Journal Article

PreJuSER-5525

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Solute Spreading under Transient Conditions in a Field Soil

Kasteel, R.FZJ* ; Pütz, T.FZJ* ; Vanderborght, J.FZJ* ; Vereecken, H.FZJ*

2009
SSSA Madison, Wis.

This record in other databases:  

Please use a persistent id in citations: doi:10.2136/vzj2008.0024

Abstract: Lateral mass redistribution in soils is the key to understanding field-scale solute transport, but the underlying assumptions of common transport theories are violated under transient-flow conditions. We tested the applicability of two limiting cases for solute spreading under transient-flow conditions in the field after an appropriate time coordinate transformation: no lateral mass redistribution, described by the convective-lognormal transfer function (CLT), vs. perfect lateral mass redistribution, described by the convection-dispersion equation (CDE). A Br- transport experiment performed in six zero-tension lysimeters and in the field for almost 3 yr under atmospheric conditions. Sampling the field was performed by extracting soil cores during seven campaigns. According to time-domain reflectometry only slight variations in water content were measured in space and time in the lysimeters. In contrast, water was lower and more variable in the plow layer in the field. The variance of solute spreading was better predicted by the CDE assuming perfect lateral mass redistribution. This hints at the importance of molecular diffusion. Both have the flexibility to fit the flux-averaged breakthrough curve in the lysimeters and the averaged concentration profiles in the field, but not with one set of parameters. The CLT parameters obtained from the lysimeter experiment better predicted the measured concentration profiles in the field for shorter times, but both models failed for longer Due to the occurrence of local saturation at the lower boundary of zero-potential lysimeters, differences in water hamper the transferability of transport parameters from lysimeters to the field.

Keyword(s): J

Note: This study was carried out in cooperation with the Agricultural Center Monheim, Bayer CropScience, Monheim, Germany. We would like to thank Drs. B. Brumhard, K. Scholz, H. Schafer, and A. Stork of Bayer CropScience for fruitful discussions during this project. We are also grateful to Drs. A. Wustemeyer and R. Kaiser from the former Institute of Radioagronomy: ICG-5 at Forschungszentrum Julich for designing and carrying out the experimental field work.

---

Research Program(s):

1. Terrestrische Umwelt (P24)

Appears in the scientific report 2009

---