Hydraulic properties of dryland soils of Usmanu Danfodiyo University Teaching and Research Farm, Sokoto, Nigeria

Abstract

Water characteristics of dryland sandy soils could have greater impact in explaining the low yield of the soils due to its very high infiltration rates. Sandy soils have low organic carbon (OC), low CEC and higher bulk density (Db), infiltration rate and saturated hydraulic conductivity (Ksat). The study was setup to evaluate some physical properties and the infiltration and saturated hydraulic conductivity (Ksat) of the dryland soils under conventional tillage. Randomised completely block design was used with six (6) sampling spots as the treatments at two (2) different depths (0-15 and 15-30 cm), totalling 36 samples. Infiltration study was carried out in situ with aid of double ring infiltrometer while Ksat was determined in the lab using undisturbed cores. The texture of the soil was found to be sand in 0-15 cm depth and loamy sand in the 15-30 cm depth. Significant (p<0.05) higher Db, Ksat and lower TP and OM were obtained in spots A and B which differed significantly from C and E. Following a t-test, 0-15 cm had a higher Ksat (13.3 cm hr^-1), organic matter (1.73%), porosity (46.7%) and lower Db (1.41 Mg m^-3) which differed significantly (p<0.05) from 15-30 cm depth. Significant (p<0.05) higher initial infiltration rate, cumulative infiltration and steady state infiltration rates were obtained in spots labelled A and F. Simple linear regression analysis showed that sand and OM content are important factors that determine Ksat positively and negatively respectively at both sampling depths. Conclusively, adoption of conservation tillage practices such as no-tillage would improve the water transmission and physical properties there by reducing leaching and increasing the plant available water content of the soils and consequently improve the soil productivity and minimize erosion.