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[1] In this paper we describe a simple and quick method for determining the presence of water repellency in a soil by using a small core sampler (1.5 cm in diameter, 25 cm long) and applying the water drop penetration time (WDPT) test at different depths on the sandy soil cores. Obtained results provide spatial distribution patterns of water repellency in a soil profile, demonstrating seasonal changes in repellency. An advantage of the method is that the soil is not disturbed by the sampling. For assessment of the persistence of water repellency in strongly to extremely water repellent soils, and for determination of the critical soil water contents, the WDPT test and volumetric water content determinations should preferably be performed in the laboratory.

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The vadose zone plays an essential role in all types of processes that occur in the soil. Modelling of the processes in the vadose zone helps to understand and quantify effects of, for example, land use, irrigation, salinity and climate changes. Version 2 of SWAP (soil–water–atmosphere–plant) is a numerical model that simulates the (interaction between) one‐dimensional soil moisture, heat and solute transport in the topsoil layers. The influence of all these processes on crop growth may be simulated as well. This article describes briefly some of the options the program offers. The results of a sensitivity analysis are discussed, followed by a case study on variations in soil salinity in a coastal area. Copyright © 2000 John Wiley & Sons, Ltd.