Johnny Morgan, Blanchard, Tobie M., Gould, Frances I.
Examining the cultural and fertility practices involved in soybean production is one focus of research conducted by LSU AgCenter agronomist and rice specialist Dustin Harrell in Crowley.
In one study, Harrell is seeking to find the optimum planting dates for soybeans in southwest Louisiana.
During planting season, Harrell’s team plants soybeans in approximately two-week intervals, choosing the exact planting dates for days when the soil moisture is adequate but not excessive. They planted on March 29, April 10, April 25, May 17, May 29 and June 14.
“What we found in the date-of-planting study is the earliest-planted beans also were the first to be attacked by insects and disease,” Harrell said. “In past years, we’ve found that planting mid-April to mid-May produced the best yields in the southwest region.”
This year, Harrell decided to change the study a bit by adding insecticide and fungicide treatment to ensure that soybean yields are not limited at any of the planting dates by pests.
In addition to the date-of-planting study, he is also evaluating plant response to fertilization on soils limited in phosphorus, potassium and sulfur.
These fertility trials consist of potassium, phosphorus and sulphur rate and time-of-application trials, Harrell said.
“A date-of-planting study is also being conducted at the AgCenter Dean Lee Research Station in Alexandria,” he said. “All of the varieties are the same at both locations. The difference is the southwest Louisiana soybeans are drilled on flat ground instead of on beds.”
In southwest Louisiana, soybeans are normally grown in rice fields by rice producers who typically have drills and not row planters, Harrell said.
“Most growers in southwest Louisiana are not equipped to pull rows, so they use the equipment they have,” he said.
This is a disadvantage for these growers, Harrell said, because soybeans grown on raised beds tend to do better than those drilled on flat ground. An old aphorism among farmers, “Soybean don’t like wet feet (roots),” is often true, Harrell said.
The LSU AgCenter and the LSU College of Agriculture