15 Jul 2009

More Bushels for Less Water with Technology

A guest post by Brandon Hunnicutt*

It is that time of year again in Nebraska, irrigating time. The time of year that can truly make or break a crop. In a state where there is as much rain variability from the east side to west side of the state, as west coast to the east coast, water is very important. We sit on the Ogallala aquifer which serves as a great supply of groundwater for many years to come. But we want to manage it to the best of our abilities.

We have utilized different resources to help in this. We have changed many acres from flood/gravity irrigation to center pivot irrigation. We have many pivots that run only on electricity which we can have the power company interrupt during peak electrical usage time. Over the years, we have used gypsum blocks to sense when we need to irrigate. We have utilized consulting services to help determine when to start and stop irrigating. Now we are striving to go more sensor-based to determine water usage and water need of the plant.

We are using three different methods for irrigation this year. One is using Watermark sensors, which measure the amount of water in the soil. We are in our third year of using this.

The second is the AquaSpy. This one measures more points at a given time and sends the info right to my computer. Looks like something we can utilize for a long time to come.

The third piece of our puzzle is an ET gage. This helps us determine the amount of evapotranspiration for almost all our fields.

The final piece is a chart that gives an estimate of what the crop is using for water at a certain growth stage. By combining all of these resources we can get a very accurate reading of what our crop is using and when we should begin and end irrigating.

Bottom Line: The more these tools advance, the less emotion there will be in irrigating. Hopefully one day we will be able to let the crop and the soil and projected weather tell the pivot exactly when to run and when not to run. That is at least what I dream about as I am driving the 4-wheeler to check the next Watermark sensor in a field.
* A corn, popcorn, and soybean farmer in South Central Nebraska.