Availability of improved soybean varieties, combined with good management of water, insects, weeds and disease make soybeans a key link in Southern crop rotations. Thousands of Southern growers see the advantages of having soybeans as part of their corn and rice rotations. One of those farmers is Jason Waller of Mer Rouge, La. Several years back, he had excellent luck with beans double-cropped with wheat and rotated with cotton.
“With the high prices we’ve seen for soybeans, we are concentrated more on full-season beans,” he says. “We’ve had good luck with ‘wheat beans’ but feel we can see more return for regular soybeans.”
Waller’s crop rotation is combined with furrow irrigation. He uses polypipe to run water on the blend of sandy and clay loam soil that has a reputation for solid yields. He has used either a two years rice/one year soybeans rotation, or beans rotated with corn.
Mississippi State University soybean specialists say earlier maturing varieties like Group IVs have allowed southern growers to increase yields by avoiding late summer weather patterns that are typically hot and dry. Waller plants Group IVs.
His corn program also works into his soybean plan. It takes advantage of residual nitrogen remaining from beans that helps hold back weeds that can create problems.
“We plant 100 percent GENUITY Roundup Ready 2 Yield soybeans and tank mix multiple modes of action with our glyphosate herbicide,” he says. “That provides good control of resistant marestail in corn and soybeans. We have escaped any pigweed resistance problems due to our corn herbicide program of applying atrazine.”
Southern insect control in soybeans normally involves three to four sprayings of pyrethroid insecticides to control stink bugs, earworms and other critters.
However, 2012 was an exceptional year — for the better — in parts of the South. “We didn’t have to spray for any insects through mid-August,” Waller says. “Some area growers had to spray one, maybe two times. But it was a very light year for insects. We can’t count on that for every year, though, so we always budget for insect control.”
Soybean specialists across the South encourage farmers to take care in guarding against disease.
Louisiana State University soybean specialists note that different varieties of soybeans differ in susceptibility to diseases and nematodes. For example, aerial blight is an important disease south of Alexandria in central Louisiana, but it can also spread into other parishes or counties during wet seasons.
Stem canker has become a serious disease, but is erratic from year to year, LSU says. Another disease of increasing importance is cercospora. These late-season diseases cause yield losses and harvest delays.
Phytophthora root rot disease is more prevalent in clay or poorly drained soils, and root knot nematodes are more prevalent in sandy soils. LSU notes that cyst nematodes may occur on all soils. When these diseases occur, results can be devastating, so variety selection is very important, LSU says.
“We also work fungicides into our budgets early in the year,” Waller says. “There can always be a threat of Asian soybean rust, and there are additional diseases that can hurt bean yields. We use treated seed and make fungicide applications in plenty of time to ward off any disease infestations.”
His soybean yields are about 50 bushels per acre, “But we’re seeing what could be a 15 percent to 20 percent better yield in 2012,” he says. “It is proving to be a good year.”
He partially credits his improved yields to switching to twin-row planting. His regular rotation has been with 38-inch rows. With the twin rows, he plants on 38-inch centers, with rows 8 inches apart.
“I’m seeing some advantages to twin-row, not only with yields, but with weed control,” he says. “We can get by with one less herbicide application. Once the middles are locked up, we see better moisture control; water stays in the fields longer.”
LSU says lodging can be a problem in soybeans and is more likely to occur with a population of more than 6 plants per foot of row on highly fertile soil. Tall varieties tend to lodge more severely than short ones, LSU says. A lodged field is more susceptible to disease and reduces harvest efficiency.
Seed treatments should be considered, say Mississippi State University soybean specialists, particularly on poorly drained soils or on soils with a history of seedling disease.
They recommend seed treatments under five scenarios: planting under cool, wet conditions; planting into heavy vegetation; planting late when it is hot; planting seed of less than 80 percent germination; and if there is a history of seedling disease. “If you continue to plant early, it will be rare if you avoid cool, wet conditions,” the MSU specialists say.
Waller says seed treatments, as well as an all-around soybean management program, are vital if strong yields of quality beans are expected. He uses extensive on-farm storage to hold soybeans and other crops until markets provide the best prices.
“You really have to be a good marketer and a good manager, especially with your water,” he says. “If you do that, you should make a good crop and a sound return on your land,” he says.