Impact of roots on ground water quality

Timothy J. Gish, Daniel Gimenez, Walter J. Rawls

Research output: Contribution to journalArticlepeer-review

38 Scopus citations

Abstract

Preferential flow is perhaps the major chemical transport process influencing the rapid and typically unexpected movement of agricultural chemicals to ground water. Plant roots are a major contributor to preferential flow mechanics as they form spatial voids which can be used as preferential flow pathways. Chemical transport of atrazine, deethylatrazine, and bromide solutions concentrations under tilled and no-tilled corn fields was evaluated below the active root zone. Additionally, the impact of roots on flow pathways was visualized using a soluble dye (Brilliant Blue FCF). Pictures of the dye-stained pattern were subsequently digitized to determine the crosssectional area used for transport as a function of depth. Bromide transit times through the field soils were not influenced by tillage practice, whereas atrazine transport was strongly influenced by tillage practice. Under no-till field conditions, atrazine was rarely detected but deethylatrazine concentrations were greater than those observed under tilled field conditions. Visual observation indicated that the dye under no-tillage was more predominant in the corn row, indicative of transport through void root channels. No-tillage practices may decrease the likelihood of ground water contamination through leaching due to the formation of stable root channels where an organic carbon source and microbial population are preferentially located to degrade pesticides.

Original languageEnglish (US)
Pages (from-to)47-54
Number of pages8
JournalPlant and Soil
Volume200
Issue number1
DOIs
StatePublished - 1998
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Soil Science
  • Plant Science

Keywords

  • Chemical transport
  • Pesticide behavior
  • Preferential flow

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