Decide how to “ground truth” your irrigation decisions.

If you’ve ever had a broken fuel gauge in your truck, you know that whatever your method for tracking the fuel level, it will be clear when you’ve miscalculated. Messing up your irrigation scheduling will also be evident … eventually.

Make sure the data from your irrigation scheduler and the conditions in your field line up. If a significant rainfall midseason didn’t move your soil moisture estimates, something’s up.

Ease into it. If this all sounds too complicated, start slowly. There’s a lot

you can learn from using simple online irrigation scheduling tools, even if you’re not trying to use them to schedule irrigations this year. You may have a lifetime of experience growing your crop, and it’s taken you, well, a lifetime to get here. You won’t become an expert in irrigation scheduling in one day, but today is a great day to start!

Peter Robinson, PE, is a water management engineer at the West National Technology Support Center for the Natural Resources Conservation Service.

USDA NRCS crop consultant draws a soil sample. Photo credit: USDA

But when it comes to irrigation scheduling, the basic questions that have always needed to be answered are: Do we need to irrigate today, and if so, for how long?

What about surface irrigation?

According Chris Henry, PhD, PE, associate professor and water management engineer at the University of Arkansas Rice Research and Extension Center, irrigation scheduling for surface or furrow irrigation requires additional considerations:

“It is important to determine if your irrigation system is up to the task. Checking irrigation capacity is critical. It is like having a plugged fuel filter — the motor goes, but there isn’t sufficient power. Does your irrigation system have what it takes to meet the crop water demand of the crop? If not, pump maintenance may be needed, a different crop may need to be considered or deficit irrigation management will be necessary. With sprinkler and microirrigation systems, an efficient system came with the initial sale. In surface irrigation this was overlooked when the well was put down. Efficient application of water can be done in furrow and flood irrigation with computerized hole selection and surge irrigation.” 13

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