The weather's taken a major turn for the better since the slow, cool, wet start to the planting and growing season earlier this spring. But, there are still pockets -- like parts of Indiana -- where the weather's not been consistently great, especially for farmers still working to get their soybean crops planted. As a result, one expert's recommending some changes to your soybean management in these early phases of the growing season -- namely during planting -- to get that crop started out right.
"Just like any good roller coaster, the rise of temperatures peaked so it could plummet downward while the intensity and frequency of rain skyrocketed. All this occurred in our typically prime planting weeks," Purdue University Extension soybean specialist Shaun Casteel says of the weather that's been drastically inconsistent since farmers started spring planting. "We need to set the stage for the best possible return on late plantings."
As of Sunday, 87% of the nation's soybeans were planted, up 9% from the last week, but the last few acres left to plant may take a while in some areas because of the frequency and amount of rain that continues to fall, Casteel says. With that being the case, he recommends the following considerations if you think your soybean-planting window might stretch well beyond normal, according to a Purdue University Extension report:
Seeding rate: Planting in the first half of June requires increasing seeding rates 10% to 20% to foster quicker row closure and higher pod height with fewer days to flowering. Increased seeding rates will also be needed in those fields that have heavy corn residue, which has been prevalent this planting season because of limited breakdown over the winter.
Farmers who typically plant 140,000 seeds per acre in 15-inch rows should increase the rate to about 170,000 seeds per acre in the second week of June; 185,000 in the third week; and 200,000 in the fourth week. Soybeans will produce fewer main-stem nodes (attachment points of trifoliates and ultimately pods) as planting is delayed, so the increased seeding rates will also help to overcome the shortage in node production.
Row width: Farmers planting 30-inch rows should consider planting narrower rows with the limited time to flowering. Soybeans typically have a yield advantage of 5% to 10% for soybeans planted in narrow rows (15 inches or less) compared with wide, 30-inch rows.
"This difference will be even more prominent in late-planting situations," Casteel says. Wide rows take nearly 25 days longer to canopy compared with 15-inch rows and 40 days longer than 7.5-inch rows.
Maturity group: Full-season varieties should be planted until June 15 for the northern quarter of the state, June 20 for the central half and June 25 for the southern quarter. Varieties should be dropped by one-half maturity group from the full-season variety for the area, such as from 3.5 to 3.0, after those dates and planted for another two weeks before farmers consider other alternatives. The lower the maturity group the faster the plant will develop flowers, pods and seeds.
"If you are in a very late planting situation, I suggest back-dating 90 days from the typical fall freeze in your region to determine if you have enough growing season to mature a soybean crop," Casteel says in a university report. "My hope is that you will not need to make that determination."
