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A lysimeter experiment to investigate the effect of surface sealing on hydrology and pesticide loss from the reconstructed profile of a clay soil. 1. Hydrological characteristics
Author(s) -
Heppell C.M.,
Chapman A.S.,
Bidwell V.J.,
Forrester G.,
Kilfeather A.A.
Publication year - 2004
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.2004.tb00386.x
Subject(s) - throughflow , lysimeter , macropore , hydrology (agriculture) , environmental science , soil science , water content , soil horizon , surface runoff , infiltration (hvac) , water table , geology , soil water , water flow , tensiometer (surface tension) , geotechnical engineering , groundwater , chemistry , catalysis , mesoporous material , ecology , surface tension , biochemistry , physics , thermodynamics , quantum mechanics , biology
. A laboratory experiment was designed to assess the impact of surface seal development on the hydrological response of a clay soil. The influence of surface sealing on vertical macropore flow and lateral throughflow was of particular interest. The extent and development of the surface seal in repacked lysimeters was designed to match that recorded over two growing seasons at a clay field site in Essex, and was not extensive enough to reduce significantly the infiltration capacity of the soil. Consequently, the hydrological response of the lysimeters was similar under sealed and unsealed conditions, with a more rapid wetting response under sealed conditions being attributed to the higher soil moisture content required to create the surface seal. Macropore flow was initiated at the A/B soil boundary of the lysimeters, in response to the development of a saturated layer. The rate of macropore and throughflow in the soil was dictated by rainfall intensity at the soil surface as this controlled the depth of water in the perched water table. Simulation of the tensiometer response in the lysimeters demonstrated that it was possible to attribute the rapid movement of water through the A horizon to water displacement processes alone, without recourse to preferential flow processes.