Does pasture irrigation increase groundwater contamination?

Does pasture irrigation increase groundwater contamination?
This image shows dairy cows grazing next to a stationary Center Pivot irrigator. Credit: Murray Close.

Concern about microbial contamination of groundwater from foraging dairy cows has increased as spray irrigation practices in New Zealand have increased over the years. Bacteria capable of living in both animals and humans are commonly found in cow manure. Addressing the lack of research on the topic, a team of New Zealand researchers studied the transport of microbes from two spray irrigated dairy pastures into groundwater supplies.

The research team, reporting in the May-June 2010 and published by the American Society of Agronomy, Crop Science Society of America, and Science Society of America, found little to no transport of microbes due to spray irrigation application.

When irrigation applications were increased to simulate irrigation plus heavy rainfall, there was a small increase some forms of bacteria, notably E. coli. But other common bacteria were only detected at very low levels when fresh cow pats where subjected to this treatment.

The results of the study indicate a minimal impact of dairy farm pastures on microbial quality of as a result of spray irrigation.

Previous studies of flood irrigation, which apply much more water less efficiently than the spray irrigation systems used in this study, have been shown to cause high levels of groundwater contamination. No difference was noticed between two different spray irrigation systems, a traveling irrigator and center pivot. The researchers suggest that converting from flood irrigation to spray irrigation will reduce microbial contamination f groundwater and reduce environmental health risks.


Explore further

Sinus problems are treated well with safe, inexpensive treatment

More information: View the abstract at jeq.scijournals.org/cgi/content/abstract/39/3/824
Provided by American Society of Agronomy
Citation: Does pasture irrigation increase groundwater contamination? (2010, June 14) retrieved 18 June 2019 from https://phys.org/news/2010-06-pasture-irrigation-groundwater-contamination.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more