By RICK A. RICHARDS
Indiana Correspondent

WANATAH, Ind. — Farmers aren’t all that different from backyard vegetable growers. They overcome dry weather by turning on the garden hose, although for farmers, it’s a bit more complicated than turning on the spigot.

Before they can even think about watering their “garden,” farmers need to install massive irrigation systems that can cost tens of thousands of dollars to build (depending on how extensive the system is). And once it’s installed, it costs them hundreds more to maintain at peak efficiency.

Lyndon Kelley, an irrigation extension educator for Michigan State and Purdue Universities, talked about the intricacies of irrigation during a seminar, “Managing Irrigated Corn,” at the Pinney-Purdue Agricultural Center on Feb. 19.

While irrigation is common throughout the western Great Plains, where rainfall averaged only about 12 inches annually (about a third of what it is here), it’s becoming an important crop management tool in Indiana and Michigan, too.

“The difference,” said Kelley, “is that in the Western states, water rights are privately owned, making the issue a bit more complex. Here, you have plenty of water that everyone has access to.”

Of the six major corn-growing states in the Midwest, Michigan ranks first with 500,428 acres under irrigation, while Indiana is third with 397,113 acres. Illinois is second with 474,454 acres. Rounding out the top six are Wisconsin (377,291), Iowa (189,518) and Ohio (37,959).

But the need here, said Kelley, pales in comparison to Western states where Nebraska and California both irrigate more than 8 million acres; Texas irrigates more than 5 million acres.

“The need for irrigation here varies depending on the groundwater recharge in the offseason, like now,” said Kelley of the winter snow melt. “There is enough rainfall here through June that we don’t need to irrigate. After that, there often isn’t enough moisture so that we have to start using what we know about our soil profile.”

Top areas

Kelley pointed out three distinct areas where irrigation is necessary in Indiana – the northern tier of counties, and around Terre Haute and Columbus in southern Indiana.

“Those areas have sandy soil and don’t retain enough groundwater to get you through the growing season,” said Kelley. “Indiana is what is known as a supplemental irrigation state.”

Of the top 10 counties using irrigation in Indiana, nine are part of the northern tier. Only Knox County (Terre Haute) is part of that group with 30,206 acres under irrigation.

The county with the most irrigation is LaPorte (47,849 acres), following by Kosciusko (28,007), St. Joseph (25,010), LaGrange (24,723), Jasper, 22,584, Elkhart (22,028), Pulaski (19,978), Fulton (19,550) and Starke (17,299). Those 10 counties represent 65 percent of all irrigation in Indiana.

In Michigan, of its more than 500,000 under irrigation, more than 51 percent is dedicated to corn production with much of that concentrated in the southwestern corner of the state.

The key to successful irrigation, said Kelley, is making sure a uniform amount of water is put on each field. “A one inch application should be one inch everywhere in the irrigated field. That’s hard to do, but if you can get within a 10 percent deviation from the average, that’s ideal”

Kelley pointed out that farmers will have to work hard getting their irrigation equipment to work properly in order to achieve that. He said that means making sure all of the nozzles are working properly so that the amount of water being discharged at the end of the irrigation pivot is the same as the amount being discharged closest to the well. A clogged nozzle could deprive as much as 20 percent of a field of adequate water.

“If you want to apply eight inches over the season (to make up for the difference between actual rainfall and what is needed), a 30 percent deviation from one nozzle to another means you could have anywhere from as little as 5.6 inches to as much as 10.4 inches of water on your field.”

Too little water and the corn will be stunted; too much, and valuable soil nutrients can be washed away, reducing potential yields.

Paul Herrold, owner of Herrold Farms in Westville, Ind., said his goal in attending the seminar was to make sure he was irrigating his land properly.

Herrold, who will plant his 16th crop this spring, farms 2,200 acres of seed corn and soybeans just off U.S. 421 south of Westville.
“I want to see if my irrigation management practices are up to snuff,” said Herrold. “I know what I’m doing, but I want to make sure I’m doing the right thing.”

Kelley said farmers should view the soil they use as a bank for storing water. That’s why it’s key, he said, to learn how much water your soil can hold.

“That amount can vary from field to field or even from one end of the field to the other,” said Kelley. While it can be expensive to find out that information, Kelley said it’s vital for anyone considering irrigation.

“Heavier soil can hold more water per foot of depth than light soil,” he said. “Knowing how much water your soil can store can save you money. Water applied faster than the soil’s ability to store it is lost.”

Not only is the water lost, but Kelley said it’s also costly in terms of electricity to power the pump to supply the irrigation system.
Kelley said both Purdue and Michigan State have information available on their websites that provide rainfall information, how to schedule irrigation and details on farmland types.

Improve yields

Used properly, Kelley said irrigation can help crops at crucial times, like after planting or applying herbicides or pesticides. “If it doesn’t rain after an application, you might want to think about irrigation,” he said.

“Irrigation helps because it’s a timely application of water, it can help the incorporation of herbicides, improve the activation herbicides, and improve the activation and reactivation of insecticides.”

Meanwhile, Bob Nielsen, a corn specialist for the Purdue University, said irrigation is a way to improve corn yields by helping plants develop the canopy they need in order to capture the maximum amount of sunlight.

“Every decision you make potentially influences the crop canopy,” said Nielsen. Those decisions include everything from the hybrid selection to the seeding rate to row width and whether to irrigate.
“The way I look at irrigation is it is simply captured rainfall reapplied to crops,” said Nielsen. “Many of the production practices for high yielding corn under irrigation are very similar to high-yielding corn grown under adequate rainfall. Water management is what it’s all about.”

Nielsen agrees with Kelley that farmers need to know the types of soil they have and its ability to hold water. That information is vital in choosing the right kind of hybrid to plant and then knowing when and how much water is needed to produce the best crop.

None of that includes outside factors such as disease, insects, drought and temperature, but by knowing the basics, Kelley and Nielsen said it’s easier to compensate for the impact of too much or too little the factors that farmers cannot control.