Spatial variation of infiltration rate and related soil properties in a central Gezira clay soil II. Geostatistical methods
2001
Mustafa, M.A. | Ibrahim, A.A. (University of Khartoum, Shambat (Sudan). Faculty of Agriculture)
The spatial variation of steady-state infiltration rate (IR), clay content, EC, CaCO3, SAR and PH (paste) at 5-m regular intervals, along two 500-m long transects (S-N, W-E) crossed in the middle were studied in two sites (Kubur and Talha) using geostatistical techniques. The data of the two transects were pooled for each site. An average and a 2-dimentional IR semi variograms were computed for Kubur site. The former semi-variogram gave a better accountability to spherical model han the letter. Thus, average semi-variograms fitted the spherical model except that of clay content at Kubur site, which fitted a linear model. The parameters of the two models are provided and may be used in kriging. All semi-variograms exhibited nugget variances, indicating micro-scale spatial variability. The ranges for CaCO3, EC, clay content, PH (paste, IR and SAR were 116, 58, 56, 53, 50 and 31 m, respectively. The cross semi-variogram for IR versus clay content, EC, SAR, or CaCo3, are presented for both sites. The cross semi-variogram in Talha site showed that IR decreased with increase of clay content, and the relationship decreased with increase in lag distance. Other cross semi-variograms indicated lack of relationship between IR and the other soil properties
显示更多 [+] 显示较少 [-]