A difficult fall harvest could mean an equally challenging spring planting season for soybean farmers, says Shaun Casteel, Purdue University Cooperative Extension Service soybean specialist.
Wet, cool conditions that kept some Midwest producers from finishing their corn and soybean harvests until well into November – and even December – also prevented many farmers from tilling the soil and applying postharvest fertilizers, Casteel says. That could have consequences this crop season.
"With the wet fall that we had, there were a lot of fields that were rutted by harvest equipment," he says. "We just wanted to get the crop out of the field, and so we didn't get tillage in there to break up the soil compaction that resulted from those ruts. So we're going to have some cases where we didn't get the tillage done, and producers may try to do it this spring. That's going to potentially delay planting.
"We've got nearly 70% of our bean acres in no-till anyway, and it's going to be really hard for someone to bring out a disk to fill in ruts. But I think that's probably going to be one of the best things to do if we've got some severe areas. Otherwise, we're just going to have to roll the dice and drill beans in this year and see if we can take care of any 2009 harvest compaction with tillage this fall."
Another problem that could emerge for soybeans this year is potassium deficiency, Casteel ays. Soybeans need potassium for enzyme and nutrient use, protein production and other physiological functions. Farmers often apply potassium to fields once harvest is over to give their spring soybean crop a healthy start. While most soil contains large amounts of potassium, it is often unavailable to plants.
"Most farmers I talk with say they are putting potassium out before the upcoming corn crop," Casteel says. "That's fine, but when you go back a year – to fall 2008 – fertilizer prices were really high. And so potassium, in a lot of cases, was cut or wasn't applied at all.
"Put that together with a delayed harvest in 2009, and then some of the fertility inputs that may or may not have been made, and we're going to have some potential shortcomings in our maximum yield potential in beans."
Some Indiana soybean fields in 2009 were hit with sclerotinia stem rot, commonly known as white mold. The fungal disease infects the plant at flowering and can lead to plant death. White mold infection is greatest in cool, wet weather – the kind of conditions that were common in many soybean fields last summer, Casteel says.
"White mold is environmentally driven," he says. "If a producer had problems with white mold last year, they might want to check the resistance ratings for the varieties they're planting. Some of the new varieties provided good resistance and some didn't."
Farmers also can choose new soybean varieties tolerant to Ignite herbicide, a new formulation of the former Liberty herbicide, Casteel says. The LibertyLink system is an alternative to varieties tolerant to glyphosate, the main ingredient in Roundup herbicide.
"In terms of the varieties that are available now, in looking just on the yield scale, we've got some great opportunities to yield high in our beans," Casteel says. "But just because it's a new variety doesn't mean that it's the best variety for your farm. Look at yield consistency with yield potential.
"It's worth a producer's time to do their homework and look at independent trials. In Purdue trials in 2009 alone we ranged from 6 to 12 bu. difference from the high- to the low-yielding soybean varieties. If we had $10 beans, that's a $60-120/acre management decision."
The 2008 and 2009 Purdue soybean trial reports are available online.
General information about soybean production is available on the Purdue Soybean Management Web site.