Precision agriculture expert John Nowatzki foresees a day — in the near future — when farmers will no longer spray pesticides across entire fields.
By combining the work of computer-controlled field spraying equipment with images collected by drones, pesticides can be applied only to areas where weeds invade crop rows.
The technology is available, said Nowatzki, but will require a shift in how people think about pesticide application. Nowatzki hopes to sell farmers on that concept with demonstrations of the latest technology and research this week at the annual Big Iron Fargo Show in West Fargo, N.D.
"The research we're focusing on is to look at just identifying the weeds and identifying where the weeds are, identifying the type of weeds and then spraying there,” said Nowatzki, a researcher at North Dakota State University in Fargo, N.D.
Nowatzki tests his drone research at an NDSU research farm 20 minutes from campus. The farm’s managers, he said, have told him that they encounter a common scenario when applying herbicides to kill weeds.
They tell him, "I'm driving up and down the field — and and most of the areas of the field have no weeds growing, but I have to spray the whole field because I don't want to miss any," Nowatzki said.
So, while the farm has the equipment it needs to focus those spraying runs, what’s missing is the data farm managers could use to tell the sprayer where weeds are, he said, so chemicals could be applied only in those spots.
Typical field sprayers, which look like a small tractor with long spray booms protruding from each side, have the technology to allow for spot applications. The sprayer might have a 180-foot-long metal arm or spray boom, but each spray nozzle on the boom is controlled by an onboard computer, allowing them to be turned on or off individually.
"[That technology is] becoming a lot more common,” said Jim Lilleberg with Fargo-based Titan Machinery. “I’d say we've seen big advancements in the last three to four years."
Among those advancements: That next-level information farmers can use to apply pesticides precisely. Images collected by a drone — or a map created by a farmer walking a field — can be processed and loaded into the sprayer’s onboard computer.
The maps can then identify specific areas with weeds or insect pests. "And I can isolate those areas, such that I only spray those areas in the field," explained Lilleberg.
In a quarter section — 160 acres of land — he said, for instance, often it’s only a fraction of a crop that needs chemical application.
"Before the technology, we would have probably sprayed the whole quarter,” Lilleberg said. “And with this technology, we can cut that back — in many cases by half, which of course is a tremendous economic impact, and also think about the environmental impact because these are after all chemicals."
John Nowatzki expects companies to offer that kind of data service to farmers in the next year, using large drones like the military flies to photograph wide swaths of farmland.
New approach makes common technology new again
Precision spraying technology isn't new, but combining it with images or other data that can zoom in close enough to identify individual weeds in a field is a still developing area.
Traditionally, a farmer would mix chemicals and water in a tank on a sprayer. Now, some field sprayers use an injection system, mixing only as much chemical solution as is needed to spray the weed-infested area.
Sprayers can also now carry several different chemicals, Lilleberg said: They can apply an herbicide where weeds are mapped and switch to an insecticide in a part of the field with an insect pest. That type of efficiency can save time — turning what might otherwise be several applications to a single one — and limits the use of chemicals, which can save money and have positive environmental impacts. But it’s not cheap.
"It's expensive technology, so it takes a while for adoption," said Lilleberg. “But from what I'm seeing, in a relatively short period of time — in the next several years — most of the operators will be adopting large portions of this technology."
The new high-tech sprayers can cost around $400,000. That's a big investment, at a time many farmers are struggling financially. That’s why Nowatzki thinks commercial pesticide applicators — companies that farmers hire to spray their crops — are more aggressively using the new technology. But chemicals are a big part of the cost for growing crops, so eliminating some of that cost could increase a farmer’s profitability, Nowatzki said.
In addition to helping survey the land to be sprayed, drones are also playing a role in the actual application of some chemicals. NDSU researchers are using a small drone equipped with an 8-foot spray boom to apply chemicals to small portions of fields. They’re testing the approach as an even more precise companion to the giant, computer-driven field sprayers.
"This drone is not going to replace the big field sprayers. These farmers are running [a] 180-, 200-foot boom,” said technician Sheldon Tuscherer. “This sprayer is not meant to replace that. This is meant for just precision application."
Carrying 4 gallons of spray in a tank, the drone can only fly 25 minutes before needing fresh batteries. But Tuscherer said it's efficient for small applications.
"You can fly the drone down a fence line, if it's full of weeds, rock piles — there's always weeds around rock piles," he said.
Farmers attending the Big Iron Farm Show in West Fargo this week can watch demonstrations of the latest spray technology.