This study examined the impact of increased infiltration rates on the transport and degradation of the herbicide atrazine in agricultural soils. Column and microcosm experiments were conducted using soils from Nebraska. The results showed that at higher infiltration rates, atrazine transport increased but degradation also increased due to higher soil moisture levels. Overall, atrazine transport was not significantly influenced by the higher infiltration rates because the enhanced degradation limited its movement. The findings suggest that the direct impacts of climate change on contaminant transport in soils are complex and depend on competing degradation and transport processes.

1. Renys Barrios1, Omkar Gaonkar2, Shannon Bartelt-Hunt1, Xu Li1, Daniel
Snow3, Yusong Li1
1Department of Civil Engineering, University of Nebraska-Lincoln
2 Department of Civil Engineering, Indian Institute of Technology – Madras
3Water Sciences Laboratory, University of Nebraska-Lincoln
ENHANCED BIODEGRADATION OF
ATRAZINE AT HIGH INFILTRATION RATES
Photo Eric Vance, US EPA

2. PROJECT MOTIVATION
Linkages between agriculture and groundwater quality will likely change in the
future due to climate variability; diversity of agricultural contaminants; and land use
changes
How do the direct impacts of climate change influence
atrazine transport in the vadose zone in a region with historic
atrazine application?

3. STUDY LOCATION
Central Platte Natural Resources
District and the Nebraska
Management Systems Evaluation
Area (MSEA)

4. EXPERIMENTAL TASKS
• Column experiments to evaluate atrazine and atrazine
metabolite transport at a range of infiltration rates
• Batch microcosm studies were also conducted to examine
the effect of moisture content on atrazine degradation
• One-dimensional transport modeling to simulate column
breakthrough

5. ATRAZINE TRANSPORT THROUGH COLUMNS
sandy loam
soil
loam
soil

6. BATCH BIODEGRADATION MICROCOSMS

7. CONCLUSIONS
• The direct influence of climate on organic contaminant
transport in the subsurface is not immediately obvious
• Higher infiltration rates may enhance transport
• Higher soil moisture content may enhance degradation
processes
• In this study, atrazine transport was not significantly influenced
by climate, as enhanced degradation with increasing moisture
content limited the impact of more rapid infiltration

8. OUTPUTS
PUBLICATIONS
• Barrios, R.E.; Akbariyeh, S.; Gani, K.N.; Kovalchuk, M.T.; Park, J.; Li, X.; Li. Y.; Thompson, E.; Rosenbaum, D.;
Snow, D.; Tang, Z.; Gates, J.; Bartelt-Hunt, S.L. Climate change impacts the subsurface transport of trace organics
originating from agricultural production activities. Submitted on November 16, 2017 to Climate Dynamics
• Barrios, R.E.; Gaonkar, O.; Snow, D.; Li, Y.; Bartelt-Hunt, S.L.; Li, X. Enhanced biodegradation of atrazine at high
infiltration rates in agricultural soils. Planned to be submitted by May 2018 to Science of the Total Environment
POSTERS AND PRESENTATIONS
• Barrios, R.E.; Gaonkar, O; Bartelt-Hunt, S.L.; Li, X.; Snow, D.D.; Li, Y. Influence of climate on subsurface atrazine
degradation and transport. American Chemical Society Meeting, New Orleans, LA, March 18-21, 2018.
• Barrios, R.E.; Bartelt-Hunt, S.L.; Li, X.; Li, Y.; Snow, D.; Gaonkar, O. Influence of infiltration rate on atrazine transport
on agricultural soils. Nebraska Annual Water Symposium, Lincoln, NE, October 26-27, 2017.
• Barrios, R.E.; Akbariyeh, S.; Bartelt-Hunt, S.L.; Li, X.; Li, Y.; Zhang, Y.; Gani. K.M. Influence of climate change on
trace organic fate in the subsurface. 2017 AEESP Research and Education Conference, Ann Arbor, MI, June 20-22,
2017.
• Akbariyeh, S.; Gomez Pena, C.A.; Barrios, R.E.; Li, X.; Bartelt-Hunt, S.L.; Li, Y. Impacts of climate change on nitrate
transport beneath a center-pivot irrigated corn field. 2017 AEESP Research and Education Conference, Ann Arbor,
MI, June 20-22, 2017.

9. QUESTIONS?
renysbarrios7@gmail.com
Support for this project was provided by USDA NIFA
(Grant number 2014-67003-22072) and the Robert B.
Daugherty Water for Food Global Institute at the
University of Nebraska