Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Movement of water and the herbicides atrazine and isoproturon through a large structured clay soil core.
AU - Beck, Angus J.
AU - Lam, Venessa
AU - Henderson, D. Edward
AU - Beven, Keith J.
AU - Harris, Graham L.
AU - Howse, K. Roger
AU - Johnston, A. E. Johnny
AU - Jones, Kevin C.
PY - 1995
Y1 - 1995
N2 - A large (1.1 m × 0.8 m in diameter) core of strongly cracked clay soil was instrumented with eight suction samplers, ten zero-suction samplers and sixteen pressure transducer tensiometers. Results of three rainfall events labelled with potassium bromide, pentafluorobenzoic acid and 2,6-difluorobenzoic acid indicate rapid bypass flow, matrix advection and mixing of water between the soil macropores and the matrix all occurred. Generally, no sharp distinction was observed between crack flow and matrix advection; water flow was best described by a continuum of flow phenomena. Before rainfall application, the herbicides atrazine and isoproturon were applied to the soil surface at rates typically used in the field (2.475 kg active ingredient/ha). Rapid bypass flow in large cracks, by which some of the solutes were transported with limited contact with the soil, was mainly responsible for redistribution of the herbicides and their movement to depth in short time periods. Over the course of the experiments 0.23 pore volumes of rainfall were applied to the core but only 0.02 pore volumes were recovered by gravity drainage. Less than 1% of the herbicides applied was lost in water draining from the soil core.
AB - A large (1.1 m × 0.8 m in diameter) core of strongly cracked clay soil was instrumented with eight suction samplers, ten zero-suction samplers and sixteen pressure transducer tensiometers. Results of three rainfall events labelled with potassium bromide, pentafluorobenzoic acid and 2,6-difluorobenzoic acid indicate rapid bypass flow, matrix advection and mixing of water between the soil macropores and the matrix all occurred. Generally, no sharp distinction was observed between crack flow and matrix advection; water flow was best described by a continuum of flow phenomena. Before rainfall application, the herbicides atrazine and isoproturon were applied to the soil surface at rates typically used in the field (2.475 kg active ingredient/ha). Rapid bypass flow in large cracks, by which some of the solutes were transported with limited contact with the soil, was mainly responsible for redistribution of the herbicides and their movement to depth in short time periods. Over the course of the experiments 0.23 pore volumes of rainfall were applied to the core but only 0.02 pore volumes were recovered by gravity drainage. Less than 1% of the herbicides applied was lost in water draining from the soil core.
U2 - 10.1016/0169-7722(95)00016-O
DO - 10.1016/0169-7722(95)00016-O
M3 - Journal article
VL - 19
SP - 237
EP - 260
JO - Journal of Contaminant Hydrology
JF - Journal of Contaminant Hydrology
IS - 3
ER -