Nitrogen Key for No-till, Early Planting

Starter fertilizer secret for these conditions. Tom J. Bechman

Published on: Mar 18, 2004

Plant early if you like. No-till your corn into soybean stubble if you like. Or do both of these on your farm. But if you do either one, and especially if you do both, also do yourself a favor. Make sure to apply starter fertilizer, and pick a starter combination high in nitrogen (N).

That sound advice comes from Dave Nanda, director of research for Stewart Seeds, Greensburg, Ind. Nanda is a firm believer in feeding plants enough N early in the season. That's why he recommends starter fertilizer high in N.

Traditionally, most starter fertilizers emphasized phosphorus (P). It can still be important, especially if soil tests for P are medium or even lower. And there is growing evidence that potassium (K) may be important in starter situations. The problem for those who want to apply K can often be mechanics. It's difficult to prepare a liquid fertilizer blend with large amounts of K included.

Many farmers took starter fertilizer units off their planters 20 years ago, seeing little or no yield response in most cases. University data, much of it collected by Dave Mengel, then a Purdue University agronomist, also indicated that while corn might look greener and healthier early in the season, it didn't necessarily yield better in the final analysis.

"What we need to remember is that those tests ran by universities were almost all planted in early May," says Bob Nielsen, a Purdue University corn specialist. "Most folks weren't planting in mid-April back then."

No-till Factor

No-till is the other key that tips the scales toward applying starter fertilizer. Barry Fisher, Indiana Conservation Tillage Initiative (ICTI), explains that N is tied up in a heavy residue situation early in the season. It will become available, so it's not lost. But the kicker is that corn plants will determine ear size, row length and number of kernels per row before that could likely occur.

"That's why you absolutely want N in your starter fertilizer in no-till," Fisher says. "Then sidedress the rest of your N early. I like to get it out there and injected as soon as you can row the corn."

The N tied up in residue returns to useful form after the temperature warms up, Fisher relates. You can expect as much as 30 to 40 pounds per acre of N to return into usable form by mid-summer.