Daily Crop “ET’s” at Their Peak

Jerry Wright, Extension Engineer, University of MN

Daily water usage for most crops is at its full potential (0.15 to 0.3 inches per day depending on temperature and cloud cover). This will continue for at least the next 4 to 7 weeks. Keeping track of daily crop water usage (ET) for the past 2 to 5 days can greatly assist an irrigation manager in deciding when to startup the next irrigation.

For most crops in full canopy and flowering, it is generally best to start irrigating when the soil water in the rooting zone has depleted 1/2 to 3/4 inches of water depending on the crop’s rooting depth and the water holding capacity of the soil.

Past day’s estimated crop ET potential across the state of Minnesota and Wisconsin can be viewed via a color coded map available on the internet at the following address: http://www.soils.wisc.edu/wimnext/

Regular in-field soil moisture checking and keeping track of a crop’s daily ET use can go a long way in helping an operator optimize the crop’s growth while reducing the potential for leaching of some crop inputs like nitrogen into the groundwater.

Additional information on how to use daily crop ET information can be obtained from Jerry Wright, Extension Engineer at the West Central Research and Outreach Center in Morris, MN at (320) 589-1711 or jwright@.umn.edu.

Co-Editors: Bill Hutchison, Department of Entomology, University of Minnesota, hutch002@tc.umn.edu
Jeanne Ciborowski, IPM Program, Minnesota Department of Agriculture, jeanne.ciborowski@state.mn.us
Cindy Tong, Department of Horticulture, University of Minnesota, ctong@extension.umn.edu
Production Editor: Suzanne Wold, Research Specialist, University of Minnesota, woldx018@tc.umn.edu

Disclaimer
Reference to products in this publication is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in this publication assumes full responsibility for their use in accordance with current directions of the manufacturer

Last Revised July 13, 2000.
The University, including the Minnesota Extension Service, is an equal opportunity educator and employer.©1999 Minnesota Extension Service, University of Minnesota. All rights reserved. Contact copyright@extension.umn.edu for information on reproduction or use of this material.