Abstract:
Grid method approach was adapted to conduct a detailed soil survey to characterize and rate the
suitability of Tse-Tswam and Tse-Ordam soils. Three profiles pit were dug in each site and
morphologically described. Samples collected from genetic horizons were analysed and
parametric evaluation method used to evaluate the soils' suitability for surface and subsurface
irrigations. Results show: profiles were deep (118cm) to very deep (200cm); well to imperfectly
drained; sandy loam/loamy sand to sandy clay loam textures and weak fine crumb to moderate
fine-coarse subangularblocky structures with slopes between 0 to 3%; indicating almost flatland
surface The soils had medium - high sand (49.99-83.00%), low - medium clay (14.58- 35.13%)
and low silt (10.65-16.96%) fractions. The soils were slightly acid (5.96-6.05); low in organic
carbon (0.45-0.60%), nitrogen (0.08-0.10%), Available phosphorus (4.70-5.85%) and EC (0.12-
0.13dms-1
); very low CEC (6.91-8.60cmolkg-1
), CaCO3 (0.00-2.00%) with medium to high in
base saturation (50.97-79.38%). ESP(1.13-1.77%) shows the sites were not characterized by
excessive degree of saturated extract with exchangeable sodium (ESP > 15 percent and pH ?
8.5), therefore, cannot be alkali (Sodic)/ saline and therefore highly suitable for irrigations. The
lands have no limitations with regards to depth, CaCO3, electrical conductivity and slope thereby
qualifying these parameters into highly suitable (S1) subclass; the soils were optimal for all types
of irrigation. For the surface irrigation; soil units 1, 11. 111 and V1 were rated as moderately
suitable (S2w) due drainage defects, units 1V and V were rated highly suitable (S1) as no
parameters had substantially reduced their irrigation suitability. For the drip or localized
irrigation, all the soil units 1 to V1 were highly suitable, even the limitations due to drainage
defect did not substantially reduced the soils' suitability for the subsurface irrigation. |
