the similarity in pH among the land uses suggests that the soils are of high buffering capacity.…”