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In northern Burkina Faso (West Africa), a study was undertaken to explore the possibilities of restoring the infiltration capacity of crusted soils through the stimulation of termite activity. Treatments consisted of the application of a mulch of a mixture of wood and straw without insecticides (resulting in “termite plots”) and the application of the same mulch and an insecticide (Dursban with chloropyrifos as the active ingredient) to prevent termite activity (resulting in “non-termite plots”). Three rainfall simulations of 60 minutes duration with an intensity of 50 mm/h at an interval of 24 hours between the first and the second and 72 hours between the second and third simulation were applied, to study the effect of consecutive showers on termite-modified soil characteristics. Cumulative infiltration amounts, final infiltration rates, soil water content and porosity were larger and bulk density was smaller on termite plots as compared to non-termite plots. This suggests that termites may be an important agent in soil-crust control and in the improvement of soil physical properties in Sahelian ecosystems.

Hedgerows of Cassia siamea were planted 4 m apart in a maize/cowpea rotation on a 14% slope of a Lixisol/Alfisol in 1988 at Machakos, Kenya. Infiltration rates were measured in situ across hedgerow barriers with a drip infiltrometer. During the dry season the steady infiltration rate under the hedgerows was 135 mm h −1 while on the alleys in between it was 41–49 mm h −1 and on the control plot 39–48 mm h −1 . Corresponding values for the wet season were 69 mm h −1 for the hedge and 8–11 mm h −1 for the alley. Removal of the hedge plants revealed that much of the increase is due to significantly more macropores in the topsoil beneath the hedgerow than in the topsoil beneath the alley. Differences in pore size distribution in the subsoil were small and not significant. Total increase in average infiltration rate of the hedgerow barrier system in the dry season is 30% and in the wet season is 94% as compared to the alley. The combined effect of above- and below-ground changes makes hedgerow barriers valuable for runoff control.