| dc.description.abstract | Infiltration rates, saturated hydraulic conductivity (Ksat)
and antecedent water content (w) were investigated in Kabete
Nitisol and Kibwezi Lixisol under Forest, Grass, Cultivated Bare
and Compacted Bare Landuse as treatments. Comparison of soil water
release and retention of the same soils was made under Grass
(virgin) treatment. Infiltration tests were done in the dry and wet
soil moisture status referred to as dryrun (DR) and Wetrun (WR)
infiltration rates respectively using the double ring
infiltrometer. The soil physical variables (thought) to influence
the above hydraulic properties were also investigated. These
included organic carbon (OC) , bulk density (Pb) and texture.
The Pb, OC and Ksat showed significant differences at 5% level
with respect to site conditions and the two soil types. Treatment
textural variations were insignificant but for soil types Kabete
was predominantly clayey and Kibwezi predominantly sandy. The Ksat
for both areas revealed significant differences only in the Forest,
due to its high OC and lower Pb. There was no overall difference
between Ksat of Kabete and Kibwezi. The DR antecedent water in
order of decreasing magnitude for Kabete was Forest, Grass,
Cultivated and Compacted Bare site, but the results were somehow
distorted for Kibwezi due to irrigation. These observations were
significant at 5% level. In Kabete, the (newly) cultivated site had
the highest water intake rates, followed by Forest tben Grass and
lastly compacted site. In Kibwezi, the rates in decreasing order of
magnitudes were: Forest, Grass, Cultivated (and compacted by
machinery) and compacted site. Significant correlations (r) between
infiltration rates and OC, Pb and Ksat at selected times were
obtained for Kabete and Kibwezi.
In the Virgin site, significant differences (P<0.05) in soil
water retention and release were obtained. soil water retention in
the 0 - 1500 KPa range was significantly higt ':"(P<O. 05) under
Kabete Nitisol than under Kibwezi Lixisol. The opposite trend was | en |
