A field method to determine three dimensional infiltrability of vineyard soils

Abstract

A method is described to measure water intake from a small, shallow pond in which a 5 mm constant water head is maintained. Since water is supplied to the soil at near atmospheric pressure, infiltrability rather than infiltration rate is determined. Furthermore, water intake occurs in three dimensions, which simulates water intake under drippers. Therefore, the water intake process can be regarded as three dimensional (3-D) infiltrability. The small pond also simulates a condition often encountered in practice. Hence, 3-D infiltrability, expressed as litres per hour, will give an indication of dripper discharge rates that will cause water infiltration problems. Three-D infiltrability, measured in four vineyards showed that this parameter could vary significantly between vine banks and inter row spaces. The method was capable of measuring 3-D infiltrabilities that varied from 0.4 Mr1 to 14.0 1. h−1. Unlike more conventional infiltration methods, this method allows measurement of water intake on vine banks where water is supplied in most irrigated vineyards. The method also has a further advantage that the surface is completely undisturbed during an infiltration run. It can also be used to determine whether a surface crust is responsible for poor water uptake under drippers or not. This can be useful in making decisions with respect to soil amelioration or irrigation management practices to improve water infiltrability.