Crop ET Weekly Report

Hopefully producers won’t have to irrigate as much this year as they did in 2012, but I’d like you to consider joining a program that can not only improve your irrigation efficiency, but reduce nutrient loss and save you money!  I’ve been in Extension for nearly eight years and a program I’ve been involved with that has been a very rewarding program and made a positive impact for many is the Nebraska Agricultural Water Management Network, or NAWMN. My colleague, Gary Zoubek tracks the evaluation results and shared that in 2005 only a few producers in the Upper Big Blue NRD, (shortly followed by the Little Blue NRD) were participating, but this program has now grown to over 800 producers across the state and I’m sure we’ll add another 100 or 200 more this season!

A couple of the tools we use are ETgages® or Atmometers which mimic crop evapotranspiration or ET and Watermark soil matrix sensors which measure soil matric potential or the energy required to remove water from the soil. These two tools have really worked well and have made irrigation management much easier than those gut feelings.  The more information you have the better decisions you can make!

If you would like to participate in this dynamic program, let me know and I’d be happy to help and get you started! If you are in the NAWMN, consider installing your ETgage soon and once done with planting, start the soaking/drying cycle on your Watermark sensors to be sure they work! It’s also important to replace the #54 alfalfa canvas covers and wafers on a regular basis at the start of each season.

As I have done the past couple of years, I plan to report the weekly ET in my weekly columns. The ETgage I check is in the center of the county, just south of Geneva; hopefully it will help others become aware or have an idea what the local ET is.

The ETgage I check outside of Geneva changed 1.4 inches for the week of May 31-June 7^th. Corn in the V-4 stage has a coefficient of .18”. To calculate how much water, corn at V-4 stage used you simply multiply .18” x 1.4” for a weekly use of .25” or .04 inches/day. Corn approaching V-6 would have used .49”/week or .07” per day.

Producers with Watermark sensors, which monitor the amount of water available in the soil profile should get them installed soon. Watermark sensors are installed early in the growing season at 1’, 2’, 3’ and in some case 4’ depths!

For more information about ETgages and Watermark sensors, check out the NAWMN website.