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Corn and nitrogen as rain continues

Published June 26, 2015

URBANA, Ill. - Rain has fallen in Illinois nearly every day for the past three or four weeks, and rainfall totals for this period are two to three times above normal for more than half of the state. This has a lot of people wondering if enough nitrogen remains in the soil to supply the corn crop, said a University of Illinois crop scientist.

Daily high temperatures have averaged close to normal over the past three weeks whereas night temperatures have been 3 to 4 degrees above normal, so growing degree accumulation rates remain high, said Emerson Nafziger. “Sunshine amounts have been marginal, but growing conditions have been good enough to keep the crop coming along rapidly,” he added.

Fields that were planted in April in central Illinois are rapidly approaching tasseling, Nafziger noted. “With warm temperatures during June and plenty of water, we can expect corn plants to be tall this year,” he said.

“Except where roots have been in water for a week or more, fields and parts of fields where crop roots are still supplied with oxygen continue to show good canopy color. Much of the early-planted crop is in the rapid nitrogen uptake period, from about V9 through tasseling, during which the crop takes up as much as 6 or 7 lb of nitrogen per acre per day,” he added.

Nafziger is continuing to monitor soil nitrogen in an ongoing nitrogen-tracking study that is described here. The most recent samples, taken before the end of the recent deluge, did not show the large losses in soil nitrogen that might have been expected with such high rainfall.

“We know these numbers are variable and that we need to be cautious in using them, but the fact that soil nitrogen didn’t decrease sharply, especially at Urbana where so much rain fell, provides some confidence that losses have not been very high,” he said. “The crop had also taken up some nitrogen by the time of the last sampling, but not enough to draw down soil nitrogen by very much.”

The percentage of nitrogen found as ammonium increased some form early to mid-June, reflecting an increase in mineralization as soils warmed up, and perhaps some loss of nitrate, Nafziger explained.

“As plants begin to take up nitrogen at a rapid rate, we can expect soil nitrogen to drop, though nitrogen losses and mineralization will both affect the rate of change,” he said. “Over the next few weeks, we expect that the plants (canopy color) will be a better gauge of nitrogen availability to the plant than will amounts of nitrogen we measure in the soil.”

The question that remains, without a solid answer, is whether nitrogen levels might slip below those needed to maintain crop growth before uptake starts to slow. “From what we’re seeing so far that seems unlikely, at least if rains slow before too many more days,” Nafziger said.

“A more immediate question is whether the pale green or yellow spots in fields need nitrogen applied now in order to prevent serious yield loss. Rapid loss of color in places where water stands comes from loss of root ability to take up nitrogen, not from loss of nitrogen from the soil,” he said, adding that this is because parts of fields where roots are in aerated soil are not showing deficiency.

The extent to which roots of plants in wet or flooded soils will recover will not be known until soils dry and re-aerate enough for root function to return. Adding nitrogen before then will do nothing for the plants, and if soils remain wet or flooded, some of this nitrogen will be lost before the plant has a chance to take it up, Nafziger said.  

“Aerial application of urea is not inexpensive, and while it can test our patience, waiting until soils dry out for a week or more before deciding that more nitrogen is needed is the best course of action. Our hope is that a lot of acres will return to green once soils dry out.

“Even if that happens, we expect such areas to have lost yield potential, and the larger the plants were when first flooded and the longer soils stay wet, the larger will be the loss. Adding nitrogen now will do nothing to fix this,” he added.

As plant size and leaf area increase, the ability of the crop to help move water out of the will increase as well so the crop itself will help to dry the soils and will speed progress toward aerated soil conditions.

“Water loss in yellow, root-damaged corn that is standing in wet soils is very slow, so we won’t see much help there. We even see drought stress symptoms such as curled leaves where plants are standing in water, because such roots are so disabled,” Nafziger explained.

“Our best hope is to get two weeks of weather without much rain and with average or below-average temperatures to help get the crop back on track. Even then, plants in some places will be so damaged that they can’t recover,” he added.

