Abstract:The aim of this study is to improve our understanding of the temporal and spatial variations of soil water repellency, in particular those of agricultural lands where its economic and environmental impacts can be particularly severe. Variations in water repellency severity were studied with particular emphasis as to the role therein of the micro-topographic differences between furrows and ridges.Topsoil water repellency was monitored over a 1-year period at about monthly intervals and on some additional occasions in an agricultural field involving three land-use phases (potatoes, maize, fallow) in the Dunas de Vagos area, north-central Portugal. Water repellency severity was measured in situ at soil depths of 2-3 and 7-8 cm using the molarity of an ethanol droplet (MED) test, and accompanied by soil moisture measurements using a ThetaProbe. Under potatoes as well as maize, these measurements were carried out on ridges and in furrows separately.The results confirmed the transience of soil water repellency, which changed markedly within periods as short as 2 weeks. Although substantial changes in water repellency severity occurred, repellency was present over a large part of the monitoring period under potatoes, maize and fallow. Repellency severity was found to regularly differ significantly between furrows and ridges as well as between 2-3 and 7-8 cm depth. Soil moisture content was found to be an important factor, but by itself not sufficient to account for the observed temporal variations. Other temporally variable factors (e.g. microbial and root activity) might contribute to the variations in water repellency at this agricultural site under rotating crops.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.