Investigation of physical and hydrological characteristics of the Lismore stony silt loam

Abstract

Lismore stony silt loam constitutes a large part of the Central Canterbury Plain which has still to be developed for irrigation. Little quantitative information exists concerning the physical and hydrological parameters of this soil. In this study these aspects were investigated over a range of soil depths and soil moistures.

While the composition of the soil varied little, the volume of stones was greatest in the shallower soil. Associated with this were lower bulk densities and lower water-holding capacities.

Irrigation experiments showed that percolation of water down the soil profile was erratic, and inconsistent with antecedent moisture conditions. The wetting front zone was diffuse and water tended to travel via preferred routes.

Moisture loss following irrigation was most rapid in the shallow, stony soil. Evapotranspiration provided the energy for soil-water extraction, and redistribution of soil-water was negligible.