Water Sampling of Irrigation Ditch (image) American Society of Agronomy Share Print E-Mail Caption A University of Arizona graduate student collects a water sample from an irrigation system. Credit Natalie Brassill, University of Arizona. Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.