You've experienced it before. It's time to plant soybeans, and the weather isn't cooperating. Fields are too wet, and time is slipping away.
But Lanny Ashlock, a University of Arkansas soybean specialist, has come up with what seems to be a viable solution to the problem on clay soils.
"We wanted to try aerial planting with soybeans for a long time, and in 1997 we finally did it," he says.
Ashlock is working with Larry Earnest, superintendent at the university's Southeast Research and Extension Center, Rohwar. They seeded early Group IV soybean varieties in April that year, when it was too wet to plant with ground equipment. The plane needed no modification; existing fertilizer hoppers were used for the soybean seed.
"The airplane was at 100' going 125 miles per hour - the seed was partially to completely buried in the soil on impact," says Ashlock.
Soil conditions must be right - wet but not too wet. Ashlock and Earnest kept the field flooded over winter to maximize soil moisture and minimize winter weeds. They drained it about 36 hours before planting and applied Roundup to kill dock on some high spots that had dried out when the flood was accidentally lost.
For additional surface control, a grid of drain furrows was established to quickly drain water when necessary.
The beans averaged 25 bu/acre on marginal land without irrigation. Some parts of the field yielded 40 bu/acre, Ashlock reports.
Last year, the two scientists aerially seeded 50 acres of beans on irrigated land. The aerial seeding cost ran about $6/acre, and seeding rates were increased by 10 lbs/acre.
"We applied 70 lbs/acre as opposed to 60 for a conventional drill, but it only took a few minutes of flying time to plant the 50-acre field," says Earnest.
An early Group IV variety yielded about 48 bu/acre; a late Group IV, in the low 50s.
"We were very pleased and are going to try to enlarge that acreage to 150 this year," Ashlock reports. "I think this technique has real promise for clay fields."
However, he hesitates to recommend it for other soil types.
"The soil needs to be plastic enough so that, when the seed drops from the plane, it almost embeds itself in the soil," he says. "On sands and silt-loam soils, the seed hits and barely sticks to the ground. The soil is rather firm, even when it's wet."
Best results are likely when aerial seeding is done, not as an emergency operation, but as a planned practice, says Ashlock. Land preparation, which includes leveling and establishing levies and drain-furrows, must be done before winter flood.
"Quite a bit of thought needs to go into it in the fall," he says.