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Don’t forget phosphorus levels

The Indiana Certified Crop Advisers panel had plenty to say this month about whether or not starter fertilizer pays.

Reduced tillage may not be the only time starter pays. And you may want to apply more than just N. Here’s a closer look.

Ryan McAllister, Beck’s Hybrids, Parker City: Ohio State University looked at the economics of starter fertilizer. Starter phosphorus would have a high probability of return, based on trials in central Ohio, when planting prior to April 15 in no-till or conventional tillage when the soil test level is below 20 pounds per acre. (Editor’s note: Double parts per million to get pounds per acre.)

When no-till planting between April 15 and May 1 with a soil test below 20 pounds P per acre or conventionally planting in that time frame and P is deficient, you could expect a high probability of a yield response. Even after May 1 in no-till, if your soils are deficient in P, you could still expect a high probability of a yield response.

(Editor’s note: A “yield response” doesn’t guarantee profit. Also, the Tri-state Fertilizer Recommendations consider soil test values under 30 pounds per acre deficient.)

So, are you planting early? Do you no-till? Are your soils low in phosphorus? Your answer to the question of whether to apply starter lies in those answers.

I like investing in starter equipment if nothing more than for starter N. You have to apply it anyway, and can you name a better location to put it?

Jeff Nagel, Ceres Solutions, Lafayette: While nitrogen is the key nutrient for starter responses in Indiana, most studies show that a nitrogen and phosphorus combination is better. In some sandier and low-organic-matter timber soils, we’re seeing a response to the addition of ammonium thiosulfate with 2- by 2-inch starter. Two gallons of ATS per acre supplies 5 to 6 pounds of sulfur.

Seek the starter payoff

Here’s an example that illustrates what it would take to make money converting to starter fertilizer. Assume that you can convert your planter for a one-time expense of $7,500 and that you grow 1,500 acres of corn each year.

Over five years, that works out to about $1.40 per acre, counting interest cost but no value for starter equipment after five years.

Assume you apply 100 pounds per acre of 10-34-0. As noted by Ryan McAllister, you can’t count the N cost against the starter investment because the N must be applied sometime. Simply count the amount applied in the total of N applied per acre for the season.

That leaves the cost of phosphorus. Assume your cost is $15 per acre that you wouldn’t apply this year otherwise. Assuming steady fertilizer prices over five years, the investment will cost you $16.40 per acre per year.

In the chart above, note the yield response needed at various corn prices to first breakeven, then return a profit for starter fertilizer. Realize that these are just estimates.

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Source: Indiana Prairie Farmer

This article published in the February, 2012 edition of INDIANA PRAIRIE FARMER.

All rights reserved. Copyright Farm Progress Cos. 2012.