The Soil Meiqfauha of The Accra Plains

Abstract

Samples of soil have been taken from various situations at different times to illustrate the effects of season, water, sha.de, agriculture, disturbance and type of soil, on the soil meiofauna of the Accra Plains, It is shown that there is a significant difference both in numbers and in vertical distribution of the animals in different seasons and in different soils. Water is thought to be the most important factors as it is demonstrated that there is a direct correlation between size of population and the rainfall of the previous month, and that the vertical distribution can be correlated with the rainfall of the same month. Waterlogging however causes a reduction of population. Shade produces a marked effect on both the numbers and the vertical distribution, the population, with the exception of the Acarina, being smaller and deeper in exposed than in shaded bare fallow soil, ThiB is almost certainly caused by the desiccation conditions in the exposed soil. Disturbance of the soil by argicultural practices causes a reduction of population, and this smaller population persists during crop growing, and after

harvest when, the plot is allowed to return to grass. Disturbance causes a rapid drying out of the soil, the crop does not give enough cover, ana harvesting causes impoverishment of the soil# Each of these conditions is shown to reduce the population* Different kinds of soil are shown to "be associated with a difference in sige and distribution of population. In both dry and wet seasons, the population of latosol is greatest* clay lowest and sand intermediate* During the dry season the population of latosol is found deeper than in the other two soils. It is suggested that this is because there is more food and water at lower levels in the latosol. This enables the animals to avoid the desiccation conditions in the upper layers, and to form a reservoir for a large population increase under the improved conditions of the wet season*