8/17/2013 7:00 AM
By Ann Wilmer Maryland Correspondent
DENTON, Md. — More than 300 farmers, students and others who work in agriculture gathered to hear a series of presentations on precision agriculture at Caroline County 4-H Park near Denton, Md., Aug. 7.
The annual event is hosted by the University of Maryland Extension Service in cooperation with Virginia Tech and the University of Delaware Cooperative Extension Service. Major underwriters included Atlantic Tractor LLC, DuPont Pioneer, Farm Credit, Hoober Inc. and Willard Agri-Service.
Farmers flocked to the event to learn about technological developments that can help them farm more efficiently as well as earn nutrient management credits.
Greg McCabe, a grain farmer from Selbyville, Del., who plants corn, soybeans and wheat, said he attends these presentations to keep up on the technology side. Another young farmer from Henderson, Md., too shy to share his name, said he was looking to upgrade his entry-level GPS system because even though he sees the advantages, he’s not sure it is accurate enough to meet his needs.
Like others in attendance, these two producers were interested in hearing what the presenters had to share.
Randy Taylor from the University of Oklahoma, is a researcher who doesn’t mind getting his hands dirty out in the cornfield. He has been crunching the numbers from field tests of seed meters in his state. His team tested three different seed meters at four planting speeds and assessed the results by counting the plants that came up.
“Improved metering doesn’t eliminate all seed spacing errors,” Taylor said.
What researchers learn from the tests will provide some guidance for future planting. For example, they learned that the optimum speed for planting was 5 mph. They also found that the speed also affects vibration, which exerts a down force.
Taylor explained that a vacuum system adjusts the rotational rate of the meter, giving the user control over the rate at which the seeds are drilled into the ground. This rate varied by location.
The standard deviation of the number of seeds down the tube and into the ground can be compared with results to indicate seed bounce.
They tested three kinds of meters: standard corn, ProMAX 40 and eSet. The tests also included five metering speeds ranging from 300 seeds per minute to 1,500 seeds per minute. Results showed that the variability in exit point was greater for a standard disc than for either of the other meters tested.
Wear and tear on seed tubes also increases variability, said Taylor, making equipment maintenance critically important for best results.
Another important variable that can be controlled by using a seed meter is the number of seeds drilled when making a turn. By shutting down some of the seed tubes, the number of seeds planted in the inside of a turn can be reduced to make the seeding rate more uniform overall. The wider the boom, he said, the more significant this is in terms of reducing seed waste and harvest results later on.
The results don’t provide a “one-size-fits-all” formula. Taylor said questions still remain and results vary from farm to farm.
“What is the optimum seeding rate in your most productive ground? What is the difference in the seeding rate in your least productive ground?” Taylor said.
The bad news is that farmers can’t rely on Extension agents to tell them what seed rates and fertilizer application rates to use for peak production.
“What the state Extension service can tell you is the average. And averages are just that,” he said, adding that farmers will still have to do some research on their own to figure out what works best on their own fields.
Taylor also presented some additional research gained by hand planting. Although hand planting is not practical for serious grain farming, the results of research plots created and maintained by Oklahoma State graduate students offer a new challenge to mechanical seed drillers. He said researchers have found that when all the seeds are similarly oriented, leaf orientation is also similar. This produces 10 percent greater yields on average in uniformly oriented stands.
When the plants are aligned, they make more efficient use of sunlight.
“Farmers are in the solar energy business,” he said. “We collect sun, combine it with water and try to make money.”
To achieve uniform orientation as well as spacing requires absolute accuracy. Machines are still not capable of perfect placement; there are just too many variables.
“So the question is, how much deviation is tolerable?” he said.
Researchers are now looking at accuracy in terms of getting a substantial, if not optimum, benefit.
So far, Taylor said the most promising results have come from using flat seeds. Still, the relative velocity between the seed and the ground is a real challenge. Closing the wheel can also change the position of the seed.
Taylor said the focus of planter performance should be toward establishing correct seeding rates in subsequent plant stands and as close to absolute spacing as possible. He said the easiest way to achieve that is to begin a proper maintenance operation and to make adjustments as needed.
Although it will probably be a while before mechanical planting equipment can control seed orientation as well as uniform spacing, Taylor said it suggests what farmers might expect down the line.
Other presentations during the day included zone management for row crops and demonstrations of a number of available technologies for data collection, mapping farm acreage, application of nutrients and pesticides and farm management.
Farmers unable to attend the event can view the presentations online via the website, www.enst.umd.edu/Extension/Prec_Ag.