U of I study: As siblings learn how to resolve conflict, parents pick up a few tips of their own

Published June 25, 2015

URBANA, Ill. – When children participated in a program designed to reduce sibling conflict, both parents benefited from a lessening of hostilities on the home front. But mothers experienced a more direct reward. As they viewed the children’s sessions in real time on a video monitor and coached the kids at home to respond as they’d been taught, moms found that, like their kids, they were better able to manage their own emotions during stressful moments.

“Parenting more than one child is stressful, and until now, there have been few ways to help parents deal with their own distress when children squabble. Many parents, especially mothers, use how their kids are getting along as a barometer for how well they’re doing as a parent. This is true even though virtually all siblings have some conflict,” said Laurie Kramer, a University of Illinois professor of applied family studies and co-author of the study.

When children fight with their siblings, they learn important lessons, such as how to settle, negotiate, and compromise. They begin to see conflict as a problem they can solve, said Niyantri Ravindran, a graduate student in Kramer’s and Nancy McElwain’s laboratories and lead author of the study.

These findings are well established, but what scientists did not yet know was whether parents also benefit when their offspring learn to interact more positively.

The study compared parents of siblings in Kramer’s More Fun with Sisters and Brothers Program with a control group composed of parents of non-participants. In families participating in the program, parents reported that the intense negative emotions they experience when their children fight were reduced as their children learned to get along better. Importantly, this was true for both mothers and fathers.

The More Fun with Brothers and Sisters program is a five-session intervention that teaches four- to eight-year-olds a set of social and emotional competencies that are important for good sibling relationships. These skills include how to see a problem from a sibling’s perspective, how to identify and talk about a wide range of emotions, how to calm themselves when they’re experiencing intense feelings, and how to manage conflicts, she said.

The More Fun with Sisters and Brothers Program operates on the premise that sibling relationships don’t always need to be conflictual— with some work, they can be vastly improved. 

“We sometimes have to be very intentional and teach our children how to interact well with each other,” Kramer explained. “We can’t expect young children to figure out how to manage these complex relationships on their own.”

In addition to watching the sessions on a closed circuit TV, parents received a handout after each meeting that described the session’s objectives, the words used to describe the relationship skills, and specific suggestions for what parents could say to guide children to manage a conflict using the skills the children have learned.

To encourage families to use the skills at home where they really need them, the researchers sent home lesson-specific bedtime stories, a board game with cards and questions, an activity book, and a CD with a rap song that summarizes the skills the siblings learned.

It is notable that the study found that not only do siblings profit from More Fun with Sisters and Brothers, parents do as well. But why did moms and dads differ in the ways they benefited from the program?

Studies show that fathers and mothers interact with children differently. “Dads tend to get more involved with their kids when they are playing whereas mothers tend to coach their children more,” Kramer said.

“As mothers watched us work on these concepts with their children and did the homework we’d slipped in, they learned some of the same strategies that their children did, and that helped them to better handle their own emotions.

“Mothers appear to have incorporated the skills their children were taught into the way they manage their own emotions. For example, they were significantly more likely to reframe their children’s bickering as a normal and manageable part of the sibling relationship and were less likely to let their emotions interfere with being an effective parent,” Kramer said.

In contrast, fathers who noticed more warmth between their children following the program were better able to manage their negative emotions when their children did squabble. This may be because they now felt more confident that their children would be able to manage any conflict that did erupt as a result of the skills they learned from the program.

“Even though the More Fun with Sisters and Brothers intervention is child-focused, the new study shows that this program can actually help the entire family system,” Kramer said. 

“Fostering Parents’ Emotion Regulation through a Sibling-Focused Experimental Intervention” appears in the June 2015 issue of the Journal of Family Psychology. Co-authors are Niyantri Ravindran, Nancy L. McElwain, and Laurie Kramer, all of the U of I, and Jennifer M. Engle, a U of I alumna, now of Vanderbilt University. A grant from USDA funded the research.

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