Abstract. Sandy soils with fragipans are usually considered poorly suited for
agriculture. However, these soils are cultivated in Namibia as they can
secure a minimum harvest during droughts. In order to understand the
hydrological influence of fragipans in these soils, Ehenge, their soil moisture
content was measured for 4 months. These data were then compared to a
deep soil without fragipan, Omutunda, which is more productive during normal years
but less productive during droughts. The results illustrate that the combination of sandy topsoil and shallow
fragipan has beneficial effects on plant-available water during dry periods. Three reasons can be determined: (i) high infiltration rate in the sandy
topsoil, (ii) prevention of deep drainage by the fragipan, and (iii)
limitation of evaporation losses through the sand. Consequently,
transferring these findings to other dry, sandy areas with fragipans, with
respective consequences on farming practices, crop productivity, and food
security, should be possible.