Source: South Dakota State University

Producers should calculate their 2009 fertilizer needs now to save money.

Nitrogen fertilizer prices have declined since last summer, but prices are still relatively high, said Ron Gelderman, professor of plant science at South Dakota State University.

He said the price of nitrogen per pound today is more than doubled when compared to prices in 2003 for corn and wheat growers.

"In 2003, a bushel of corn could purchase nine pounds of nitrogen, and a bushel of wheat could purchase 14 pounds," Gelderman said. "Today, with corn, we're looking at about six pounds N per bushel, and about 10 pounds N per bushel of wheat."

These changes indicate a reduced profitability with added nitrogen. "But there are some things producers can do to still make a profit from added N, foremost among them is knowing both the need for added N and the rate of N to apply," Gelderman said. "Conducting a deep nitrate-nitrogen soil test, at depths of two feet, will determine additional N needs. Finding out how much available nitrogen you already have in the soil is like getting free fertilizer."

Reducing rates of nitrogen per acre is another option. "Several studies show that modest reductions - cutting rates by 15 to 25 pounds per acre - are prudent now for corn and wheat," said Gelderman. "Using nitrogen credits for legumes and manure is yet another way to save on N input expenses."

The average nitrogen credit from a previous crop of soybeans or field peas is 40 pounds per acre, and can lead to savings of more than $20 per acre.

"If manure is available, make sure to credit the available and potentially available N from this source," he said. "Depending on purchase, hauling, and spreading costs, this source can be an excellent value for your crop needs."

Citing a recent SDSU study, Gelderman said manure works as well or better than fertilizer nitrogen when applied at recommended rates.

Timing is another way to save money with nitrogen, Gelderman said.

"Apply it just before planting or side-dress in most cases, as this limits the amount of time for potential loss to occur," Gelderman said. "No-till is an exception. N should be broadcast on the soil surface in early spring when temperatures are lower. This allows for more time for rainfall to occur which reduces potential gaseous losses."

Gelderman reminds producers to consider nitrogen rates in other types of fertilizer, such as phosphate. He said an application of 60 pounds of phosphate as DAP, (18-46-0) adds 23 pounds of N per acre, at a value of about $13.

"Nitrogen fertilizer still has a high-profit potential when using these management guidelines," Gelderman said. "Using realistic yield goals, planting more legumes, and pricing different N sources can save on your fertilizer budget as well."