Responsible water use is an important component of today's agriculture. And if you irrigate, you must do your part to make sure your irrigation program is the most efficient it can be.
Scheduling: There are several software programs available that help schedule irrigation passes. You input your maturity, planting date, temperatures and rainfall. The program then tells you when to irrigate. You can also use tensiometers which measure the water in the soil. Remote weather stations are also becoming economical, and the data can be feed back to your PC or smart phone. Personally, I tend to go old school. I use the checkbook method. Normally, we get a rain that saturates the soil sometime in the early summer. I mark that date on the calendar, and go from there. I keep track of the growth stage of the crops, and calculate the usage. When the soil reserve draws down to less than 50%, I will begin to turn irrigation on.
Efficiency: A few years ago, we had the opportunity to upgrade some of our older systems through the EQIP program. We changed from impact sprinklers on top of the pipe to rotators or iwobs on drops. This change puts the application closer to or in the canopy, which reduces the evaporation. We also changed some of the wells to be lower pressure, as the demands of modern systems require less pressure. These lower pressure pumps require less power and help save on the electric bill. I would encourage everybody to check with the NRCS about EQIP programs.
Multitask: We are going back and doing trials on fertigation and chemigation of irrigated fields. Dad did this in the early 80's, but we got away from it. In our second year back, we are realizing this again adds a layer of management. However, data we've seen has indicated this work will pay dividends. Based on soil and tissue test, the wet early summer season took a toll on soil nutrients. I can confirm we had some leaching. Nutrients need to be replaced for top yields this fall. I will be disappointed if we don't see a good response this fall.