Phosphorus also makes a difference. “Phosphorus stimulates early root formation, increases tillering and increases seed size.”

But, unlike nitrogen, phosphorus is stable. “It stays put. If farmers apply phosphorus to the surface it doesn’t migrate into the root zone,” he said.

“We need to incorporate phosphorus to five or six inches. That will improve uptake substantially and increases production potential. Phosphorus prices are close to nitrogen costs, so we need to put it where the plant can take advantage of it.”

McFarland said he’s seen more potassium deficiencies than usual the past few years. “And I’m not sure why. It could be that fields have been cropped for many years, and natural soil levels are decreasing.  And, under dry conditions, root uptake of soil potassium already is limited. But potassium is important. It plays a role in cold hardiness and water use efficiency.”

He also cautioned growers about “non-traditional” fertilizer products. “With current high nutrient prices, silver bullets are being marketed to producers to enhance fertilizer efficiency. The problem is that often no research is available to back up many of these claims. Be sure to have independent, non-biased research before using a new product.”

Humic acid is a product that’s been touted in recent years as a means of enhancing fertility. “We’ve looked at it in cotton, corn and grain sorghum and saw no response compared to traditional products.”

He said humic acids occur naturally in the soil anyway, “probably from one-half to one ton per acre. So if we only add one to three gallons per acre it’s not likely to have much impact.

“Look for sound scientific data before deciding to use any new product.”

Organic nutrient sources, such as chicken litter, can offer “real bargains.” The biggest factors will be transportation cost and moisture content. If a farmer can have chicken litter delivered and spread for $65 to $75 a ton, he should do the math and see how it compares to standard inorganic products. “Also, do an analysis on compost or manure to determine what’s in it and then compare that dollar to dollar with inorganic fertilizers.”

But, whether it’s chicken litter, compost or typical fertilizer products, McFarland says the keys remain the same. Select the type of fertilizer, the rate, the method and the time of applications based on crop conditions, moisture and intended crop use. And measure—soil sample—to make certain that what you apply is exactly what you need.

rsmith@farmpress.com