Farm Talk


June 11, 2013

Farmers must apply fertilizer in growing fields

Parsons, Kansas — The yellow leaves on corn plants mean one thing. Nitrogen fertilizer applied last fall or early this spring is gone. It washed deep into the soil, beyond reach of the young roots.

That means most fields will need additional nitrogen to reach full yield potential, says Peter Scharf, University of Missouri Extension soil scientist.

“Anhydrous ammonia applied last fall is most at risk,” Scharf said. The anhydrous is a gas, but dry or liquid nitrogen applied this spring, pre-plant, also leached down into the soil.

Farmers need to think about how they can apply nitrogen into the growing cornfields, Scharf says.

Fertilizer application equipment must be driven over the field between growing corn rows. While the corn is still short, tractor-powered equipment can be used to side-dress nitrogen into the soil near the rows.

“Equipment may become a challenge,” Scharf adds.

As corn grows taller, high-clearance equipment with spinners can be used to broadcast dry fertilizer over the top of the field. That equipment may be hard to find.

Increasingly, farm service companies are equipped to apply fertilizer over growing corn.

Some growers are considering spraying liquid nitrogen over the top of corn up to 16 inches tall. “We tried a full rate of nitrogen on some seedling corn this year and it looks fine,” Scharf says. “On bigger corn, a foot tall, we burned it pretty bad, but it’s growing back. That won’t hurt yield much.

“That’s my last choice for how to apply extra nitrogen, but if you can get it on before knee high, it’s better than doing nothing.”

Continued rainfall creates another problem. Wet soils delay getting equipment back into the cornfields.

Scharf urges farmers to not abandon the idea of getting additional nitrogen applied, no matter how late.

“We’ve seen no loss on yield when nitrogen is applied to corn up to 4 feet tall,” he said. “We've seen yield response right up until almost tasseling time. If your livelihood depends on growing corn, it will pay to apply the nitrogen.”

Deep-core soil samples can be taken for nitrogen tests. “That is hard work,” Scharf adds. “If the corn is yellow and not growing, it needs nitrogen. Don’t wait for a soil test.”

However, Scharf urges farmers to make a plan for applying the nitrogen, soon. Arrangements should be made now to assure a supply of fertilizer to apply.

“Fertilizer dealers plan to have their bins and tanks empty by the end of planting season,” Scharf says. “They don’t plan to carry fertilizer over to the next season. But if they know they can sell it to you, I’m sure they will get it for you. Just arrange to have it when you need it.”

Scharf talked to soil consultants who did deep-core sampling. “They are not finding normal nitrogen levels in the top foot of soil. Most has moved down to the second foot.”

Corn plants need nitrogen to grow roots that will go deep into the soil.

Much of the corn across Missouri was planted five to six weeks later than farmers wanted to plant. “When the weather opened a little, they planted corn. They didn’t stop to put on fertilizer,” he says.

“Actually, people who put nitrogen on after they planted are probably in the best shape,” he adds. “Farmers in the Bootheel count on side-dressing every year. They always get an extra 10 inches of rain. They know what to do.”

Scharf and his colleague John Lory maintain the Website “Nitrogen Watch 2013” to show where nitrogen losses occur. It is based on cumulative rainfall reports from across the Corn Belt.

To access the Website, go to and click on “N Watch 2013.”

The reports are divided into well-drained and poorly drained soils. The fertilizer loss will extend later in poorly drained areas.

“There’s going to be a lot of yellow corn,” Scharf adds. £

Text Only
  • cornplantlatemay2.jpg WASDE report eases low crop price fears

    USDA’s April 9 World Agricultural Supply and Demand Estimates continued a series of recent reports that have offered corn and soybean producers a more optimistic grain-price outlook than what was expected for most of the winter, Purdue Extension agricultural economist Chris Hurt says.

    April 15, 2014 1 Photo

  • USDA: Corn acres expected to drop 4%

    The amount of American cropland devoted to corn is expected to shrink about 4 percent this year as farmers devote more acres to soybeans, the U.S. Department of Agriculture said last week.

    April 8, 2014

  • Bt-resistant rootworms ID’d in five states

    Researchers say bugs are developing resistance to the widely popular genetically engineered corn plants that make their own insecticide, so farmers may have to make changes.

    April 1, 2014

  • MU economist: Corn, bean price volatility next 5 years

    Expect volatility in the soybean and corn markets over the next five years, said Pat Westhoff, director of the University of Missouri Food and Agricultural Policy Research Institute (MU FAPRI).
    Look for corn prices to drop to $4 per bushel and soybean to $10 per bushel on average for the next five years, he said.

    March 25, 2014

  • marestail.jpg Plan now to control marestail in soybeans

    Controlling marestail in soybeans has been a big challenge for Kansas no-till producers in recent years.
    Because soybeans are generally planted later in the season, and marestail generally germinates in the fall or early spring, application timing and weed size are critical factors to successful control.

    March 18, 2014 1 Photo

  • Checking alfalfa for winter injury

    In the last couple of weeks, I’ve heard many concerns about alfalfa production for this spring.
    Cold temperatures and lack of snow cover are the two main issues producers are worried about for next season’s crop production, as certainly the alfalfa plant could die if exposed to extremely cold temperatures. In general, alfalfa plants can tolerate up to three weeks of winter injury before the plants are killed.

    March 11, 2014

  • soypods.jpg USDA reports on status of GE crops

    Genetically engineered (GE) varieties with pest management traits became commercially available for major crops in 1996.
    More than 15 years later, adoption of these varieties by U.S. farmers is widespread and U.S. consumers eat many products derived from GE crops — including corn-meal, oils, and sugars — largely unaware that these products were derived from GE crops.

    March 4, 2014 1 Photo

  • wheat-head.jpg Everest still leads Kan. wheat acres

    For the second year in a row, a variety of wheat developed by Kansas State University, is the leading variety in Kansas.

    February 25, 2014 1 Photo

  • RickReimer.jpg Innovation, exports fuel soybean demand

    Brent Hayek is revved up about potential new uses for soybeans, and he is piling up the miles to share his enthusiasm.

    February 18, 2014 2 Photos

  • red_clover.jpg Seed legumes on snowy fields

    Winter seeding clover over grass pastures works best in February. Frozen fields are ideal and a snow cover makes seeding easier.

    February 11, 2014 1 Photo

Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Seasonal Content