Favorable weather would be welcome news for farmers wanting to plant their corn and soybean crops.
Persistent moisture, which has included a deluge of rain in some areas as well as colder than normal temperatures, reduced preparation time.
In Kansas, corn planting was at 46 percent, behind the 65 percent in 2018, and well behind the 67 percent average, according to the Northern Plains Division of the National Agricultural Statistics Service. Soybeans planted was 7 percent, well behind 28 percent last year, and behind the 16 percent average.
Nationwide, the USDA estimated earlier this year about 92.8 million acres of corn were projected to be planted this spring and about 84.6 million acres of soybeans.
On May 7, agronomists from the University of Missouri Extension reported from “no corn in the ground at all” to 40 percent planted. Regional agronomists expressed concern about uneven emergence of corn in fields already planted.
Yield loss can happen when smaller plants compete for nutrients and sunlight with larger, earlier-emerging plants. Smaller plants will likely produce barren or small ears.
Seeds that emerge 10 days behind their row mates lessen in-row yield potential. Studies vary, but agronomists in Wisconsin and Illinois estimated losses at 8 to 10 percent in older research, says MU Extension corn specialist Greg Luce.
Growers cannot change the calendar or predict the weather but in terms of corn production, Tim Laatsch, a technical agronomy manager with Koch Agronomic Services in southern Illinois, suggests they focus on optimal planting date, citing a long-term University of Illinois study that determined the optimal planting date for corn in the central Corn Belt normally occurs from mid-April through the first week of May.
“As you push back that planting date and you reach May 10 you see a 5 percent yield penalty and you start accumulating a half percent yield penalty for every day you plant after May 10 through May 30,” Laatsch said. “Most farmers are aware of that yield penalty for delayed planting so one of the biggest considerations is to be able to plant timely. They may have to adjust some of their plans with respect to nitrogen management of that crop.”
Numbers remain relevant, Luce says, even though improved precision-planting equipment reduces irregularities. Skips and smaller plants are still likely. “Skips are what you don’t want,” he says. “Doubles are a planter issue and certainly not desired, but they don’t have the negative impact on yield like a skip.”
Luce says uneven emergence happens for several reasons: Soil crusting, compaction, inconsistent and especially shallow seeding depth, and differences in soil temperature. Seed-to-soil contact matters as well. This year, cool weather provided fewer growing degree units, which are needed for corn to develop strong root systems and emerge uniformly.
Laatsch said farmers affected by floodwaters or wet conditions need to develop contingency plans, which include communicating with their core retailers.
Contingency planning is necessary because this spring follows one of the wettest falls in 2018 and most limited anhydrous ammonia application season on record, he said. March and April saw limited fieldwork and, as a result, that will put stress on the infrastructure system to get all the nitrogen applied for this season.
If the producer opts to plant first to meet a desired planting date, the Illinois study also indicates that waiting too long to apply nitrogen will likely mean a yield penalty, too, Laatsch said.
“If you wait until after planting, I would encourage growers and retailers to consider applying two-thirds as early as possible say right around corn emergence or in the early vegetative stages as soon as you have an chance to evaluate the stand and make any kind of replant decisions. Get that first sizable majority shot of nitrogen on the crop.”
He encouraged growers to consider making the other third of the application of nitrogen around the mid-vegetation V-5 to V-7 growth stage.
“Waiting much longer you take too much of a risk the nitrogen will never make it in the plant,” he said. “We want to make sure there is an ample supply of soil nitrate available to that growing corn crop as it accelerates into that vegetative growth stage and starts to take up a large quantity of nitrogen.”
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He also advises growers to consult with their seed dealers to check with maturity dates to see if they might have some additional flexibility. Phosphorus and potassium fertilizer should be readily available.
“Nitrogen is the most likely input to shift because of the sources available and options to stabilize,” he said. “Make sure you are communicating with your retailers on your options.”
Producers may look to plant soybeans if the corn-planting window closes but that will be a localized decision, Laatsch said.
High water issues
Mike Riffle, with MycoApply, a division of Valent U.S.A., said if the waters stay on top of the ground for an extended period of time, they can cause severe damage to soil health. In April, he noted flooded soil syndrome in eastern Nebraska and western Iowa as a result of flooded conditions that occurred about two months ago. At that time there were fields that had flooded for quite a long time, a month in some cases.
With extended flooding biological, chemical and physical problems can happen in the soil.
“Under heavy water, flooding conditions there is an anaerobic condition so you have a lack of oxygen to begin with and you are messing up the soil microflora and that’s where all the soil organisms live,” Riffle said. “All kinds of things that live in the soil that are severely impacted when you have a flood. If it stays that way for a long time the growers know they have to deal with what happens after the flood recedes.”
Growers also have the challenge of physical damage that can be extensive from sedimentation, which can include sand. Other new hazards can include large gullies, trees and debris removal before planting can start, Riffle said.
Laatsch and Riffle both said producers should consider investing in a soil test. Laatsch said farmers might need to consider a nitrification inhibitor, such as Centuro, to assist them as they may have to weigh when to apply nitrogen.
“A producer may have to defer some or all of it until after he plants,” he said. “One of the biggest concerns is rushing into field conditions that are too wet and setting yourself up with compaction and restricted root zones that can really cap your potential later and, secondly, going out in too wet of conditions and having improperly sealed injection plots that may lead to direct losses of ammonia gas.”
Riffle said producers can use a supplement such as MycoApply EndoPrime SC, a new product with four species of mycorrhizae, which will help restore the soil structure and aid in nutrient update for the crop.
A wetter and cooler May has many Oklahoma cotton growers reaching for their soil thermometers before hitting the fields. With seed availability already at critical lows, it’s vital that growers plant the seed they have been able to source in as optimum environment as possible because replanting may not be an option.
In the May 9 “Cotton Comments” newsletter from the Oklahoma State University Southwest Oklahoma Research and Extension Center, Extension Assistant Jerry Goodson wrote that “cooler than normal and saturated fields have prevented the start of planting this year.”
The Oklahoma Mesonet shows that 4-inch bare soil temperatures across the state range from 50 degrees in the panhandle, to 67 degrees in the far southeast corner as of May 9. The next seven days weather forecast calls for lows ranging from 38 to 60 degrees, and highs from 51 to 77 degrees. And, just about every day has a chance of rain and thunderstorms in the forecast, according to the newsletter.
Already, across much of Oklahoma, the last two weeks have accumulated up to 6.97 inches of rain in the southwest corner, to 9.77 inches of rain in the far northeast corner of the state, according to the Mesonet, further delaying planters getting into the field.
“The optimum temperature for cotton germination is near 85 degrees,” Goodson wrote. “Cooler temperatures can lead to poor stands or stand failures if the correct conditions align.” Slow germination because of the cold can lead to slow growth, which adds time that the cotton seedling is susceptible to disease pathogens.
Goodson advised growers to:
Delay planting until mid-morning temperatures in the rooting zone are higher than 60 degrees at a 6-inch planting depth, and 68 degrees at the 2-inch planting depth;
Wait until the Mesonet’s 5-day forecast calls for dry conditions and at least 25 DD60 heat units; and
Wait until that same five-day forecast calls for lows above 50 degrees.
For more information, visit www.cotton.okstate.edu or call 580-482-8880.