Quantify Piston and Preferential Water Flow in Deep Soil Using Cl− and Soil Water Profiles in Deforested Apple Orchards on the Loess Plateau, China

摘要: Piston and preferential water flow are viewed as the two dominant transport mechanisms regulating terrestrial solute cycles. However, it is difficult to accurately separate patterns because not easy capture directly in field environments. In this study, we take advantage of afforestation induced desiccated deep soil, quantify piston using chloride ions (Cl−) soil profiles, four deforested apple orchards on Loess Plateau. The deforestation time ranged from 3 15 years. each selected orchards, there was a standing orchard that planted at same one, therefore used benchmark initial Cl− profiles orchard. detected migration front, measured via increase below front. Results showed zone, migrated deeper after deforestation, indicating layer formed by absorption deep-rooted trees did completely inhibit movement water. Moreover, an evident downward demonstrating existence under conditions. Although pore velocity small loess, still accounted for 34–65% total infiltrated This study presented regulate following through observations advanced our understanding hydrologic process soil.