Groundwater nitrate following installation of a vegetated riparian buffer.
Substantial questions remain about the time required for groundwater nitrate to be reduced below 10 mg L(-1) following establishment of vegetated riparian buffers. The objective of this study was to document changes in groundwater nitrate-nitrogen (NO3-N) concentrations that occurred within a few years of planting a riparian buffer. In 2000 and 2001 a buffer was planted adjacent to a first-order stream in the deep loess region of western Iowa with strips of walnut and cottonwood trees, alfalfa and brome grass, and switch grass. Non-parametric statistics showed significant declines in NO3-N concentrations in shallow groundwater following buffer establishment, especially mid 2003 and later. The dissolved oxygen generally was >5 mg L(-1) beneath the buffer, and neither NO3-N nor DO changed significantly under a non-buffered control area. These short-term changes in groundwater NO3-N provide evidence that vegetated riparian buffers may yield local water-quality benefits within a few years of planting.
National Institute of Public Health, 2-3-6, Minami, Wako, Saitama 351-0197 Japan. t-yamada@niph.go.jp
Toshiro
T
Yamada
Sally D
SD
Logsdon
Mark D
MD
Tomer
Michael R
MR
Burkart
D000383:Agriculture; D001673:Biodegradation, Environmental; D031724:Bromus / Q000254:growth & development; D003247:Conservation of Natural Resources; D005618:Fresh Water / Q000032:analysis*; D007484:Iowa; D000455:Medicago sativa / Q000254:growth & development; D009566:Nitrates / Q000032:analysis*; D014197:Trees / Q000254:growth & development; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
D009566:Nitrates; D014874:Water Pollutants, Chemical