Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/S0016-7061(02)00178-7
Title (Primary) Multiple tracing of fast solute transport in a drained grassland soil
Author Stamm, C.; Sermet, R.; Leuenberger, J.; Wunderli, H.; Wydler, H.; Flühler, H.; Gehre, M.
Source Titel Geoderma
Year 2002
Department ISOBIO
Volume 109
Page From 245
Page To 268
Language englisch
Abstract Fast transport of fertilizers and other agrochemicals into subsurface drainage systems has been recognized as a serious threat to surface waters. We report on a tracer experiment carried out on a 7.3×20 m2 plot on a loamy grassland soil to determine the flow paths to a tile drain at 1 m depth. The experiment consisted of a series of consecutive tracer applications including seven solutes and liquid manure that were applied either on the entire plot or on limited bands. Based on the discharge behavior under natural conditions, we estimated the effective hydraulic conductivity of the subsoil to be in the order of 8–29 cm day−1. Under experimental conditions, the soil transmitted 120 mm day−1 into the subsurface drain and two vertical profiles without producing surface runoff. Only part of the soil water, corresponding to 6–27 mm of the soil depth, contributed to the fast hydrological response. The transport of the tracers was very fast. Within 7–16 h after application of the conservative Br, Cl and HDO and the slightly sorbing substances brilliant blue (BB) and amino-G-acid (AG), these tracers reached relative concentrations in the outflow between 19% and 35% of the input concentrations. From the mass balance for water and solutes, it follows that the tracers were quickly transported over lateral distances of several meters. The manure constituents dissolved reactive P (DRP), NH4+ and Cl, applied as liquid manure on the surface on a 1 m wide band above the tile drain, reached the drain within 5 min after application. After the early peak of DRP and NH4+, their concentration in the drain decreased quickly to background levels, whereas Cl exhibited a second peak. Despite the fast transport and the small soil volume conducting water and solutes, the interaction between irrigation water and soil matrix was intimate enough to retain the two sorbing tracers. From the stained flow paths, the hydrologic behavior of the field under natural conditions and the hydrometric data during the experiment, it follows that the fast lateral tracer transport occurred mainly close to soil surface and not through the subsoil. Only in the immediate vicinity of the tile drain and of two lateral pits at the edge of the experimental plot water was redirected downwards and discharged from the tile drain and the bottom parts of the profiles, respectively. Hence, effluent from tile drains may not be representative for water reaching the subsoil or shallow ground water in undisturbed soils.
Persistent UFZ Identifier
Stamm, C., Sermet, R., Leuenberger, J., Wunderli, H., Wydler, H., Flühler, H., Gehre, M. (2002):
Multiple tracing of fast solute transport in a drained grassland soil
Geoderma 109 , 245 - 268 10.1016/S0016-7061(02)00178-7