Spatial Variability Analysis of Selected Soil Properties at Musayab, Babil, Iraq

Abstract

Great Musayab projectwas chosen to assess spatial variability of some soil properties,and furthermore,to investigate its implications for sampling design. Two hundred and forty composited soil samples werecollected acrossthe project and thesurrounding areas. Soil properties including electrolytic conductivity (ECe),calcium carbonate (CaCO3), cation exchange capacity (CEC),as wellas sand, silt, and clay were analyzed for each sample. Classic statistical analysis showed that ECe had the highest CVwhichwas caused by some unusually high measurements. Semivariograms of allproperties were constructed,and compared to estimate thespatial variability of the soilproperties in the area. Thesemivariograms of soilproperties were best describedby aexponential model. Geo-statistical analysis showed that all the soil properties had a moderate or strong spatial dependency. Ordinary kriged maps indicated soils with high ECe, CEC, CaCO3, sand, silt, and clay in the surface horizons were found in the southern parts of the project. Water flows may be the dominant driving force for the spatial variability of chemical properties and texture parameters, implying more samples or analysis are required to achieve a similar level of precision.