When Larry Gingrich's county agent asked him to participate in a precision farming experiment with alfalfa, he jumped at the chance.
“We grow only alfalfa,” says the 150-cow dairy farmer from Leroy, MI. “We want to grow it well.”
Gingrich was motivated by economic and environmental concerns. His farm is up slope from pristine Rose Lake, where waterfront lots sell for $75,000. Gingrich was Michigan's Conservation Farmer of the Year in 1998 because of what he's doing to protect the lake from nutrients and sediment.
Like most alfalfa growers, Gingrich noticed variability in yields and quality within his fields.
“We have high spots and low spots, and we don't know why,” he says.
Grid soil samples showed soil pH ranging from 5.9 to 7.3, potassium levels ranging from 90 to 470 lbs/acre and potato leafhopper and alfalfa weevil damage moving and shifting with no clear patterns. First-cutting yields varied by almost 2 tons of dry matter per acre, according to the swather-mounted yield monitor.
Alfalfa fields on three farms, including Gingrich's, are under intense scrutiny in a study by Michigan State University forage agronomist Rich Leep. Points are staked in a grid pattern and their locations recorded using a differentially corrected global positioning system. Topography maps were created. Soil samples were taken and analyzed. Yields are recorded using hand yield checks, yield monitors mounted on cutting equipment, and near-infrared reflectance (NIR) data taken using backpack units and aerial and satellite photography. Insects are monitored weekly using sweep nets.
One goal is to correlate technologies.
“We've found that NIR readings from aerial photography do a remarkably good job of estimating crop vigor,” says Leep. “We have the actual hand-collected yield data to compare.
“The yield monitor on the harvester is also accurate. The problem has been keeping the computer and the hardware working in field conditions that include dust, vibrations and temperature extremes.”
Even with yield monitor difficulties, results so far are intriguing.
“Both the NIR aerial photography and the harvester-mounted yield monitor found things that grid sampling even at the ¼-acre level didn't pick up,” Leep says.
On one set of aerial photos, high- and low-yield strips appeared. Records showed the alfalfa had been planted over corn and alfalfa conservation strips.
“This indicates a probable auto-toxic effect of alfalfa being planted after alfalfa,” says Leep.
The NIR aerial photography also clearly showed areas where wheel traffic compacted soil and damaged plant crowns.
Potato leafhopper populations are mobile and vary greatly across fields.
“We need to evaluate new control strategies for leafhoppers,” says Leep. “It may be possible to spray specific zones of the field rather than the entire field.”
Gingrich hopes this effort will elevate his alfalfa management to a new level.
“We quit growing corn,” he says. “Farmers farther south grow it better and cheaper, and we didn't need all that tillage on our erosive land.”
He has learned how to make good use of no-till and annual forages between alfalfa stands. “Now our land is never really open.”
Economics dictate good management at Gingrich Meadows. Three families make their living there. Larry and Elaine's son and daughter-in-law, Shawn and Michelle, and daughter and son-in-law, Amy and Craig Martin, are all involved.
Getting the right alfalfa yield for the right amount of inputs, with no nutrients or soil leaving the farm, is the goal.
Diverter Creates Touching Windrows
A homemade swather attachment helps Gingrich Meadows save a field trip when alfalfa is cut for silage.
It's a windrow diverter, a mechanism that fits under the cutting machine. It has a 4'-wide belt, operated by hydraulic motor, which catches hay as it comes from the conditioner rolls and moves it off to one side. Cutting up the field and back results in two windrows lying side by side, just touching.
A hydraulic arm positions a board that stops the hay from flying too far off the belt. That's needed for the windrow dropped beside the standing hay.
“When the hay isn't too heavy, the chopper will handle 32' of it at a time,” says Larry Gingrich. “Instead of raking two 16' swaths together, we lay them side by side in windrows.”