Indiana’s INfield Advantage program has seven years of data on corn response to nitrogen rates. This year, the program adds a new project testing sulfur on soybeans.
“We will continue with our nitrogen testing on corn,” says Meg Leader, who heads up INfield Advantage for the Indiana State Department of Agriculture. “We’re adding a program to test sulfur on soybeans based on the increased yields Shaun Casteel has seen for three years.”
Casteel is the Purdue University Extension soybean agronomist. The Indiana Soybean Alliance and the Indiana Corn Marketing Council provide funds for INfield Advantage, Leader says. ISA asked the program to consider adding the sulfur trial to help Casteel gather data on responses on other soil types. Casteel helped design the protocol for the project, Leader says.
If you haven’t participated before, this would be a great time to get involved, she says.
How program works
Here is basic information about INfield Advantage, and how the sulfur for soybean project will work.
• INfield Advantage. The program seeks farmers around the state to form into groups to test various practices. Until now it’s primarily been comparing N rates for corn.
“Several groups operate around the state,” Leader says. “In each case, there is a project leader, often someone with a soil and water conservation district. It can be a crops consultant or someone else. The goal is to get local farmers to follow the same protocol for testing.”
• Imagery and sampling. Aerial imagery is collected later in the season, Leader says. One of the primary measures to compare nitrogen rates is guided stalk sampling. Staff collects samples. Lab samples are analyzed, with costs covered by the program.
• Learning and discussion. Each participant receives his or her results during the winter, Leader says. Each local group has a meeting to discuss results. Names are removed and discussion is limited to participants and project leaders.
• New sulfur for soybean project. Each grower can register one soybean field, either by June 22 in the south or July 6 in the north. The goal this year is to apply a minimum of one pass of a fertilizer applicator that is at least 1.5 times the width of the combine header, most likely with a dry source of sulfur, prior to planting.
Comparison strips are the key, Casteel says. Either apply sulfur in strips, preferably more than one, or apply sulfur over the whole field but leave strips untreated.
The preferred source for the 2018 trial is AMS at 20 pounds per acre, but other products, including gypsum, MES 10 and Sul-Po-Mag, can be used. Elemental sulfur is not recommended.
• What to expect. Two soybean tissue samples will be pulled during the season, Leader says. Aerial imagery will be gathered too. Casteel says soil tests pulled prior to fertilization and from untreated areas would be helpful. He emphasizes that yield maps are the best way to determine if soybeans respond to sulfur.
• To participate. Visit the INfield Advantage website. If you wish to work with Casteel directly, consult your local Extension ag educator.