Fertilizer Stash in the Soil

December 8, 2012 03:04 PM

Nutrient carryover and crop prices will drive applications in 2013

While some carryover nutrients might be available to crops next spring, high crop prices for corn and soybeans will also play a major role in farmers’ nutrient use.

Nutrient carryover in a year following drought is an important consideration as farmers evaluate their crop fertility needs for 2013. Decatur, Neb., farmer Larry Mussack plans to apply only the nutrients he knows his corn crop needs. "Soil test, don’t guess," he says.

High crop prices for corn
and soybeans will maintain fertility applications

After a drought. More than 30 years of research by Harry Vroomen, vice president of economic services for The Fertilizer Institute, show that while drought does impact the ability of crops to absorb nutrients, thus contributing to carryover, that doesn’t mean farmers will automatically decrease fertility applications the following year.

Vroomen says that between 1970 and 2011, a significant drought occurred seven times in the U.S. He defines a drought as a year in which corn yields dropped by more than 15% in a given season due to inadequate moisture. In each case, he looked to determine the impact on fertilizer  applications in the year after the drought.

In the years following those seven drought years, average nitrogen application rates fell twice and increased five times. Application rates for phosphorus and potash fell three times and increased four times.

In 1988, the year most comparable to 2012, corn yields dropped by nearly 30% due to drought, Vroomen says. He reports that average fertility application rates in the following year, 1989, fell 4% for nitrogen, 9% for phosphorus and 8% for potash.

He doubts a drop in fertility applications will occur in 2013 like it did in 1989, however, because  USDA’s mid-October 2012 forecast has corn prices at $7.10 to $8.50 per bushel with a 5.6% stocks-to-use ratio. In 1989, corn prices were $2.50 per bushel and the stocks-to-use ratio was about 20%.

High crop prices encourage farmers to bump up nutrient application rates, as greater yields bring about higher revenues. On the other hand, carryover nutrients will bring those application rates back down so the net effect is difficult to predict, Vroomen explains.

On top of that, he adds, the 2013 planted acreage of corn, soybeans and wheat—the top three fertilizer-using crops—are expected to increase by several million acres. Despite the uncertainty, Vroomen is expecting little change in total U.S. nitrogen use next year. However, phosphate and potash use might decline somewhat, depending on the level of nutrient carryover in the soil.

"If a farmer is expecting $7.50 or $8 for corn next year, he won’t take the chance of missing out on that potential income," Vroomen says. "I think we’re going to see soil testing like crazy."

Back to news


Spell Check

No comments have been posted to this News Article

Corn College TV Education Series


Get nearly 8 hours of educational video with Farm Journal's top agronomists. Produced in the field and neatly organized by topic, from spring prep to post-harvest. Order now!


Market Data provided by QTInfo.com
Brought to you by Beyer