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Field‐Scale Bromide Leaching as Affected by Land Use and Rain Characteristics
Author(s) -
Yang Yang,
Wendroth Ole,
Walton Riley Jason
Publication year - 2013
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2013.01.0018
Subject(s) - leaching (pedology) , environmental science , transect , macropore , soil science , hydrology (agriculture) , soil horizon , grassland , groundwater , spatial distribution , leaching model , soil water , geology , soil salinity , agronomy , chemistry , remote sensing , biochemistry , oceanography , geotechnical engineering , biology , catalysis , mesoporous material
Natural heterogeneity in soil properties limits the understanding on water and solute transport at a field scale. The objective of the current study was to adopt a new experimental design with scale‐dependent treatment distribution and to assess the impact of land use and rain characteristics on Br – leaching under field conditions. On a transect with two land use systems, that is, cropland and grassland, rainfall intensity and the time delay between solute application and subsequent rain were arranged in a repetitive pattern at different scales. Soil samples in 10‐cm increments down to 1‐m depth were collected along the transect for Br – analysis after rainfall simulation. Owing to continuous macropores, supporting the development of preferential flow, soil Br – was more evenly distributed with soil depth and reached greater depth in grassland. Increasing rainfall intensity enforced the deep leaching of Br – . Frequency‐domain analysis revealed that the dominant factor controlling Br – leaching varied with depth. At 0 to 10 cm, rainfall intensity was strongly correlated with Br – concentration; while in the soil layer below, application time delay was the main driver for the spatial distribution of Br – . With increasing soil depth, the spatial behavior of Br – was mainly caused by soil properties such as soil texture and topography, rather than rainfall characteristics. Nevertheless, rainfall intensity was found to be positively correlated with Br – concentration in deep soil, indicating a great risk of deep leaching and groundwater contamination under heavy rainfall. These results have direct implications for the surface application of chemicals.