Precision agriculture is anything that helps grow crops more efficiently. LSU AgCenter researchers have continued to research precision ag technology like drones and sensors to help farmers gather more accurate crop and field information. This can give farmers more control over their fields.
“The deal for precision ag is to save more money, be more profitable and think about the long term,” said Luciano Shiratsuchi, a precision agriculture specialist with the LSU AgCenter.
One ongoing precision ag project has been comparing soybean, corn and wheat varieties on variable soils. Most of the statewide core plot trials are being done on-farm to better account for typical soil variability and to, ultimately, add more data to existing variety trials.
“We use imagery and soil sensors to support better strategy in selecting varieties,” Shiratsuchi said. “If you use a drone to map the soil, you can differentiate and make zones that make it fairer when making variety comparisons. The maps can also help determine where to put trials to minimize any biases.”
Electrical conductivity sensors are used to measure several soil fertility parameters, such as organic matter, potassium and texture.
In a core plot trial, researchers assisted farmers in planting a standard variety with other varieties or hybrids close to it and in a particular zone. Three different soil fertility zones exist: high, medium and low.
The hybrid corn tests have an additional focus to determine plant populations and how many seeds should be planted per acre. Varieties were planted on rows next to the standard one at different seeding rates.
Over the last few years, data sets collected from 56 sites showed the best average rate for soybeans was 140,000 seeds per acre. But it is not necessarily a one-size-fits-all formula, according to Shiratsuchi.
“If you put too few or too many seeds you can hurt the yield and profit,” he said. “We are trying to determine guidelines for proper plant population, which will maximize yield.”
On the farm level, AgCenter researchers are trying to determine the best number of seeds per acre, based upon a particular zone, when using variable rate map technology.
“This can help determine a good strategy to do variable rate seeding,” he added.
Shiratsuchi’s research team is also creating a web database for farmers to access important data and make queries across regions and varieties.
The Dean Lee Research and Extension Center near Alexandria is the site of another precision ag project. Researchers have been looking at ways to identify the overall plant health and biomass of soybean, oat and wheat crops using alternatives to expensive NIR (near-infrared) multispectral drone cameras.
“We’ve tested lower-priced, retail store drones that use RGB — red, green and blue — cameras and had, in some cases, slightly better results than with NIR cameras when compared to the GreenSeeker technology,” said LSU AgCenter engineer Randy Price.
Another test application for the RGB cameras was attempting to indicate disease severity in oats, wheat and corn.
“It looks very promising as a disease indicator, but we need data for more years,” Price said. “We’re working on quantifying data, but if it’s successful, you may be able to rate disease severity with a drone and then precisely spray with a sprayer drone.”
Other drone research at Dean Lee has been investigating the use of agricultural sprayer drones for more precise spraying treatment applications.
“It looks like drone spraying will have a lot of promise for farmers in Louisiana,” Price said.
The drone applies spray from at least 10 feet, potentially making it more effective to the plants. It also has a downdraft that might be good in moving applications down into the plant canopies, according to Price.
Price doesn’t think these big drones will replace airplanes because airplanes can spray many acres quickly. They also would not replace trucks because they are an economical way to spray when it’s dry.
“But I think there’s a niche for these big drones for smaller acreage, particularly where there are wet spots or spots with trees,” Price said.