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ARS Home » Southeast Area » Booneville, Arkansas » Dale Bumpers Small Farms Research Center » Research » Publications at this Location » Publication #413100
Research Project: Sustainable Small Farm and Organic Grass and Forage Production Systems for Livestock and Agroforestry

Location: Dale Bumpers Small Farms Research Center

Title: Effects of conservation buffer systems on adsorption of fluorescent-labeled Escherichia coli

Author
item AL-AWWAL, NASRUDDEEN - University Of Missouri
item ANDERSON, STEPHEN - University Of Missouri
item EL-DWEIK, MAJED - University Of Missouri
item UDUWATTA, RANJITH - University Of Missouri
item YANG, JOHN - University Of Missouri
item ZAID, FARAJ - University Of Missouri

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2022
Publication Date: 1/16/2023
Citation: Al-Awwal, N., Anderson, S.H., El-Dweik, M., Uduwatta, R.P., Yang, J., Zaid, F. 2023. Effects of conservation buffer systems on adsorption of fluorescent-labeled Escherichia coli. Journal of Environmental Quality. https://doi.org/10.1002/jeq2.20436.
DOI: https://doi.org/10.1002/jeq2.20436

Interpretive Summary: The magnitude of bacterial transport through runoff into surface water or infiltration into groundwater is influenced by the adsorption processes in soil. The objective of this study was to evaluate fluorescent-labelled Escherichia coli (E. coli) adsorption by soils under agroforestry, grass buffer, and rowcrop management. The results indicated that agroforestry soils have greater E. coli adsorption capacity and the potential to mitigate the effects of E. coli transport to surface or groundwater through the soil ecosystems.

Technical Abstract: The magnitude of bacterial transport through runoff into surface water or infiltration into groundwater is influenced by the adsorption processes in soil. The objective of this study was to evaluate fluorescent-labeled Escherichia coli (E. coli) adsorption by soil under agroforestry buffer (AB), grass buffer (GB), and row crop (RC) management. Adsorption experiments were conducted by inoculating three masses (0.5, 1, and 10 g) of each treatment (AB, GB, and RC) with E. coli O157:H7-GFP with concentration ranges of 105–108 colony-forming units (cfu) ml-1. Adsorption data were evaluated using Langmuir, Freundlich, and Temkin adsorption isotherm models. The Freundlich isotherm model described the observed data well for all treatments using the 10-g soilmass, with the R2 values closer to unity in all treatments. The Freundlich Kf parameter, an indicator of adsorption capacity, was higher for the AB treatment (9.93 cfu ml-1) compared with the GB and RC treatments (2.32 and 1.27 cfu ml-1, respectively). The multiple pairwise comparisons test (Tukey test) of the Freundlich 1/nf parameter demonstrated a significant difference (p < .05) between the AB treatment and the RC and GB treatments. Similarly, the Kf values were significantly (p = .05) higher for the 10-g mass under the same test conditions, but no significant differences were observed in the 0.5- and 1-g masses. This study demonstrated that AB has a higher E. coli adsorption capacity and the potential for mitigating the effects of E. coli O157:H7 transport to surface or groundwater through the soil ecosystem.