Renewable Farming

Agronomist Jim Porterfield: Soybean growers may be “leaving $24 an acre on the table”

A detailed analysis of Midwest soil nutrient deficiencies by research agronomist Jim Porterfield indicates that soybean growers may be losing $24 per acre by overlooking nutrient deficiencies which have crept up on them the past several years.

June 22, 2018 — A summary of Jim’s study will appear in an August issue of No-Till Farmer, but Jim is allowing us to post the entire report here as a PDF.  Jim is a researcher at Arise Research and Discovery, Martinsville, Illinois.  He has conducted several field studies for us in previous years, and his career has focused on enhancing soil health and fertility.

We encourage you to download and read Jim’s full analysis, and file it as a reference with your soil test results for a benchmark reference. For now, here are key points:

1. About 60% of soil tests now reveal sulfur deficiencies. This emerged in an extended review of A&L Labs soil test data in the Great Lakes region. “The reports show an average of 8 to 9 parts per million, which are very low values,” Jim notes.  For many years, farmers received “free” sulfur from emissions by coal-fired power plants. That’s over. We’re including the A&L chart below, drawn from Jim’s report.

A survey by No-Till Farmer showed that corn growers have typically responded by raising their sulfur applications — but most soybean growers have not.

2. Boron deficiencies have also crept up on Midwest growers since 1996. Almost three-fourths of the A&L Labs reports show no more than 0.50 ppm of this critical element. Porterfield and other agronomic consultants have for several years been urging applications of boron to overcome this shortage. Porterfield cites a No-Till Farmer survey indicating that only 17% of respondents are applying supplemental boron.

Porterfield’s report points out: “Entomologist Dr. Tom Dykstra calls boron a ‘sugar elevator’ in corn. If there is not enough boron, the sugars do not reach high enough brix levels. Brix should be higher than 14 to make the plant disease and insect resistant.”

The final pages of Jim’s analysis offer excellent background advice on using sap analysis to identify other potential deficiencies which rob yields. He’s alert to the need for silicon, which a few crop consultants are beginning to recommend. He adds, “Try using both expanded 16 element soil tests (including Silicon, Selenium, Molybdenum, Cobalt and EC) and petiole or leaf sap tests (which include 22 nutrients) to find out what’s really going on.”

Most Midwest soils are showing sulfur deficiencies


You can quickly remediate soybean deficiencies of critical traces this season by foliar feeding. If you do that, we of course recommend that you enhance the coverage, absorption and metabolism of your foliar nutrients with WakeUP Summer. The chart below comes from one of the earliest foliar-feeding analyses we did, showing that WakeUP substantially increased soybean tissue content of trace elements. The micronutrient blend containing those nutrients was sprayed while pods were filling. 

The point: Whatever your nutrient need, foliar applications will be more efficiently used by the crop if WakeUP Summer is tank-mixed at 5 ounces per acre.