“We don’t have the on-farm total average because some of my corn is still in the bin, and I don’t have my weight tickets for the unsold corn yet, but it’ll be somewhere between 320 and 330 bushels for the whole farm, and that particular farm is 100 acres. On that farm we harvested only 91 irrigated acres.”

In addition to growing his own corn, Dowdy consulted on between 2,500 to 3,000 acres of corn production this year in Georgia and north Florida.

“All these guys had very good yields. Although it was a dry year, we were actually fortunate to have cloudless days. This promoted cooler nighttime temperatures, and the plant was able to ‘rest’ at night.  Also, the lack of cloud cover enabled maximum photosynthesis to occur during the day which was an advantage as long as you had irrigation. I irrigated 26 inches this year compared to 9 inches last year.”

Dowdy had an eight to nine-week period during which he didn’t see any rain.

“The corn pollinated at from 96 to 104 degrees F. I tried some new irrigation techniques this year that worked. The key is to keep the plant as cool as possible during the high temperatures of the day and at night.

“One of the biggest mistakes I feel farmers make is that when their land is irrigated and they get rainfall, then they think the corn should have enough water. You have to know your corn has enough water. You can’t make high corn yields unless you can supply the plant’s water needs. If you get rainfall, then that’s a bonus.

“At best, you may be able to eliminate an irrigation trip, but only for the amount of that rainfall. If you don’t have a pivot that can put out four to five-tenths inch per day to keep up with plant needs in conjunction with the evapotranspiration rates, then your water profile will continuously decrease, because you’re losing at least a half inch of water per day from around 60 to 110 days after planting.”

If water is limited, he says, this issue alone should influence you to plant half a pivot instead of a whole field or plant on fields with small pivots. When a farmer is doing his planning, the most important thing he can do is make sure water is not a limiting factor, says Dowdy.

He uses the University of Georgia’s irrigation table as a guide but not a rule. “It tells you the plant water needs in relation to days after planting and growth stages. It is necessary to be aware of your soil types and have intimate knowledge of your soils’ moisture holding capacity.

“This is the easiest way of estimating the amount of available water for the plant and promoting timely scheduling of irrigation.  They call it the checkbook method.  I’m considering incorporating soil moisture probes for this next year because it might help me eliminate some watering.”

Some of Dowdy’s fields have been in continuous corn for five years, and he doesn’t agree that you’ll always see a yield reduction in corn following corn.  He has been double-cropping a legume behind the corn to help with weed control and to help fixate some nitrogen. 

“You will see a yield reduction if you don’t perform certain practices. You need to perform deep tillage in the fall, plant a cover crop, and apply some nitrogen after the corn is harvested. This is done so the soil microbes can feed off the nitrogen and begin to break down the corn fodder and remove some of the disease and insect risks associated with heavy corn residue.